Management of cardiac conduction abnormalities and arrhythmia in aircrew

12 Pages·2017·0.56 MB·English

Standards
Management of cardiac conduction
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abnormalities and arrhythmia in aircrew rt: firs
Norbert Guettler,1 Dennis Bron,2 Olivier Manen,3 Gary Gray,4 Thomas Syburra,5 t pu
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Rienk Rienks,6 Joanna d’Arcy,7 Eddie D Davenport,8 Edward D Nicol7 lis
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1German Air Force Center ABSTRACT As described in Coumel’s triangle of arrhyth- s 1
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2Aeromedical Centre, Swiss Air 3
Force, Dubendorf, Switzerland is the main disqualifier in a substantial proportion of substrate, the trigger factor, and the modulation 6/h
3Aviation Medicine Department, aircrew. Aircrewii often operate within a demanding factors, of which the most common is the auto- ea
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a positive gravitational force, from head to feet (+Gz)) elongation of the heart5; additionally, this exposure 0
Medical Establishment, Toronto, 1
Ontario, Canada in high performance aircraft. Aeromedical assessment is leads to rapid stimulation/inhibition of the sympa- 8-3
5Cardiac Surgery Department, complicated further when trying to discriminate between thetic and parasympathetic systems, and so this is 1
3
Luzerner Kantonsspital, Luzern, benign and potentially significant rhythm abnormalities a highly arrhythmogenic environment for aircrew, 0
5
6SDweitpzaerrtlmanednt of Cardiology, in aircrew, many of whom are young and fit, have a especially those with pre-existing susceptibility. 7 o
University Medical Center resultant high vagal tone, and among whom underlying Benign dysrhythmias such as sinus arrhythmia, low n 1
Utrecht and Central Military cardiac disease has a low prevalence. In cases where a degree atrioventricular (AV) block, and premature 3
Hospital, Utrecht, The significant underlying aetiology is plausible, extensive atrial or ventricular beats are commonly observed N
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SMeervdiiccein, eR,A RFA CF eHnetrnel oowf ,A viation decision regarding restriction of flying activity will be with more significant arrhythmias suzch as AF or ber 2
Bedfordshire, UK dependent on several factors including the underlying recurrent NSVT. This is often in relation to cardiac 0
8Aeromedical Consult Service, arrhythmia, associated pathology, risk of incapacitation abnormalities found during subsequent investi- 18
USAF School of Aerospace and/or distraction, the type of aircraft operated, and the gation of aircrew, in whom +G has precipitated . D
Medicine, Wright-Patterson AFB, z o
Ohio, USA specific flight or mission criticality of the role performed these events, that may have flight safety implica- w
by the individual aircrew. tions.6 Particularly worrisome complications of nlo
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Correspondence to arrhythmias in aircrew are incapacitation secondary d
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Dr Edward D Nicol, Aviation INTRODUCTION to pre-syncope or syncope, or distraction due to d
Medicine Clinical Service, RAF Cardiovascular diseases are the most common symptoms such as palpitations or dizziness that may fro
Centre of Aviation Medicine, m
RAF Henlow, Bedfordshire, cause of loss of flying licence globally, and cardiac interfere with aircrew duties and negatively impact h
SG16 6DN; [email protected] arrhythmia is the main disqualifier in a substantial flight safety. ttp
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common arrhythmias seen in aircrew.2 resultant high vagal tone, and among whom under- j.c
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Aircrew often operate within a demanding phys- lying cardiac disease has a low prevalence. m
iological environment, that potentially includes As with all individuals, arrhythmia and conduc- o/
exposure to sustained acceleration (usually tion disturbances in aircrew may be caused by n F
resulting in a positive gravitational force, from underlying structural heart disease, or endocrine eb
head to feet (+Gz)) in high performance aircraft. or other non-cardiac organic disorders. Therefore, ru
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iEvidence-based cardiovascular risk assessment in aircrew poses significant challenges in the aviation envi- , 2
ronment as data to support decision making at the low level of tolerable risk in aviation is rarely available 0
2
from the published literature. As a result, there are discrepancies between aviation authorities’ recommen- 3
dations in different countries, and even between licensing organisations within single countries. The North by
Atlantic Treaty Organization (NATO) HFM-251 Occupational Cardiology in Military Aircrew working g
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group comprises full-time aviation medicine and aviation cardiology experts who advise both their mili- e
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tary and civil aviation organisations including, but not limited to, the US Federal Aviation Authority t. P
© Author(s) (or their (NFaAtAio)n, atlh eA eUroKn Cauivtiicl sA Svpiaatcieo nA dAmuitnhiosrtritayt i(oCnA (AN)A, StAhe). ETuhreo preecaonm Amvieantdioanti oSnasfe otyf tAhgise ngcryo u(pE AarSeA a) sa an dr etshuelt UoSf rote
epmerpmloityteerd( su))n d2e0r1 C8.C R BeY-u-NseC . No a 3 year working group that considered best clinical cardiovascular practice guidelines within the context cte
of aviation medicine and risk principles. This work was conducted independently of existing national and d
caonmd mpeerrmciiasls iroen-us.s eP.u Sbelies hriegdh ts transnational regulators, both military and civilian, but considered all available policies, in an attempt to by
by BMJ. determine best evidence-based practice in this field. The recommendations presented in this document, co
and associated manuscripts, are based on expert consensus opinion of the NATO group. This body of work p
y
To cite: Guettler N, Bron D, has been produced to develop the evidence base for military aviation cardiology and to continue to update rig
Manen O, et al. Heart the relevant civilian aviation cardiology advice following the 1998 European Cardiology Society aviation h
2019;105:s38–s49. t.
cardiology meeting.
s38 Guettler N, et al. Heart 2019;105:s38–s49. doi:10.1136/heartjnl-2018-313057
Standards
Table 1 Recommendations for ECG findings in aircrew H
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Normal ECG variants Ffuorrt hneorr minavle vsatirgiaantitos,n c iof…nsider EicneCvrGeti sfifitcingadatiitnoigonsn rfeoqru aiirricnrge wfu rmtheedri cal EdaCcucGteie pfistn audbnilnleeg sasse dtrriosemqauteeaddliic,f aywiln irtgihs kfroers ualitricnrgew art: firs
t p
Sinus arrhythmia Sino-atrial block (<3 s/day, <4 s/night) Sinus arrest u
Sino-atrial block >3 s during day, >4 s night blis
Ectopic atrial rhythm with inverted P waves h
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Sinus bradycardia ≥40 beats per min (bpm) Sinus bradycardia <40 bpm Idioventricular rhythm d a
Junctional rhythm s
1
Sinus tachycardia >100 bpm Persistent sinus 0
tachycardia >100 bpm at rest .1
1
I° atrioventricular (AV) block – PR <300 ms I° AV block – PR >300 ms 36
II°AV block- Mobitz type I (Wenckebach) First appearance at age >40 years or Second degree AV block (Mobitz type II) /h
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if frequent, especially while awake Third degree AV block a
Incomplete right bundle branch block (RBBB) New LAFB block >40 years Complete RBBB rtjn
Left anterior fascicular block (LAFB) Left bundle branch block (LBBB) l-2
0
Left posterior fascicular block (LPFB) 1
8
Single premature atrial complex (PAC) or >1 PAC or PJC SVT >30 s or symptomatic -3
premature junctional complex (PJC) Supraventricular tachycardia (SVT) <30 s 13
0
Single premature ventricular complex (PVC) >1 PVC or ≥1 pair VT >11 beats or symptomatic 5
7
Ventricular tachycardia (VT) ≤11 beats o
Short PR interval 90–120 ms with no evidence Very short PR <90 ms Asymptomatic ventricular pre-excitation Wolff-Parkinson-White (WPW) syndrome n 1
of delta waves 3
N
Isolated QRS voltage criteria for left ventricular Elevated blood pressure, body mass Left ventricular hypertrophy with strain o
hypertrophy, especially in young people index >30, age >40 years, or new ve
finding m
b
Atrial enlargement Accompanied by axis deviation e
Right ventricular hypertrophy (R wave in V plus r 2
1 0
S wave in V or V >10.5 mm) 1
5 6  8
ST segment depression and/or negative T wave Diffuse T wave abnormality or ST changes . D
only in lead III o
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QTc prolongation (QTc <470 ms) QTc >470 ms but <500 ms QTc >500 ms n
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Early repolarisation (benign form) – no evidence Brugada type 2 Brugada type 1 pattern a
