1. 16.1 Introduction
Electrophysiological studies are instrumental
methods enabling the registration of electric endo-
cavitary cardiac signals relative to the various
phases of the cardiac cycle. Registration is carried
out through unipolar or bipolar electrocatheters,
which also allow electrical stimulation of the heart.
Stimulation of the cardiac chambers is an ex-
tremely useful method for accurately measuring
intervals and/or pauses and for reproducing in the
laboratory arrhythmias that patients may experi-
ence clinically (arrhythmic inducibility test). Elec-
trophysiological evaluations can be performed via
the transesophageal or endocavitary pathways.All
the material used both for endocavitary and trans-
esophageal electrophysiological studies is sterile
and for single use.
A transesophageal electrophysiological study
is conducted by inserting an electrocatheter
through the nasal cavity and into the esophagus.
The posterior wall of the left atrium is in strict
proximity with the esophagus and therefore with
the electrocatheter it is possible to register the
signals emanating from the left atrium, as well as
performing programmed atrial stimulations. The
theoretical advantages of this method are reduced
invasiveness compared to an endocavitary study
and the possibility of registrations and/or stipula-
tions even during physical exertion (bed-ergome-
ter) [1]. Limits include the scarcity of electrical in-
formation (registration only of atrial signals) com-
pared to a complete endocavitary study, the possi-
bility of stimulating only the atrial cavity and not
the ventricular cavity, potentially low patient tol-
erability (painful stimulations), the need to con-
sider an eventual ablative intervention in another
context, which, in case of an endocavitary study,
can be carried out at the same time.
An endocavitary electrophysiological study is
conducted by inserting electrocatheters (gener-
ally between one and four) directly into the cardiac
cavities. The procedure is carried out with local
anesthesia and the catheters are inserted through
venous and/or, more rarely, arterial vascular access
points. The insertion of the catheters into the vas-
cular system towards the heart and, subsequently,
their positioning in the various anatomical seg-
ments of the heart, is not painful and is performed
under a fluoroscopic guide (Fig. 16.1). The elec-
trocatheters (see also Chapter 17) are positioned in
certain anatomically determined areas of the heart
(for example the lateral wall of the right atrium,
bundle of His, coronary sinus, right ventricle
apex). The registration of electric signals in these
areas enables the accurate reconstruction of the se-
quence of endocavitary activation of a particular
cardiac rhythm. A precise endocavitary electro-
gram of the heartbeat is therefore reconstructed al-
lowing accurate diagnosis of the electrophysiolog-
ical genesis of cardiac arrhythmias. Through the
electrocatheters, as previously mentioned, pro-
grammed stimulations of the cardiac cavities can
be carried out. These enable further measurements
of intervals and/or pauses, artificial initiation of
cardiac arrhythmias (Fig. 16.2) leading to possible
clinical arrhythmic episodes in a patient.
Electrophysiological Studies in Athletes
Luigi Sciarra, Antonella Sette, Annamaria Martino,
Alessandro Fagagnini, Lucia de Luca, Ermenegildo de Ruvo,
Claudia Tota, Marco Rebecchi, Fabio Sperandii,
Emanuele Guerra, Gennaro Alfano, Fabrizio Guarracini,
Fabio Pigozzi and Leonardo Calò
16
185M. Fioranelli and G. Frajese (eds.), Sports Cardiology,
DOI: 10.1007/978-88-470-2775-6_16, © Springer-Verlag Italia 2012
CARDIAC ARRHYTHMIAS
L. Calò ( )
Electrophysiology Department
Policlinico Casilino, Rome, Italy

2. 16.2 Clinical Evaluation
of Arrhythmia in Patients:
General Principles
Sporadic arrhythmias of benign prognostic signif-
icance can be present even in perfectly normal
subjects. The athlete can also manifest rhythm dis-
orders connected to the intensified vagal tone
caused by physical exercise or by adrenergic hyper-
tone during intense physical activity. Establishing
a limit between normality and disease is not always
simple. For this reason the clinical evaluation of ar-
rhythmia in an athlete needs to be accurate and
takes advantage of opportune instrumental diag-
nostic principals, from the most simple to the most
complex, which may become necessary.
As specified in the COCIS protocol (Organiza-
tional Cardiac Committee for Suitability to Prac-
tice Sport) in 2009 [2], the connection of suitabil-
ity for competitive sport activity has to include:
• suspected or demonstrated arrhythmias;
• heart diseases that are predisposing factors for
malign arrhythmias;
• arrhythmias treated with transcatheter ablation,
pacemaker implantation or defibrillators.
