p.38 抽出テキスト

.......................................................................................... over the AP, may also be used, even if they may not restore sinus rhythm.429431 However, class Ic drugs should be used with caution as they do exert an effect on the AVN. In pre-excited AF, i.v. amiodarone may not be as safe as previously thought, because enhanced pathway conduction and ventricular fibrillation have been reported, and should not be considered.432435 Procainamide appears to be safer in this setting.436

11.3.10.2 Catheter ablation The treatment of choice for patients with symptomatic and recurrent AVRT, or pre-excited AF, is catheter ablation (Figure 21). For other patients with asymptomatic and infrequent episodes, therapeutic decisions should be balanced between the overall risks and benefits of the invasive nature of ablation vs. long-term commitment to pharmacological therapy. Ablation of the AP has a high acute success rate and is associated with a low complication rate depending on the pathway location (Table 9).391393,438440 Major complications include cardiac tamponade (0.131.1%) and complete AV block (0.172.7%) in patients in whom ablation of septal APs is attempted. With septal APs close to the AVN, the ECG typically displays a positive delta wave in leads avF and avL, and a narrow positive delta wave in lead V1 that has a prominently negative QRS complex.394 When targeting septal pathways and applying cryoenergy, the incidence of AV block is lower compared with radiofrequency energy.447 However, recurrence of previously blocked pathways has been reported to be significantly higher when cryoenergy is applied.438 Two approaches are available for left-sided pathways: an antegrade transseptal and a retrograde aortic approach. There is evidence that the transseptal approach, in experienced hands, results in reduced radiation and procedure times.441,448 The 2015 American College of Cardiology/American Heart Association/Heart Rhythm Society Guideline for the Management of Adult Patients With Supraventricular Tachycardia reported major complication rates after radiofrequency catheter ablation of 3.0 and 2.8% for AVNRT and AVRT, respectively.2 These rates are much higher than those reported by experienced electrophysiologists in the current era, as summarized in Table 9, but the procedure still carries a very small, non-negligible, mortality risk.203,205

11.3.10.3 Chronic therapy If ablation is not desirable or feasible in patients with preexcitation and symptomatic antidromic AVRT, and in whom structural or ischaemic heart disease has been excluded, class IC antiarrhythmic drugs act mainly on the AP and can be used in antidromic tachycardia (Figure 21).429,437,444,445 In cases of preexcited AF, caution should be taken not to transform it into atrial flutter and induce 1:1 conduction. Apart from class IC drugs, betablockers, diltiazem, or verapamil may also be considered in case of orthodromic tachycardias if no signs of pre-excitation are observed on the resting ECG.340,341,442,443

11.3.11 The asymptomatic patient with pre-excitation Most patients with an asymptomatic WPW pattern will go through life without any clinical events related to their ventricular pre-excitation. Approximately one in five patients will develop an arrhythmia related to their AP during follow-up. The most common arrhythmia in patients with WPW syndrome is AVRT (80%), followed by a 2030% incidence of AF. Sudden cardiac death

©ESC 2019

Catheter ablation

(I B)

Propafenone or flecainide

(IIb B) Diltiazem or verapamil or beta-blocker

(IIa B)

No

No

No

Yes

Yes

Yes

If ineffective If ineffective

Symptomatic and

recurrent

Drug therapy

desirable

Orthodromic

AVRT

AVRT

Figure 21 Chronic therapy of atrioventricular re-entrant tachycardia. AVRT = atrioventricular re-entrant tachycardia.

©ESC 2019

Pre-excited AF

Synchronized cardioversion

(I B)

Yes No

If ineffective Haemodynamic

instability

i.v. ibutilide or procainamide

(IIa B) i.v. flecainide or

propafenone

(IIb B)

Figure 20 Acute therapy of pre-excited atrial fibrillation. AF = atrial fibrillation; i.v. = intravenous. Downloaded from academic.oup.com/eurheartj/article/41/5/655/5556821 by guest on 07 October 2026