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of delta waves e
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when investigating arrhythmias in aircrew, a thorough cardiac APPROACH TO SCREENING IN AIRCREW h
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cations for flight safety. ment intake, a physical examination, and a 12-lead ECG. j.c
Close liaison with subspecialty electrophysiologist expertise Symptoms such as palpitations (regular or irregular), dizzi- om
is recommended to ensure all potential options are explored as ness, syncope or presyncope should lead to suspicion of an o/
this is a rapidly changing field. Increasingly, aircrew are recom- n
arrhythmic aetiology. F
mended to undergo, or have already undergone, catheter ablation Many abnormal ECG findings may be acceptable in young, e
b
or device implantation, and both short- and long-term outcome fit individuals with high vagal tone, whereas others mandate ru
data must be considered when determining aircrew licensing.7–9 a
further investigation and may lead to restriction, or with- ry
This paper describes an approach to electrophysiological 6
screening, further investigation, and risk stratification of elec- drawal, of flying privileges. A more detailed summary of ECG , 2
abnormalities and their relevance and consequences for aero- 0
trical abnormalities and arrhythmias in aircrew. Risk stratifi- 2
medical investigation are presented in table 1. In those where 3
cation for aeromedical disposition depends on the presenting b
there may be flight safety consequences, further investigation y
arrhythmia, associated pathology, risk of incapacitation and/or g
is mandated. u
distraction, and specific aircrew duties. e
s
iiAircrew: Aircrew are defined somewhat differently in civil and military aviation. NATO and the International Civil Aviation Orga- t. Pro
nization (ICAO) delegates the definition of aircrew to national authorities. In the civilian sector aircrew are often categorised as te
flight crew (pilots)/technical crew members and cabin crew, with separate regulation for air traffic controllers (ATCO). The military cte
define aircrew more broadly as “persons having duties concerned with the flying or operation of the air system, or with passengers d
or cargo when in flight”. From a risk perspective, professional (commercial) pilots have a higher attributable risk than private pilots by
and non-pilot aircrew. Controllers are considered to have an attributable risk equivalent to professional pilots. From a cardiovascular c
o
perspective, aircrew whose flying role includes repetitive exposure to high acceleration forces (Gz) comprise a subgroup who, due to p
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the unique physiological stressors of this flight environment, often require specific aeromedical recommendations. A more detailed rig
description of aircrew is available in table 1 of the accompanying introductory paper on aviation cardiology (Nicol ED, et al. Heart h
t.
2018;105:s3–s8. doi:10.1136/heartjnl-2018-313019).
Guettler N, et al. Heart 2019;105:s38–s49. doi:10.1136/heartjnl-2018-313057 s39
Standards
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Figure 1 Spectrum of ambulatory patient monitoring systems. From left to right, the duration of monitoring increases leading to an increase of the -3
diagnostic yield. 1
3
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5
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Second level investigation of metabolic disorders. Vagally-mediated syncopal attacks are o
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Further investigation should include Holter monitoring (24 hours common and if isolated can be considered benign, but recurrent 1
3
to 7 days), echocardiography and exercise ECG, as well as labo- or unprovoked syncope requires careful evaluation. N
o
ratory investigations. Haematological and biochemical samples Careful aeromedical evaluation is necessary to elucidate the v
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should include a blood count, electrolytes, and thyroid hormone cause of syncope and to determine the risk of recurrence. Neuro- m
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assessment. Other investigations may be required (ie, urinary genic syncope refers to a reflex response causing vasodilatation e
catecholamines, etc). When undertaking Holter assessment, the and/or bradycardia, rarely tachycardia, leading to systemic r 2
0
longer the monitoring duration, the more likely it is to reveal hypotension and cerebral hypoperfusion. Types of neurogenic 1
8
abnormal results. If episodic, telemetric ECG monitoring and/or syncope include neurocardiogenic (vasovagal) syncope, carotid . D
external/implantable event/loop recorders may be appropriate. sinus syncope and situational syncope . The overall recur- o
w
In certain scenarios, in-flight Holter monitoring may be required rence rate of vasovagal syncope may be as high as 30%.15 In n
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(figure 1). While the sensitivity and specificity of exercise ECG aircrew, a thorough investigation with ECG, echocardiogram, a
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for the detection of coronary artery disease (CAD) is low, it exercise ECG and, in some cases, tilt table and an implantable e
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provides useful information about cardiovascular fitness, stress loop recorder (ILR) is often required if more than one syncopal fro
induced arrhythmias, QT interval changes with exercise or exer- episode has occurred. International guidelines regard ILR m
cise induced bundle branch blocks. If hypertension is suspected, implantation as a class IA indication in the early phase of evalua- h
ambulatory blood pressure measurement should be included. thiiognh irni spka ptiaetnietsn wts iitnh wrehcoumrre an tc osymnpcorephee onfs iuvne ceevrataluina toiornig iwn,a so rn oint ttp://h
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TInh irad m leivneolr iitnyv eosft icgaasteiso nin/tvraesaivtme eenletctrophysiologic (EP) testing sucInce assnf ualv iina tiidoenn ctiofnyitnegx ta, na usnyndceorlpyainl ga tctaauckse m.16ay lead to sudden art.b
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and/or treatment may be required. If invasive EP testing reveals incapacitation and loss of aircraft control,17 while pre-syncope j.c
a target for catheter ablation, it is often performed immediately. that causes distraction or incapacitation may also be potentially o
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In certain arrhythmias, genetic testing may be indicated. catastrophic. o/
In some instances, specialist pharmacological testing may be n
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indicated to confirm or refute a diagnosis—that is, adenosine e
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with an accessory pathway with antegrade conduction, or ajma- ru
line in the case of suspected Brugada syndrome. Table 2 Recommendations for investigation of arrhythmias a
ry
In aircrew flying in high-performance aircraft, human centri- Recommendations 6
fuge testing to assess the response of arrhythmias to sustained , 2
Medical history including family history, physical examination, Highly 0
acceleration may be useful. If underlying structural disease or 2
and ECG should be performed for all cases of suspected cardiac recommended 3
CAD is suspected, stress echocardiography, cardiovascular arrhythmia b
y
CT, cardiac MRI or invasive coronary angiography may be Second level evaluation for arrhythmia should include Highly g
indicated (table 2).10–14 ambulatory ECG monitoring, echocardiography, an exercise ECG, recommended ue
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SSyynnccooppee is caused by transient global cerebral hypoperfusion aImnne dcaa shsuaerese mmofae tsnoutls oipsge irccetacelo dam nhmdyp ebenirodtceehndes.mioinc aalm abnuallaytsoisr.y blood pressure t. Prote
and is defined as a transient, self-limiting loss of consciousness, Depending on the type of arrhythmia and the aircrew role, Recommended cte
third level evaluation with invasive electrophysiologic study d
with rapid onset and spontaneous complete recovery after a plus possible catheter ablation, genetic testing or specific b
short time period. Pre-syncope occurs when there are symptoms pharmacological tests may be appropriate. y c
of cerebral hypoperfusion without a loss of consciousness. The Exclusion of underlying cardiac diseases may require cardiac MRI, op
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aetiology of loss of consciousness is diverse and may be caused cardiac CT, stress echocardiography and/or invasive coronary rig
by neurogenic reflexes, cardiovascular disease or arrhythmias, angiography. For aircrew of high performance aircraft, centrifuge h
neurologic or psychiatric conditions, medications, and a variety testing to evaluate response to Gz acceleration may be useful. t.