The clinical evaluation of arrhythmia in an ath-
lete has to be based on three levels for an adequate
identification of competitive suitability. Accurate
gathering of the patient’s medical history, an ob-
jective examination, and a 12-lead electrocardio-
gram at rest and after a step test are the first level
of evaluation during a medical examination to es-
tablish competitive suitability. The second level of
evaluation must also include non-invasive assess-
ments, such as mono- and bi-dimensional echocar-
diography studies and color-Doppler analysis, a
maximum ergometric test, and the 24-hour Holter
monitor. The latter must include a workout session
during registration, in the absence of any con-
traindications, and a nycthemeral cycle. If neces-
L. Sciarra et al.186
terQuadripolar cathe
on the His bundle
erDecapolar cathete
nusin the coronary sin
terQuadripolar cathe
cularfor the interventric
septum
eterTwentypolar cathe
on the tricuspidal
annulus
Fig. 16.1 Example of
fluoroscopic visualization
of electrocatheters
positioned in the heart
during an
electrophysiological
endocavitary study (lateral
anterior oblique view)
Fig. 16.2 Example of ventricular tachycardia induction us-
ing programmed ventricular stimulation. The pacing
catheter is positioned in the right ventricular apex and the
recorded signal is identified by RV. From this site, pro-
grammed ventricular stimulation has been performed, con-
sisting of the paced train of extrastimulus (S1) and two pre-
mature beats (S2 and S3) that induced the rapid monomor-
phic ventricular tachycardia with initial hemodynamic com-
promise. It has been promptly interrupted by using ventric-
ular stimulation in overdrive, i.e. the frequency of ventricu-
lar pacing is higher than the frequency of tachycardia

3. sary during this level, biohumoral examinations
can be included (hemochromocytometric tests,
thyroid hormone tests, and possibly infectiology
tests and other indicated tests).
Based on the type of arrhythmia documented
and on the symptoms reported by the athlete, it
could be necessary to pass to a third level of eval-
uation that includes invasive and non-invasive
studies. Third-level tests are: the tilt test, pharma-
cological tests (atropine, isoproterenol, flecainide
etc.), the investigation of ventricular late potentials
with the signal averaging method, the variability
of cardiac frequency study, the alternance of T-
wave study, the transesophageal electrophysiology
study at rest and under stress, and the endocavitary
electrophysiology study.
16.3 Indications for
Electrophysiological Studies
in Athletes
An electrophysiology study is part of the third
level of the evaluation of an athlete. It may be in-
dicated based on the symptoms reported by the
subject and the arrhythmias found during the sec-
ond-level tests, in particular surface ECG, Holter
ECG and the maximum stress test. The symp-
toms most often reported by athletes include pal-
pitation at rest and under stress, and occasionally
pre-syncopal and/or syncopal episodes. All symp-
toms, however, need a high degree of attention and
diagnostic accuracy.
As for the selection criteria for an electrophysi-
ological endocavitary study, the usual indications for
this exam must be valid both for athletes and seden-
tary subjects. However, in athletes, other indica-
tions for an electrophysiological endocavitary study
are more closely related to arrhythmic risk tests in
connection with sport, e.g. with Wolff-Parkinson-
White (WPW) syndrome. Furthermore, it includes
not only the diagnostic results but also the possible
therapeutic results. In other words, invasive electro-
physiological studies are certainly indicated in ath-
letes when there is also an indication for ablative
treatment of a certain arrhythmia (see Chapter 17).
Based on a subject’s symptoms it is possible to
propose an invasive electrophysiological evalua-
tion in the presence of: recurrent syncopal episodes
associated with palpitations [3] (suspected pres-
ence of tachyarrhythmias); syncopal episodes in
presence of heart disease that is not the cause of
non-suitability or familiarity with sudden death,
following second-level assessments; paroxysmal
palpitations and/or hemodynamic compromise; pal-
pitations with a strong suspicion of supraventricu-
lar tachycardia; palpitation in subjects with heart
disease or suspected ventricular tachycardia.
