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................................................................................................................... 5.6.3 Supraventricular tachycardia and Wolff-Parkinson- White syndrome The term paroxysmal supraventricular tachycardia (PSVT) includes (i) atrioventricular nodal re-entrant tachycardia (AVNRT; most common); (ii) atrioventricular re-entrant tachycardia (AVRT) involving an accessory pathway; or (iii) atrial tachycardia.

Ventricular pre-excitation on the resting ECG is due to an accessory pathway (AP) with antegrade conduction. The prevalence of pre-excitation in the general population varies from 0.10.3%.491,492 Wolff-Parkinson-White (WPW) syndrome is defined as the presence of paroxysmal arrhythmias in a patient with pre-excitation.

5.6.3.1 Prognostic and symptomatic relevance of paroxysmal supraventricular tachycardia without pre-excitation PSVT without pre-excitation and without associated structural heart disease is not life-threatening, although the arrhythmia may result in dizziness and exhaustion that requires cessation of exercise. Syncope is uncommon. Pre-excitation, however, may be associated with sudden death (see later); therefore, it is important to exclude the presence of latent pre-excitation, by performing carotid sinus massage or an adenosine-test in sinus rhythm.493 Athletes with PSVT should stop exercise in the event of palpitations since rapid heart rates may cause (pre)syncope. Individuals with proven PSVT without pre-excitation should be educated on how to safely perform vagal manoeuvres (such as carotid sinus massage or, preferably, Valsalva manoeuvre) to facilitate termination of the arrhythmia.494 Exercise may be resumed after termination of the arrhythmia. Prophylactic drug treatment with beta-blockers or calcium antagonists with atrioventricular nodal blocking properties can be considered, although it has limited efficacy. Class I drugs have no role in the management of PSVT, since they can cause lifethreatening arrhythmias (see earlier). If competitive athletic activity is desired, curative treatment by ablation should be considered. Ablation outcome is equally safe and has similar acute success rates in athletes and non-athletes.495 If the PSVT is only sporadic and transient and not associated with haemodynamic consequences, even when it develops during exercise, or in cases where ablation is not desired or unsuccessful, sports activity is permissible when there is no increased risk of a fatality from a potential loss of consciousness (such as motorsports drivers, parachute jumpers, divers, and so on).

5.6.3.2 Prognostic and symptomatic relevance of pre-excitation It has been estimated that one third of patients with WPW syndrome may develop AF and, in such cases, rapid conduction over the AP can lead to ventricular fibrillation (VF) and sudden death. Given the fact that AF is more common in athletes, pre-excitation constitutes a prognostic concern in athletes. The risk for sudden death in patients with pre-excitation varies in population-based studies from 0.150.20%, and usually presents during exercise or emotional stress.496 Evaluation of the athlete with ventricular pre-excitation should exclude associated structural cardiac disease, such as HCM or Ebstein anomaly. Minimal or ‘latent’ pre-excitation can be unmasked on a 12lead ECG during sinus rhythm by vagal manoeuvres or intravenous administration of adenosine. Prolongation of the PR interval without a change in the QRS morphology, or transient atrioventricular block, excludes non-intermittent latent pre-excitation. Pre-excitation may be intermittent, which usually indicates low risk properties of the pathway. However, some accessory pathways may be potentiated by adrenergic stimuli. Therefore, exercise testing excluding pre-excitation at peak exercise is recommended before clearance for sports.

Ablation of the AP is recommended in competitive and recreational athletes with pre-excitation and documented arrhythmias. In the event of transient, infrequent well-tolerated arrhythmia (even during exercise), good anticipation of an ablation procedure with increased risk (e.g. anteroseptal AP), or reluctance of the athlete to undergo ablation, management should be guided by assessment of the antegrade conduction characteristics of the AP using either noninvasive tests or an invasive electrophysiological (EP) study. Non-invasive investigation examines for intermittent preexcitation on ECG or Holter, for abrupt disappearance of preexcitation after administration of a low dose of class I drugs, or for its abrupt disappearance during an exercise test.497 In cases of a long refractory period and hence low risk for sudden death, continuation of sports activity is permitted without ablation on the understanding that sporting activity should be stopped in the event of recurrence of palpitations. In competitive athletes with asymptomatic pre-excitation an EP study is warranted to evaluate the risk for sudden death. In the event of a high-risk finding (Table 15), ablation of the AP is recommended. For athletes who refuse ablation, or if the procedure is associated with high risk, such as an anteroseptal accessory pathway, participation in competitive sports activities can be discussed on an individual case by case basis including the use of pharmacological therapy, although there are currently no data about its efficacy. Sports in which the potential loss of consciousness could be fatal should be discouraged. In recreational athletes with asymptomatic pre-excitation, risk assessment may first be pursued via non-invasive testing.497 The sensitivity of non-invasive screening for AP properties that facilitate a fast ventricular response to AF/AFL is good, but its specificity is low.498 Of note, in children younger than 12 years, the risk of AF-induced VF and sudden death is very low. Generally, a conservative approach

Table 15 Findings during an invasive electrophysiological study (with the use of isoprenaline) indicating an accessory pathway with increased risk of sudden death

©ESC 2020

AF = atrial fibrillation; AVRT = atrioventricular re-entrant tachycardia. Downloaded from academic.oup.com/eurheartj/article/42/1/17/5898937 by guest on 07 October 2026