s40 Guettler N, et al. Heart 2019;105:s38–s49. doi:10.1136/heartjnl-2018-313057
Standards
Table 3 Recommendations for syncope Table 4 Recommendations for bradyarrhythmias and conduction H
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RCaerceofuml maeernodmaetdioicnasl evaluation is necessary to elucidate the cause Highly Rdeisctoumrbmaenncdeast ions art: firs
of syncope and to determine the risk of recurrence. recommended Symptomatic sinus bradycardia—asymptomatic pauses >3 s Highly t p
Recurrent syncope of any cause should be disqualifying for Highly during daytime and >4 s at night; a newly discovered first degree recommended u
b
aircrew duties, if an underlying disease cannot be treated or if the recommended atrioventricular (AV) block with a PR interval >300 ms—should, at lis
triggering factor cannot be adequately controlled. least temporarily, lead to withdrawal of flying privileges. h
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Aircrew with a single episode of syncope associated with a clear Highly Asymptomatic sinus bradycardia—first degree AV block up to Highly d a
precipitant, likely neurocardiogenic (vasovagal) in origin, or G recommended a PR interval of 300 ms; and second degree (Mobitz type I) AV recommended s
induced in the centrifuge, should be able to return to unrestricted block—is most likely caused by an increased vagal tone and does 1
0
flying duties. not require further investigation. .1
1
If syncope is orthostatic or neurogenic and the triggering factor Consider Aircrew with complete right bundle branch block should undergo Recommended 3
6
can be adequately controlled, and the recurrence rate is within the cardiological evaluation to exclude an underlying disease. Over /h
limits of the 1% safety rule, return to restricted aircrew duties may age 40, coronary assessment may be considered. In the case of e
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be possible after a period of observation. normal results an unrestricted fit assessment is possible. rtjn
Aircrew with complete left bundle branch block should initially be Recommended l-2
assessed as unfit and undergo thorough cardiological evaluation. 0
A single episode of loss of consciousness, if associated with a Under age 40, a coronary assessment should be considered; 18
clear precipitant, and likely neurocardiogenic (vasovagal) origin, over age 40, it is recommended. If an underlying disease can be -3
1
should not lead to aircrew being restricted in their flying duties— excluded, return to unrestricted aircrew duties may be possible, 3
0
for example, if associated with venepuncture or prolonged with regular (annual) follow-ups. 57
standing, without incontinence, and followed by complete and Unrestricted flying with left anterior fascicular block (LAFB) and Recommended o
n
rapid recovery. Additionally, a syncopal episode associated with left posterior fascicular block (LPFB) is possible, if there is no 1
evidence of an underlying cardiac disease. In the case of newly 3
a physiologic loss of consciousness because of reduced partial acquired LAFB or LPFB, over the age of 40 years, coronary artery N
pressure of oxygen (PaO) (eg, during hypoxia training) or a G disease should be excluded. ov
2 e
induced loss of consciousness (GLOC) in the centrifuge, may Aircrew requiring implanted pacemakers are initially unfit for Recommended m
also be deemed to be benign, if isolated. In other cases, if a clear aircrew duties. If individuals are not pacemaker dependent, lead be
precipitant is identified and the risk of recurrence is low and/or systems are bipolar and appropriately programmed, and regular r 2
the underlying condition or triggering factor can be adequately pacemaker follow-ups are performed, a return to aircrew duties 01
controlled, return to restricted flying duties may be possible after mmailiyt abrey paonsds icbolem bmaesrecdia ol np ialont sa, prpesrotrpicrtiaetde flryisikn ga,s wseisthsm ae snetc. oFnodr 8. D
a period of observation (table 3). Recurrent episodes of loss or o
qualified pilot, is recommended, w
disturbances of consciousness, orthostatic or symptomatic hypo- n
tension, or recurrent vasodepressor syncope are all disqualifying Sbeloccokn dre dqeugirree ea AfuVl lb claorcdki o(Mlogoibciatzl etyvpaelu 2a)t,i oann da nthdi radr ed uegsureaell yA V Nreocto mmended load
for aircrew duties. incompatible with aircrew duties. They may require pacemaker e
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RHYTHM AND CONDUCTION DISTURBANCES mona naa cgaesme ebny tc aansed breatsuisrn a tnod awiricllr ebwe ddeuptieensd sehnotu oldn baeir ccroenwsi droelree.d from
Bradyarrhythmias and conduction disturbances h
Sinus node dysfunction ttp
Sinus bradycardia and sinus arrhythmia are common findings in incidental finding in asymptomatic individuals, and further ://he
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cular fitness also often have increased vagal tone,18 19 and may symptoms, diurnal occurrence of Mobitz type I or in those aged j.c
have a higher incidence of junctional rhythm, and increased over 40 years at first presentation. Most aircrew with Mobitz o
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heart rate variability. These findings, in isolation, are compat- type I may be returned to unrestricted duties. o/
ible with all aircrew duties, including in single seat, high perfor- In contrast to Mobitz type I, Mobitz type II is rarely seen in n
mance aircraft. aircrew24; it is more commonly related to infra-Hisian block, Fe
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In contrast, aircrew with syncope or presyncope caused by located below the AV node, and carries a risk of progression ru
sinus bradycardia, sinus arrest or sino-atrial block should be to third degree (complete) AV block.25 Aircrew with Mobitz ary
grounded. In asymptomatic individuals, sino-atrial arrest >3 s type II and complete AV block must be investigated for under- 6
during the daytime and >4 s at night should also lead to tempo- lying structural heart disease and, although often asymptomatic, , 2
rary withdrawal of aircrew privileges (table 4).20 Such individuals aircrew are unfit for flying because of the risk of sudden cardiac 02
3
require further investigation to confirm or exclude underlying death (SCD), syncope, bradycardia-related haemodynamic b
y
cardiac disease. symptoms, and heart failure. In most cases pacemaker therapy g
u
is indicated. A review by an electrophysiologist is recommended. e
s
Atrioventricular conduction disturbance Individuals with implanted pacemakers are initially unfit for t. P
First degree AV block in asymptomatic aircrew can be regarded aircrew duties. A return to aircrew duties may be possible if indi- ro
as a normal variant up to 300 ms. It is a common finding in viduals are not pacemaker dependent, have bipolar lead systems, te
c
young athletes.21 If the PR interval exceeds 300 ms as a new and have regular pacemaker follow-up.26 The possibility of te
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finding, further investigation is recommended. During exer- pacemaker failure and the risk of electromagnetic interference, b
cise ECG (and after atropine) a significant shortening of the PR even if considered low in modern pacemaker systems,27 are y c
interval should be observed. Following such investigations, most also important factors, and aircrew are usually restricted to low op
y
aircrew can remain flying. performance aircraft that do not routinely employ equipment rig
In aircrew, the most common type of second degree heart that use high electro-magnetic frequencies (EMF). EMF sources h
t.
block is Mobitz type I (Wenckebach). In most cases this is an are common in many military aircraft and other radar systems
Guettler N, et al. Heart 2019;105:s38–s49. doi:10.1136/heartjnl-2018-313057 s41
Standards
and should always be considered by occupational physicians with RBBB and may be associated with CAD or cardiomyopathy.