On the other hand, an electrophysiological study
can be indicated even if specific arrhythmias or ar-
rhythmogenic conditions are found during the first-
and/or second-level assessments. Obviously, even
in this situation, a possible indication for a more in-
depth invasive electrophysiological study cannot
involve clinical elements and the patient’s medical
history, which provide a clinical classification of
the arrhythmic problem in the subject, ruling out or
confirming, for example, the presence of a poten-
tial underlying structural cardiopathy.
As for bradyarrhythmias, an electrophysiolog-
ical study can be taken into consideration with the
objective of studying supra-Hisian, infra-Hisian
and sub-Hisian atrioventricular conduction, only
in the presence of any type of atrioventricular
block, only if these are associated with delays in
intra-ventricular conduction, and in the rare cases
in which second-degree atrioventricular block
with narrow QRS is found during physical exer-
tion [4,5].
In patients with supraventricular tachycardia,
electrophysiological studies can be indicated in the
case of: paroxysmal forms in which re-entrant
tachycardia is suspected (nodal tachycardia, atri-
oventricular re-entrant tachycardia); paroxystic
supraventricular tachycardia in the absence of
WPW syndrome during surface ECG to investi-
gate whether arrhythmias induced during the elec-
trophysiological study do not have a high fre-
quency; iterative and persistent supraventricular
tachycardia (for example inappropriate sinusal
tachycardia, re-entrant tachycardia through a slow
decremental accessory pathway, Coumel tachy-
cardia and focal atrial tachycardia resulting from
increased automaticity); identification of possi-
ble triggers the paroxystic atrial fibrillation, such
as nodal re-entrant tachycardia or an accessory
16 Electrophysiological Studies in Athletes 187

4. pathway, pulmonary venous foci with the related
possibility of ablation; asymptomatic subjects af-
fected by WPW syndrome and in absence of un-
derlying heart disease (with the exception of chil-
dren under 12 years of age since, according to the
COCIS, the stratification of risk can be envisaged
beyond this age).
A separate and in-depth consideration needs be
reserved for the value of the electrophysiological
study in ventricular pre-excitation syndrome, and
more precisely in WPW syndrome. Physical activ-
ity, as is known, promotes the trigger of certain
cardiac arrhythmias, and this is true even in ven-
tricular preexcitation. In WPW syndrome a theo-
retical risk of sudden death exists, albeit very low.
This risk is directly connected to the presence of
atrial fibrillation (generally, even if not exclu-
sively, triggered by atrioventricular re-entrant
tachycardia) and by an accessory pathway with an
elevated anterograde conductive capacity from the
atria to the ventricles. The arrhythmic risk is not
deducible by non-invasive clinical and structural
parameters and can occur even in a completely
asymptomatic subject. All risk parameters con-
nected to the syndrome are, however, easily iden-
tifiable in the course of the electrophysiological
study. Therefore, this study is generally indicated
in competitive subjects with ventricular preexcita-
tion and can be carried out via both the trans-
esophageal and endocavitary pathways (see
above). According to the judgment of experts at
the COCIS, the invasive electrophysiological eval-
uation can be delayed in asymptomatic subjects
below 12 years of age, due to the almost virtual
risk of atrial fibrillation and sudden death. On the
basis of the parameters of the electrophysiological
study, suitability to perform competitive activi-
ties can be conceded in asymptomatic subjects
and those without heart disease: atrial preexcita-
tion fibrillation inducibility with a minimum R-R
interval > 240 ms (baseline conditions) and > 200
ms (under stress); non inducibility of atrial fibril-
lation and/or atrioventricular re-entrant tachycar-
dia at rest and under stress, and an anterograde ef-
fective refractory period of the accessory pathway
> 240 ms at rest and > 200 ms under stress [6,7].
Ventricular tachycardias in the presence of as-
serted organic heart disease are not covered by the
present study, as they occur in subjects for whom the
problem of competitive suitability cannot be taken
into consideration. Nonetheless, electrophysiologi-
cal endocavitary studies can be useful in certain
forms of ventricular tachycardia which are suppos-
edly benign, namely in subjects without significant
structural heart disease. These arrhythmic forms
mainly include: fascicular ventricular tachycardia,
ectopic idiopathic ventricular tachycardia originat-
ing from the right and, more rarely, left ventricular
outflow tract. Even for these arrhythmias the idea
that an electrophysiological study is still indicated
when an ablative indication also subsists is valid.