H
before return to military and aircrew duties. Investigation with echocardiography, Holter and exercise ECG e
a
bloInck s oMmoeb iitnzs ttaynpcee Is ,a dnids cIrIi mcainna btieo cnh baelltewnegeinng s oecno tnhde dEeCgGre,e aAnVd iasn rgeicoogmrampheyn dsehdo,u alndd b ief ocvoenrs aidgeer 4ed0. a Itf p trheeserne taatrieo nn oC Tu ncdoerrolnyainrgy rt: firs
in aircrew invasive EP testing with measurement of the H-V cardiac abnormalities, unrestricted flying is possible without t p
interval may be helpful. follow-up investigation, in both types of hemiblock. u
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Right bundle branch block Ectopy, tachyarrhythmias, ventricular pre-excitation, and e
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Incomplete right bundle branch block (RBBB) is a very common channelopathies a
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finding in aircrew and is seen in 2–3% of routine aircrew ECGs.28 Ectopy 1
0
In isolation, it can be regarded as a normal variant and further Atrial and ventricular ectopy is frequently discovered on routine .1
investigation is not required. Individuals with complete RBBB aircrew ECGs. For aeromedical purposes, two or more atrial 13
6
(which is found in <1% of aircrew ECGs28), should undergo or ventricular ectopic beats on a standard ECG should lead to /h
further investigation for structural heart disease, despite it further assessment with a Holter monitor. On Holter moni- ea
being a normal variant in a proportion of the normal popula- toring in aircrew, atrial and ventricular ectopy is quantified as rtjn
tion. Investigation in aircrew should include an echocardiogram, the percentage of total beats and is often graded as rare (≤0.1%), l-2
an exercise ECG, and consideration of Holter monitoring. If occasional (>0.1% to 1.0%), frequent (>1.0% to 10%), and 01
underlying disease can be excluded, aircrew can be considered very frequent (>10%).36 8-3
fit to continue all duties. In aircrew aged >40 years, coronary 13
0
artery assessment may also be considered. Flying restriction and Atrial ectopy 5
7
follow-up is usually not necessary. Atrial ectopy (or premature atrial contractions (PACs)) is usually o
n
benign and does not require further investigation or restrictions 1
Left bundle branch block for aircrew, as long as they are not frequent or associated with 3 N
Left bundle branch block (LBBB) is more commonly associated haemodynamic symptoms. ov
Atrial ectopy is of aeromedical concern if associated with e
with underlying structural heart disease than RBBB and its inci- m
dence increases with age. It is not a common finding in aircrew symptoms, and if numerous, underlying heart disease should be be
and has been reported in 0.01–0.1% of healthy military aircrew excluded. At higher PAC burden, there is also a concern regarding r 2
compared with 0.2–0.7% of various civilian populations.29 30 The the potential development of AF. In patients with structurally 01
prognosis of isolated LBBB in young men is generally benign,31 ndoatrambaals eh eoafr tfsr,e tqhuee dnat taat irnia tlh eisc taorpeya awrea sc onnottr apdriecdtoicrtyi.v eO noef stmacahl-l 8. D
and the risk of progressive conduction system disease for newly o
yarrhythmia in 430 US aircrew (US Air Force (USAF) Aero- w
diagnosed LBBB has not been shown to be increased in other- n
wise apparently healthy young males.32 However, LBBB can be medical Consultation Service database), while another, small, loa
a marker of advanced CAD,33 longstanding hypertension, aortic non-aircrew study (where frequent PACs were defined as >100 de
PACs/24 hours), demonstrated that patients with frequent PACs d
valve disease or cardiomyopathy, and therefore requires investi- were significantly more likely to develop AF (HR 3.22, 95% fro
gation in all aircrew. m
Aircrew found to have new LBBB are unfit for aircrew duties CI 1.9 to 5.5; P<0.001), and more composite major adverse h
pending a thorough cardiological evaluation including echocar- cardio- and cerebrovascular events (MACCE), including isch- ttp
diography, an exercise ECG, and coronary angiography (invasive aemic stroke, heart failure and death (HR 1.95, 95% CI 1.37 ://h
to 3.50; P=0.001) at 6 years follow-up.37 This latter study e
or CT based). Under age 40, a CT coronary angiogram should a
be considered, and over age 40 it is recommended. Holter moni- demonstrates that a comparatively low burden of PACs may rt.b
significantly increase the risk of AF and adverse cardiovascular m
toring may be useful. Many patients with LBBB have underlying
left ventricular hypertrophy.34 A cardiac MRI should be consid- events in the long term. Therefore, aircrew with >1% of PAC j.co
on Holter monitoring should be considered for further investi- m
ered, especially if under the age of 40 years.
If underlying heart disease can be excluded, return to unre- gation and regular follow-up with echocardiogram, Holter and on/
stricted flying duties may be acceptable; however, many civil exercise ECG; above 5% PAC on Holter assessment, further F
e
and military licensing authorities mandate an observation period investigation is recommended, and may result in restriction of b
aircrew duties (table 5). ru
and close follow-up with further (often annual) echocardiog- a
raphy, exercise ECG, and Holter monitoring. This is primarily ry 6
to monitor for the possible development of cardiomyopathy and Supraventricular tachycardia , 2
reducing left ventricular function. Aircrew with exercise induced Supraventricular tachycardia (SVT) is defined as a run of narrow 02
LBBB should be treated similarly to aircrew with LBBB on a complex tachycardia and may be asymptomatic or associated with 3 b
resting ECG. However, coronary assessment is recommended in palpitations. It may last for seconds to days; however, sustained y g
all aircrew with exercise induced LBBB. u
e
s
Left anterior and left posterior fascicular block Table 5 Recommendations on atrial ectopy t. Pro
Left anterior fascicular block (LAFB) is seen in 1–2% of indi- Recommendations te
c
viduals without structural heart disease, while left posterior Infrequent atrial ectopy is mostly benign and usually does not Recommended ted
fascicular block (LPFB) is far less common. Both carry no appre- require further investigation or restrictions for aircrew, as long as b
ciable risk of progression to higher degrees of block.35 However, it's not associated with haemodynamic symptoms. If numerous, y c
LAFB may be associated with myocardial ischaemia and if newly ambulatory ECG monitoring is recommended. If there are >1% of op
acquired over age 40, underlying CAD should be excluded with bgeivaetns oton faumrthbeurla itnovreys EtiCgGat imono;n iift o>r5in%g tchoins siisd reercaotimonm sehnodueldd wbeit h yrig
CT coronary angiography. Under 40 years, if investigated, an h
regular follow-up. Aircrew may be restricted in their flying duties. t.
echocardiogram is usually sufficient. LPFB is often associated
s42 Guettler N, et al. Heart 2019;105:s38–s49. doi:10.1136/heartjnl-2018-313057
Standards
SVT is defined as having a duration of >30 s.38 The aetiology of return to aircrew duties may be possible, although with restric-
H
SVT include AV nodal re-entrant tachycardia (AVNRT) caused tions in many cases. Aircrew with very short runs of asymptom- e
a
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atrial tachycardias caused by foci or small re-entrant circuits in Antiarrhythmic drug therapy for SVT is unreliable and often t p
the right or left atrium (10%).39 associated with side effects that are incompatible with flying u
b
While AVNRT and AVRT often occur in otherwise healthy duties. As a result, the therapy of choice for symptomatic SVT lis
h
subjects, atrial tachycardias are often associated with structural is often invasive EP testing and catheter ablation. For most e
d
heart disease, hypertension, etc, and require investigation in SVT, ablation has a success rate >90% and adverse event rate a
aircrew to exclude an underlying aetiology. Tachycardias usually <3%.42 Ablation success rates for AVNRT and accessory path- s 1
start suddenly and are usually symptomatic, with distracting ways may be as high as 95%. Depending on the aircraft type and 0.1
symptoms such as palpitations, nausea, dizziness, or haemo- role of aircrew, many can return to previous duties. However, 1
3
dynamic symptoms like syncope or presyncope, all being of depending on the estimated recurrence rate, many aircrew who 6/h
significant concern in an aircrew population. As a result, all tach- fly high-performance aircraft, or on single seat platforms, may be e
a
yarrhythmias are initially disqualifying for aircrew and require restricted, even after clinically successful ablation. rtjn
further investigation and management. In cases of suspected l-2
SVT, information about alcohol, caffeine or supplement intake is 0
1
important, because these agents may be provocative. Asymptomatic pre-excitation 8
-3
Little data exist in aircrew populations; however, in a review Pre-excitation on a 12-lead ECG is caused by an accessory 1
3
of 430 US military aircrew evaluated for SVT over a median 8 pathway (AP) with antegrade conduction bypassing the AV node, 0
5
years follow-up, 42 (10%) had haemodynamically relevant symp- either partially or completely. Usually the ECG shows a short- 7
o
toms including syncope, presyncope, light-headedness, chest ened PR interval <120 ms and a delta wave. The length of the n
discomfort, dyspnoea or visual changes, with an additional 21 PR interval depends on the location of the accessory pathway 13
(5%) experiencing recurrent sustained SVT (defined as >10 min, and the conduction properties of the accessory pathway and N
o
without haemodynamic symptoms).40 Mean follow-up in this AV node. In contrast to simple pre-excitation on the ECG, v
e
study was 11.4±9.0 years, and median follow-up was 7.9 years Wolff-Parkinson-White (WPW) syndrome requires evidence of m
b
with a range from 1 to 35 years. Individuals with asymptomatic tachyarrhythmia or symptoms of palpitations for diagnosis. e
SVT often remained symptom-free for many years; however, of Individuals with fast conduction over the accessory pathway, r 2
0
those presenting with one or more episodes of sustained SVT, multiple pathways43 or retrograde conduction over the acces- 18
recurrence was 1–2% per annum.41 sory pathway can be regarded as high-risk individuals (figure 2). . D
o
Individuals with sustained SVT are usually unfit for aircrew Fast antegrade conduction over the accessory pathway may lead w
duties. If asymptomatic, and in those with non-sustained SVT, a to ventricular fibrillation (VF) and SCD in cases of AF, while nlo
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Figure 2 Risks possibly associated with an accessory pathway. (A) During sinus rhythm there is conduction via the atrioventricular (AV) node and te
c
accessory pathway. The delta wave in the ECG represents the ventricular pre-excitation caused by the conduction via the accessory pathway. The size te
d
of the delta wave and the PR interval depend on the location of the accessory pathway and the conduction properties of the AV node and accessory b
pathway. (B) A retrograde conduction of the accessory pathway bears the risk of an orthodromic AV re-entrant tachycardia with antegrade conduction y c
via the AV node and retrograde conduction via the accessory pathway. (C) During atrial fibrillation there is a risk of a fast conduction via the accessory op
y
pathway to the ventricles depending on the conduction properties of the accessory pathway. As most accessory pathways have no decremental rig
conduction in contrast to the AV node, the conduction via the accessory pathway can be much faster than via the AV node. This can lead to ventricular h
t.
fibrillation and sudden cardiac death.
Guettler N, et al. Heart 2019;105:s38–s49. doi:10.1136/heartjnl-2018-313057 s43
Standards
Investigations are required to confirm or exclude underlying
Table 6 Recommendations for supraventricular tachycardia H
causes (echocardiography, laboratory tests, chest X-ray, and a e
RAeirccroemwm weitnhd sautsiotaninsed supraventricular tachycardia or Not risTk-hfea citnovre dsteigpaetniodnen atn edx mamaninaagteiomne ntot oefx cAlFud ine CaiArcDre)w. requires a art: firs
symptomatic non-sustained supraventricular tachycardia are unfit recommended comprehensive and integrated approach as it may have a cardiac t p
for aircrew duties and require further investigation. or non-cardiac aetiology. AF can be associated with valvular u
b
In asymptomatic pre-excitation risk stratification for the exclusion Recommended heart disease, CAD, cardiomyopathies, hypertension, hyper- lis
of fast antegrade conduction, multiple pathways, or retrograde thyroidism, and respiratory diseases. Other potential causative he
conduction is required. These individuals should all be referred for d
invasive EP assessment and possible catheter ablation. oalrc otrhigogl eor rf accatoffresi ninec leuxdcee sesl,e cdtrroulgy tein dtaiskoer d(einrsc,l usdepinsgis , msmetoakbionlgic, as 1
supplements), excessive physical activity, fatigue, and exhaus- 0
.1
tion. In cases where there is a clear causative aetiology for AF, 1
3
retrograde conduction over the accessory pathway may allow the underlying disease guides treatment. 6
for AV re-entrant tachycardia.44 Fast antegrade conduction can AF should be managed in accordance with international guide- /he
be Idne tperremviionueds bayir corbeswer vsitnugd iaens ,R pRr ein-etxecrvitaalt i<on2 5w0mass idduernitnigfi eAdF .i4n3 loinr ems.a50in 5t1a iwn1 Psionsussib rleh ystihdme eoffre cttos coof nmtreodl icvaetniotrnic uuslaerd rtaot er emstaokree artjnl-2
0.25–1% of healthy subjects, but only a very small proportion AF a difficult condition to manage in aircrew. Flecainide and 0
1
(<2%) of these aircrew had any documented arrhythmia.45 46 propafenone (Vaughan-Williams class IC) as well as amiodarone, 8
In the latter study, with follow-up for over two decades, 15% of dronedarone, and sotalol (Vaughan-Williams class III) are all -31
3
patients with pre-excitation developed new symptoms including incompatible with unrestricted flying due to their side effect 0
5
new tachyarrhythmias, with one case of SCD. As the incidence profile. β-blockers are often used for rate control; however, 7
o
of AF increases with age, the risk of WPW also increases due to given the negative chronotropic effects and blunted blood pres- n
the risk of fast antegrade conduction via the accessory pathway. sure response to these agents they are not recommended for 13
In a recently published study from the USAF ECG library, 638 aircrew flying high performance aircraft. N
o
aircrew with pre-excitation (0.3% of all aircrew) were identi- Given the adverse side effect profile of these agents, AF cath- v
e
fied over a 68 year period.47 Aircrew who developed high risk eter ablation is increasingly recommended as a first line interven- m
b
features (defined as symptoms, arrhythmia or ablation of a high- tion in aircrew, as with the general population.51 Isolation of the e
risk pathway) were compared with those who remained asymp- pulmonary vein ostia within the left atrium may be achieved by r 2
0
tomatic. Sixty-four of 638 individuals (10%) progressed to the radiofrequency, cryotherapy or laser-based procedures. In PAF 18
combined endpoint of SCD, arrhythmia and/or ablation of a success rates >80% can be achieved, with cryo-balloon ablation . D
high-risk pathway with average follow-up of 10.5 years. There non-inferior compared with radiofrequency ablation.52 53 Unlike ow
were two SCDs (0.3%). Annual risk of possible sudden incapac- PAF, the long-term success rate in patients with persistent AF nlo
itation was 0.95% and of SCD 0.03%. Interestingly, those that is only 40–60% after a single ablation,54 and in many cases a a
d
progressed were significantly younger at presentation. second or third intervention is necessary. ed
Ablation for pre-excitation/WPW syndrome is deemed cura- When assessing aircrew that have undergone AF ablation, the fro
tive in almost 100% of cases, and has a very low risk of compli- observation period to determine the success of the procedure m
ctdhaoetci ouAnmVse , nnpotaedrdtei .ci nuF loaar r1 lty2h feloesrea darc eEcaeCssoGsno srs,yh aoplula ltadhi wrbcear yerwse lf oewrcriatethde d pt orfue a-rentxh eceilrte afcrttioroomn- spahrerorhiuoyldtdh’ mloafisa t3 sa rmte gloeanartsdhtl se6,s dsm uoorfi nnthtghe sw a; hbtlihacihtsi otinhn ecsl uuacbdcleaests isao,n na niintdsi etailnaf l m a‘dbadlyai tncikoauinnsagel http://he
petheyrs aioblloagtiiostn f(otar bilnev 6a)s.i4v4e EP testing and consideration for cath- obAsesr wvaittiho nn otnim-aei rocfr eawt ,l eaanstti c3o afugrutlhaetiro mn oshnothusl.d be determined by art.b
m
the CHA2DS2VASc score. Most aircrew have a CHA2DS2VASc j.c
Atrial fibrillation score of 0 and do not need anticoagulation. If anticoagulation is o
m
AF is the most common type of cardiac arrhythmia seen in needed, it can be done with vitamin K antagonists or direct oral o/
aircrew. A study of UK aircrew found asymptomatic AF in 0.3% anticoagulants (DOACS). For military aircrew, permanent anti- n
of all aircrew during routine ECG screening,48 many of whom coagulation is often, but not universally, disqualifying; however, Fe
b
were returned to flying in a limited capacity.49 civil regulations are usually less restrictive. ru
a
Idiopathic AF (without an underlying aetiology) may rarely Return to aircrew duties requires a detailed cardiovascular ry
occur as a single episode, is often paroxysmal (PAF) (≤7 days) assessment and consideration of the aircrew role (table 7). 6
but may be persistent (>7 days) or permanent (no attempts/ Return to unrestricted flying is usually only possible after a single , 2
0
failed attempts to restore sinus rhythm).50 In most cases, AF episode of AF without underlying disease, but with an identified 2
3
encountered in the military aircrew population is paroxysmal, b
y
idiopathic and converts either spontaneously or by medical g
u
intervention within 24 hours. A single episode occasionally has a Table 7 Recommendations for atrial fibrillation e
s
clearly identifiable cause, such as acute alcohol excess (so-called Recommendations t. P
‘hoAleidroaym heedaicrta ls ycnodnrcoemrnes’ ) ionrc lsuudpep lpeamlpeintat tuiosen.s, dizziness, short- Aircrew with atrial fibrillation (AF) are initially unfit for flying and Not rote
require a thorough evaluation for underlying cardiological and recommended c
ness of breath, presyncope, syncope, exercise intolerance, and non-cardiological diseases, including the need for anticoagulation. te
d
haemodynamic instability. The loss of atrial contribution to For pilots, return to unrestricted flight duties is possible after a Recommended b
cardiac output, loss of atrioventricular synchrony, and the rapid single episode of AF without underlying disease and a clearly y c
ventricular response during an episode may impair cardiac identified trigger factor. All other aircrew may be considered op
y
performance, especially during exertion, and can be acutely for a return to restricted aircrew duties (no single seat, no high rig
distracting or incapacitating. For these reasons aircrew diag- performance) depending on their symptoms and their rhythm h
nosed with AF are initially to be made unfit for aircrew duties. stability. t.