Furthermore, in certain cases, it may be difficult to
conduct a differential diagnosis based on first- and
second-level studies, between ventricular tachycar-
dia of the right ventricular outflow tract and ventric-
ular tachycardia of the right ventricular outflow tract
in the context of arrhythmogenic myocardiopathy of
the right ventricle. Electrophysiological endocavi-
tary studies can provide useful data for the differen-
tial diagnosis. In fact, in arrhythmic cardiopathy,
ventricular stimulation easily tends to induce sus-
tained ventricular tachycardia based on the re-entry
mechanism (presence of the phenomenon of con-
cealed entrainment). Instead, in idiopathic ventric-
ular tachycardias, often only the stimulation after in-
fusion of isoproterenol is capable of reproducing
such arrhythmias (catecholamine-mediated tachy-
cardia resulting from an intensified automatism).
Ventricular fascicular tachycardia, in some cases,
can be confused with paroxystic supraventricular
tachycardias conducted with aberration. In these
cases, electrophysiological study results are ex-
tremely useful for clear differential diagnosis [8-10].
16.4 Possible New Areas
of Application
Electrophysiological endocavitary studies can be
carried out with specific catheters that allow three-
dimensional mapping of the cardiac chambers,
providing both electric and anatomic (elec-
troanatomic maps) information. This is made pos-
sible by increasingly accurate mapping systems
and three-dimensional non-fluoroscopic naviga-
tion. These systems enable the localization of the
L. Sciarra et al.188

5. letes with malignant ventricular arrhythmias, help-
ing to identify or rule out the presence of potential
underlying structural heart disease.
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Parkinson-White: what to do. Extensive ablation or
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7. Brembilla-Perrot B, Ghawi R et al (1993) Electrophy-
siological characteristics of asymptomatic Wolff-Par-
kinson-White syndrome. Eur Heart J 14:511-515
8. Heidbüchel H, Hoogsteen J, Fagard R et al (2003)
High prevalence of right ventricular involvement in en-
durance athletes with ventricular arrhythmias. Role of
an electrophysiologic study in risk stratification. Eur
Heart J 24:1473-1480
9. Biffi A, Ansalone G, Verdile L et al (1996) Ventricular
arrhythmias and athletes heart Role of signal-averaged
electrocardiography. Eur Heart J 17:557-563
10. Furlanello F, Bettini R, BertoldiA et al (1989)Arrhyth-
mia patterns in athletes with arrhythmogenic right ven-
tricular dysplasia. Eur Heart J 10 Suppl D:16-19
11. L. Sciarra, E. Marras, E. De Ruvo et al (2008) Right
ventricular voltage mapping. In Brugada Syndrome: al-
ways an electrical disease in structurally normal hearts?
Heart Rhythm:S74
12. Corrado D, Basso C, Leoni L et al (2005) Three-di-
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13. Corrado D, Basso C, Leoni L et al (2008) Three-di-
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16 Electrophysiological Studies in Athletes 189
Fig. 16.3 Example of the bipolar voltage map of the right
ventricle reconstructed by the three-dimensional elec-
troanatomical mapping system (CARTO®, Biosense
Webster). The anteroposterior view shows a wide low-
voltage area (red regions) in the right ventricular free wall,
a peritricuspid area and basal region of the right ventricu-
lar outflow tract. Scar areas (red) are surrounded by low-
voltage areas (yellow-blue). Purple areas identify normal
myocardial tissue. The patient is an athlete with a Brugada
type ECG pattern. As is well known, Brugada is a syn-
drome that affects patients with a structurally normal heart.
The electroanatomical mapping has shown structural ab-
normalities of the right ventricle. The subject is obviously
not suitable for practicing sport
electrocatheters through the emission of mag-
netic fields and/or the use of electric impedance.
Maps of this kind are certainly more useful for
supporting ablative interventions of complex ar-
rhythmias. Furthermore, some of these three-di-
mensional maps can also enable adequate meas-
urement of the voltage of endocavitary signals
registered by the electrocatheter [11,12]. It is in-
tuitive to see how, in case of an eventual scar
area on the ventricular muscle, or an area substi-
tuted by fibrous or fibroadipose tissue, the catheter
positioned in these regions can register very low
signals or signals that are completely absent (Fig.
16.3). This type of reconstruction has proven to be
very useful, for example, as published by the Ital-
ian group of Corrado, in the diagnosis of the ar-
rrhythmogenic cardiopathy of the right ventricle
[13]. It is also possible to predict that this method
could be used even in the diagnostic course of ath-