s44 Guettler N, et al. Heart 2019;105:s38–s49. doi:10.1136/heartjnl-2018-313057
Standards
Table 8 Recommendations for atrial flutter Table 9 Recommendations for ventricular ectopy H
e
RAeirccroemwm weitnhd aattriioanl flsutter are initially unfit for flying and require Not RIf etchoe mbumrdeennd oaft ivoennstricular ectopy (VE) exceeds 1%, further Recommended art: firs
a thorough evaluation for underlying cardiological and non- recommended investigation should be considered; if >2% this is recommended t p
cardiological diseases, including the need for anticoagulation. and cardiac MRI should be considered to exclude cardiomyopathy. u
Return to unrestricted aircrew duties without appropriate therapy Under age 40, a coronary CT should be considered; over age 40, it blis
may be possible but should be limited to those with one single is recommended. Restricted flying during evaluation is possible. h
e
episode, no underlying disease, and identifiable trigger factor. In the case of a VE burden >5%, additional yearly follow-ups Recommended d
are recommended. Unrestricted flying is usually possible, if as
asymptomatic. 1
0
trigger factor. In all other cases, restricted flying in low-perfor- A VE burden >7.5% usually requires restrictions to multicrew Recommended .11
operations and low performance flying; above 10% consideration 3
mpearniocde oafi r3c–ra6f tm monatyh sb dee ppeonssdiibnleg oanft eflry ian gm diuntiimesu, mw itohb esexrtveantsiiovne of further restrictions is recommended. 6/h
e
ircneisvsete EsatCnigdGa t)di.ou Inrni ntbogo techof fpnoafirrtro m(xl oyssntmagb-adlle uA rsFaint aiuonsnd r pHheyortslhtimestre onmrto ArnaFit,te or ercicnougnr,tr reeonxlc eears-t w30it sh peexreiorcdi sdeu EriCngG ,e xife rtchisee ,n ufumrtbheerr oinf vPeVstCigsa teixocne ewdist h1 e0c%ho icna ra- artjnl-20
1
may occur years after ablation therapy, and as a result, most diogram and Holter is also recommended. 8
licensing authorities do not allow a return to single seat flying The ectopy burden on the 24 hour Holter determines the -31
operations or high-performance flying. In severe situations that requirement for further specialist work-up. If the VE burden 30
5
require surgical ablation, mostly performed as a concomitant exceeds 1% further investigation should be considered; if >2%, 7
procedure to coronary bypass or valve surgery,55 or a left atrial or complex forms are prevalent, further investigation is recom- on
appendage exclusion with internal devices because of contraindi- mended to exclude cardiomyopathy. Recent evidence suggests 1
3
cation to anticoagulation, aircrew are likely to be unfit for flying. that cardiac MRI may be particularly useful in this scenario.60 N
o
If aircrew with frequent ectopy burden are under the age of v
e
Atrial flutter 40 years at presentation, a CT coronary angiogram should be m
b
Atrial flutter may coexist with AF or occur in isolation. In most considered; if over age 40, it is recommended. e
cases atrial flutter is caused by similar underlying pathology to Aircrew may often be able to continue to fly in a restricted r 2
0
those causing AF with similar aeromedical concerns. An addi- (dual-pilot) role during evaluation. If the VE burden is <2%, 1
8
tional concern in atrial flutter is the potential for 1:1 AV conduc- with no complex forms and no evidence of sustained ventricular . D
tion resulting in extreme tachycardia and acute incapacitation. tachycardia (VT) or complex ectopy, no further testing is usually o
w
Aircrew with atrial flutter require thorough cardiac and non-car- required, and the results are usually aeromedically acceptable. In n
lo
diac evaluation (table 8). aircrew with higher ectopy burden (>5%), yearly follow-up with a
d
Typical atrial flutter is a right atrial macro-re-entrant tachy- exercise ECG, echocardiography and Holter is recommended e
d
cardia with the re-entrant circuit passing through the cavo-tri- for the early detection of tachycardia related cardiomyopathy. fro
cuspid isthmus. Antiarrhythmic medication is usually only Most aircrew can continue to fly in an unrestricted capacity. In m
moderately effective and not appropriate for aircrew. Catheter those with a VE burden >7.5% many licensing authorities would h
athbela tisiothnm isu su spuaatlhlyw tahye, afinrdst hlianse stuhcecreaspsy ,r aatbelsa t>in9g0 a% li nwei ttho ubplo ctok caoirncsriadfet;r hreoswtreicvteirn, gt haeirrcer eiws ntoo mcounlsteicnrseuws aonnd alno wu pppeerrf olrimmiatn coef ttp://h
e
2 years follow-up.56 Some studies suggest a moderate rate of ectopy that requires disqualification, although if >10% and a
subsequent AF, following flutter ablation,57 and recurrence can not suppressed by exercise, many licensing authorities would rt.b
m
sometimes occur years after the ablation, with the highest inci- consider additional restrictions (table 9). j.c
dence in those with atypical flutter (non-isthmus-dependent) and VE ablation has emerged as a state of the art treatment that o
m
associated structural heart disease. many believe can effectively cure VE, or at least reduce VE o/
Due to the arrhythmogenic +G environment, single seat and burden significantly, as the origin of aberrant ventricular elec- n
flying high performance aircraft arze not generally recommended trical activity is usually well localised.61It should be considered in Fe
b
following flutter ablation. In selected cases, consideration of a symptomatic patients, PVC-induced ventricular tachyarrhythmia ru
diagnostic EP study to reconfirm bidirectional isthmus block or PVC-mediated cardiomyopathy.62While it may be possible to a
ry
would be recommended if considering a more lenient approach. return aircrew to multi-crew, low performance flying, further 6
long-term evidence is required before unrestricted aircrew priv- , 2
0
Ventricular ectopy/premature ventricular complexes (VE/PVCs) ileges can be considered. 2
3
VE/PVCs are a common finding in aircrew and have been b
y
reported on 12-lead ECG in about 0.8% of aircrew compared Accelerated idioventricular rhythm g
with 2.0–7.0% of civilian populations.58 Aeromedical concerns In AV node dysfunction, idioventricular escape rhythms (IVR) ue
s
related to VE/PVCs include haemodynamic compromise, partic- may be seen, usually with a heart rate between 30 and 40 beats t. P
ularly during +Gz, and possible underlying heart disease. per min (bpm), and IVR is defined by the presence of three or ro
An additional concern is the development of tachycardia-re- more monomorphic ventricular beats. If the heart rate of an IVR te
c
lated cardiomyopathy following recent evidence that large exceeds the heart rate of sinus rhythm, this is known as an accel- te
d
numbers of PVCs (>10% burden) can cause cardiomyopathy and erated idioventricular rhythm (AIVR). b
should be treated by antiarrhythmic drugs or catheter ablation.59 AIVR may be a benign arrhythmia, usually seen in the young,63 64 y c
For aircrew with two or more PVCs or complex ectopy on a but can manifest in several different clinical scenarios.65 AIVR op
y
reochuoticnaer dEiCoGgr,a fpuhryth aenrd a sesxeessrmciseen tE wCiGth i as r2e4c hoomumr eHnodletder. mSuopnpirtoesr-, otocnceu6r6s adnude i s tcoo manm oinnclrye oabsesder vveadg ainl aatnhdle tdeesc arnedas aetdh lseytimc paiartchreetwic. righ
t.
sion of ectopy with exercise is reassuring. In aircrew assessment However, AIVR may also be associated with underlying cardiac
Guettler N, et al. Heart 2019;105:s38–s49. doi:10.1136/heartjnl-2018-313057 s45
Standards
disease, including cardiomyopathy67 68 and ischaemic heart
Table 10 Recommendations for broad complex arrhythmias H
disease.69 It is also seen in pregnancy.70 e
forIef AbIeV rRu liesd d eotuetc.t eIndv iens taiigractrieown, munadye irnlycilnugd ed itsheea sues suhaol ugladm thuet roef- RAeirccroemwm weitnhd aactcioelnesrated idioventricular rhythm should be Recommended art: firs
echocardiography, exercise ECG and Holter monitoring, while evaluated for an underlying disease. If an underlying cause can be t p
cardiac MRI may be appropriate in some cases. If no underlying excluded, a return to unrestricted aircrew duties including flying u
aetiology is found, therapeutic intervention and flying restric- is possible. blis
tions are not indicated. Aircrew with ventricular tachycardia (VT) are initially unfit for Recommended he
flying and must be evaluated for underlying disease. Return to d
restricted aircrew duties may be possible, if there is no underlying as
Non-sustained and sustained ventricular tachycardia disease, the VT is asymptomatic, the VT duration is no longer than 1
0
VT is defined as three or more consecutive premature ventricular 11 beats, and if there are no more than four runs within any 24 .1
hour period. 1
contractions at a heart rate of more than 100 bpm. Non-sus- 3
tained ventricular tachycardia (NSVT) is usually defined as VT Aircrew who have undergone catheter ablation are initially unfit Recommended 6/h
for flying for a certain observation period. Return to aircrew duties e
with a duration <30 s. VT can be divided into idiopathic or a
secondary to conditions such as structural, coronary or heart mobasye rbvea tpioonss aibnlde arifstke-ra as speesrsimode notf poobsste arvbalatitoionn. T whiisll ldeenpgethn do fo n the rtjn
muscle disease, or ion channelopathies. Determining if NSVT is treated arrhythmia. l-2
0
idiopathic can be challenging; however, the presence of frequent 1
8
VE during recovery directly after exercise appears to be even -3
more predictive of an increased risk of death than frequent should be performed in specialist centres using international 13
VE during exercise.71 guidelines78 and can be very challenging.79 Crucial factors 05
7
From an aeromedical perspective, NSVT for nearly 30 s would include medical and family history and genetic testing. High o
potentially be catastrophic and as a result the threshold for risk patients usually need implantable cardioverter-defibrillator n 1
defining (significant) VT in aviation cardiology is stricter than (ICD) implantation to prevent SCD and are permanently unfit 3 N
civilian guidelines. In a 30 year review of 193 aviators evaluated for flying. While ICDs may prevent SCD they do not necessarily o
v
by the USAF for non-sustained VT, the maximum predicted prevent the arrhythmia and any shock delivered would be poten- em
event rate for idiopathic non-sustained VT was 0.3% per year.72 tially distracting or incapacitating. However, after careful risk b
e
The longest VT duration was 11 beats or less in 98% of the stratification, restricted flying might be possible in asymptom- r 2
cohort and the number of VT runs per evaluation was four runs atic, lower risk individuals, on a case-by-case basis. 01
8
in 90% of the cohort, establishing these two limits as thresholds . D
used by many air forces. Brugada syndrome o
Aeromedical concerns include the presence of haemodynamic BrS is diagnosed in the presence of typical ECG changes. There wn
symptoms such as pre-syncope or syncope and chest pain, and are three recognised BrS morphology types, with type 1 being lo
a
the risk of acute incapacitation or SCD and distraction in the associated with the highest risk of arrhythmia and SCD. Type de
cstrriuticctaul raplh oars ecsa rodfi aflc igdhiste. asAei rocrr eswym wptiothm ss iagrnei fiucnafintt fuonr daeirrlcyrienwg 1ti oBnr Sw hitahs ctlyapsesi c1 c hmaonrgpehs oilno gleya d≥ V2 1m amnd i nV 2≥ (S1T le-saedg mamenotn egl etvhae- d fro
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duItdieiso.pathic VT usually originates from one of the outflow roirg hfot uprrthec ionrtdeiraclo sletaald ss p(aVce1,7 8V) 2t hpaots imtiaoyn eodc ciunr tshpeo nsteacnoenodu,s ltyh, irodr http
tracts, more commonly the right ventricular outflow tract after provocative drug test with class I antiarrhythmic drugs such ://h
(RVOT) than the left (LVOT). RVOT tachycardias have a typical as ajmaline or flecainide. The highest risk patients may present ea
morphology with inferior axis and LBBB. The usual treatment with typical ECG changes and have survived cardiac arrest or rt.b
options for symptomatic NSVT, such as β-blockers and calcium syncope. Symptomatic patients are usually treated with an ICD m
channel blockers, are incompatible with many flying roles, and and are unfit for flying. j.c
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the fact that RVOT tachycardia is amenable to ablation, with In asymptomatic individuals spontaneous type 1 BrS ECG is m
high success rates, means that ablation should be considered as a associated with the highest likelihood of clinical sequelae. Other o/
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first-line therapy.73 74 Even in LVOT tachycardia, where ablation predictors for an increased risk are male gender, family history F
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is usually considered only if antiarrhythmic drug therapy is not of SCD, and spontaneous AF. There is controversy about the b
effective or not tolerated because of side effects, ablation should value of an EP study for inducibility of ventricular arrhythmia. rua
be considered first line for aircrew. After successful catheter abla- Brugada patients should avoid certain drugs ( brugadadrugs. ry
6
tion and a period of observation, return to aircrew duties may org) and excessive alcohol consumption, and they should reduce , 2
be considered (table 10). After a certain arrhythmia-free period, fever immediately, for example, with paracetamol. New risk 0
2
return to unrestricted flying may be possible after a case-by-case markers like a fragmented QRS complex and a ventricular effec- 3
b
decision. tive refractory period <200 ms are under investigation. y
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Individuals with primary or secondary VF are permanently For aeromedical assessment differentiation between Brugada u
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unfit for aircrew duties. syndrome and Brugada pattern is important. Patients with s
Brugada type 1 syndrome may develop ventricular arrhythmia t. P
ro
Inherited arrhythmogenic conditions (channelopathies) te
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Aircrew with inherited arrhythmogenic disorders, including long Table 11 Recommendations for channelopathies te
d
QT syndrome (LQTS) or Brugada syndrome (BrS), are usually b
unfit for flying (table 11).75 Channelopathies are usually caused Recommendations y c
by transmembrane ion channel or protein mutations involved in Individuals with inherited arrhythmogenic conditions (channelopathies) Consider op
intracellular calcium handling. astrrea tuisfiucaaltliyo nu,n afiitr cfroerw a idrcurteiews dmuitgiehst. bHeo pwoesvseibr,l ea fitne ra csaymrepfutol mrisakt ic, lower yrig
Channelopathies are rare, but LQTS and BrS cases predom- h
inate in the aviation medicine literature.75–77 Risk stratification risk individuals, on a case-by-case basis. t.
s46 Guettler N, et al. Heart 2019;105:s38–s49. doi:10.1136/heartjnl-2018-313057
Standards
at a rate of 7.7% per year; patients with asymptomatic Brugada consider all criteria for the aeromedical assessment, including
H
type 1 pattern have a rate of 2.3% events per year.80 Pilots that the age of diagnosis, the type of LQTS (mutation identified, e
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hay eahavries. 8tB1o rHruyo gowafde avV etFry ,p oBerr u2sg ysanydcnaod ptryeop meh ae2v E(es Ca1dG.d3 lp9ea%btat eccrkan lE cwuCiltGaht oefidun td esviynemgnspt)st oapmnedrs emmxeopdneiiccttoaelrd itn rgcei)ar,t camunmedns ttth)a,ne tctheyesp eda nuordf a attiirrocingr gaaeftnr sad n osdft aabairrilcrirhteyyw toh.fm QiaTs,c p(Hososilbteler rt: first p
have <0.5% events per year, with an equally low event rate for u
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individuals with Brugada type 3 pattern. As ECG morphology CONCLUSION/SUMMARY lis
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can change, at least three serial ECGs should be done not less Electrical abnormalities are a common finding in aircrew. In e
d
than 24 hours apart. All individuals with type 2 pattern should a young fit population, many abnormal ECG findings may be a
s
be challenged with sodium channel blockers. Genetic testing for considered benign and associated with high vagal tone. However, 1
mutations in the SCN5A gene are of limited use, because there in those cases where a significant underlying aetiology is plau- 0.1
are more than 80 known mutations of this gene, and not all these sible, extensive investigation is often required and, where appro- 1
3
gene carriers are at significant risk for clinical disease.75 priate, should include review by an electrophysiologist. The 6/h
Meanwhile, the arrhythmogenic substrate of Brugada decision regarding restriction of flying activity will be dependent e
a
syndrome could be localised at the anterior RVOT epicar- on several factors including the underlying arrhythmia, associ- rtjn
dium.82 83 Catheter ablation of this epicardial substrate is now ated pathology, risk of incapacitation and/or distraction, the type l-2
possible in many patients with symptomatic Brugada syndrome, of aircraft operated, and the specific flight or mission criticality 0
1
preventing spontaneous VT/VF episodes and leading to normal- of the role performed by the individual aircrew (online supple- 8-3
isation of the Brugada pattern. It is hoped that this new thera- mentary table 12). 1
3
peutic option may ‘cure’ the subset of patients with symptomatic 0
Brugada syndrome and without overlapping syndrome—that is, Contributors All authors were part of the NATO aviation cardiology WG and all 57
contributed to the design and writing of this article. o
combined Brugada syndrome and early repolarization syndromes, n
Funding Produced with support from NATO CSO and HFM-251 Partner Nations. 1
without the need for ICD implantation. To test this hypothesis 3
the prospective, multicentre, randomised, non-blinded BRAVE Competing interests None declared. N
o
study (Ablation in Brugada Syndrome for the Prevention of VF Patient consent Not required. ve
m
Episodes) was recently established. Provenance and peer review Commissioned; externally peer reviewed. b
ICIDn simumplmanatray,t iionnd iovrid iunaclrse wasiitnhg slyy mcaptthoemtesr a areb luastuioanll ya ntrde astheodu bldy OCrpeeantiv aec Ccoemssm oThniss Aist tarinb uotpioenn Nacocne sCso amrtmiceler cdiaisl t(rCibCu tBeYd- NinC a 4cc.0o)r dliacnencese w, withh itchhe er 20
1
be grounded. Aircrew with Brugada type 2 or 3 ECG pattern permits others to distribute, remix, adapt, build upon this work non-commercially, 8
without symptoms, with a negative family history and a negative and license their derivative works on different terms, provided the original work is . D
drug challenge, may be assessed fit for flying with limitations76 properly cited, appropriate credit is given, any changes made indicated, and the use ow
is non-commercial. See: http:// creativecommons.o rg/ licenses/b y- nc/4 . 0/. n
and regular follow-up is mandatory. All individuals with spon- lo
taneous type 1 ECG, type 1 ECG after challenge with sodium REFERENCES ade
channel blockers, a history of ventricular arrhythmias, syncope, d
or survived cardiac arrest, and a positive family history should be 1 Mdeaanthtz iaanrid L i,n Sctaypliaacdiitsa tCio, nK oouf rptiidlootus.- PHaippapdoeklria Cti,a e 2t 0a0l.8 A;1rr2h(yStuhpmpila 1s,) :s5u3d–d8e.n cardiac fro
assessed as unfit for flying. 2 Epstein A, Miles W, Benditt DG, et al. Personal and public safety issues related to m
arercrhoymthmmeinads atthioant sm. Cayir cauffleactito cno 1n9sc9io6u;9s4n:e1s1s:4 i7m–p6l6ic.ations for regulation and physician http
Long QT syndrome 3 Coumel P, Leenhardt A. Mental activity, adrenergic modulation, and cardiac ://h
arrhythmias in patients with heart disease. Circulation 1991;83:158–70. e
LQTS can be diagnosed in the absence of a secondary cause for a
QT prolongation, in particular drugs and ionic disorders, and/or 4 CEloeuctmroepl hP.y sCioarl d1i9ac9 3a;r4rh:3y3th8m–i5a5s. and the autonomic nervous system. J Cardiovasc rt.bm
in the presence of an unequivocally pathogenic mutation in one 5 Fischer U. Der kreislauf unter beschleunigung. Röntgenaufnahmen beim affen. j.c
of the LQTS genes. Additionally, the presence of a QT interval Luftfahrtmedizin. Julius Springer Verlag 1937;2:1. o
6 Hanada R, Hisada T, Tsujimoto T, et al. Arrhythmias observed during high-G training: m
corrected for heart rate (using Bazett’s formula or Hodges’ proposed training safety criterion. Aviat Space Environ Med 2004;75:688–91. o/
formula) of QTc ≥500 ms in repeated 12-lead ECGs, and in n
7 Pison L, Crijns HJ. How effective is ablation therapy for cardiac arrhythmias? Clin Pract F
the absence of a secondary cause for QT prolongation, is diag- 2013;10:177–87. e
b
nostic for LQTS. Finally, LQTS can be diagnosed using a clinical 8 Liao JN, Chao TF, Tuan TC, et al. Long-term outcome in patients receiving permanent ru
rinisgLks Q,s acTonSrd e rf aitshmka itli ynin hcaiosstyropmroypr.t7ao8t em8s4 astpice cpifiacti eEnCtsG dfienpdeinndgss , ocnli ntihcea l tfiynpdes- 9 Bppimaarupccneilnamngnea.tr akM Mteiero, d niOmi.c lPipsncrleaoh nge2twn0ao1stisk6otiin; c9M f5iom,: reGp 4aeo6tirrb6tieoa8lnv .Aecne, teortifc auglle.a nLro dbnelrgo -catkne:dr cm ob masusperavlirinviseao lp naa fottiefe rVn pDt aDcch eaamnradac ktDeeDrr iDst ics. ary 6, 20
of genetic mutations and degree of mutation dysfunction. If Eur Heart J 2004;25:88–95. 2
3
measuring just the QT interval, patients with a QTc >500 ms 10 Crouse LJ, Harbrecht JJ, Vacek JL, et al. Exercise echocardiography as a screening test b
can be regarded as high risk, and those with a QTc >600 ms as for coronary artery disease and correlation with coronary arteriography. Am J Cardiol y g
1991;67:1213–8. u
very high risk. The presence of overt T-wave alternans, especially 11 Mowatt G, Cook JA, Hillis GS, et al. 64-Slice computed tomography angiography in es
despite avoidance of drugs with QT prolongation and β-blocker the diagnosis and assessment of coronary artery disease: systematic review and meta- t. P
treatment, is a direct sign of electrical instability and calls for analysis. Heart 2008;94:1386–93. ro
preventive measures.78 12 Budoff MJ, Dowe D, Jollis JG, et al. Diagnostic performance of 64-multidetector te
row coronary computed tomographic angiography for evaluation of coronary artery c
Among genotyped patients, LQT1 males, who are asymptom- stenosis in individuals without known coronary artery disease: results from the ted
atic at a young age, are at low risk of becoming symptomatic prospective multicenter ACCURACY (Assessment by Coronary Computed Tomographic b
later in life, while females, especially LQT2 females, remain at Angiography of Individuals Undergoing Invasive Coronary Angiography) trial. J Am y c
risk even after age 40. Coll Cardiol 2008;52:1724–32. o
p
In aircrew, further investigation should be recommended above 13 AGcehrmenabna Rcha dSi,o Bloagrky hSaoucsieetny J(,D BReGe)r, Mth,e e Gt aelr.m [Cano nCsaerndsiuasc rSeoccoimetmy (eDnGdaKt)i oannsd otfh eth Ge erman yrig
fla yQinTgc. Fcuotr- oasffy mofp t4o7m0a mtisc. aSiyrcmrepwto, ma actaisce -inbdy-icvaidseu adles caisrieo nu nsfihto ufoldr Stoomcioetgyr afoprh yP eadnida tmrica gCnaerdtiico lroegsoy n(DanGcPeK i)m oang itnhge] .u Rseo foof 2ca0r1d2ia;1c8 i4m:a3g4i5n–g6 w8i.th computed ht.
Guettler N, et al. Heart 2019;105:s38–s49. doi:10.1136/heartjnl-2018-313057 s47