Elsevier

Journal of Electrocardiology

Volume 51, Issue 5, September–October 2018, Pages 874-878
Journal of Electrocardiology

Review
New Insights on Verapamil-Sensitive Idiopathic Left Fascicular Tachycardia

https://doi.org/10.1016/j.jelectrocard.2018.06.007Get rights and content

Abstract

Verapamil-sensitive left fascicular monomorphic ventricular tachycardia (LF-VT) was first described ~4 decades ago. Our knowledge regarding this arrhythmia is evolving continuously. The current review aims to highlight up to date aspects of this arrhythmia focusing on its ECG recognition, new considerations of the reentrant circuit, ablation targets in inducible and non-inducible patients and the approach to LF-VT with multiform morphology.

Introduction

Verapamil-sensitive left fascicular monomorphic ventricular tachycardia (LF-VT) is a Purkinje-related arrhythmia mainly occurring in patients with structurally normal heart [1,2]. Underlying mechanism is assumed to be reentry in most cases [1,3] while non-reentrant mechanism is rarely involved [4]. Although the first case was reported in a young white man by Belhassen et al. [5], the arrhythmia largely prevails in South East Asia [2,6]. The most common type called “Belhassen VT” [5,7] exits near the left posterior fascicle (LPF) and exhibits a morphology of right bundle branch block (RBBB) and left axis deviation. Less often LF-VT may exit near the left anterior fascicle [8] or involve the septal fascicle. LF-VT is frequently induced by atrial as well as right ventricular (RV) or left ventricular (LV) stimulation [9]. When indicated, ablation is usually a highly effective treatment [10,11]. In the current mini review our aim is to highlight new aspects of this arrhythmia including its ECG recognition, new understandings about the reentrant circuit, ablation targets in inducible and non-inducible patients and the approach to LF-VT with multiform morphology.

Section snippets

ECG recognition of LPF VT

LPF-VT, the most common type of LF-VT is frequently misdiagnosed as supraventricular tachycardia with RBBB and left anterior hemiblock aberrancy especially when capture, fusion beats or atrioventricular (AV) dissociation are not seen [12,13]. Recently, our group described 4 variables that may help distinguishing the QRS morphology of LPF-VT from aberrancy (Fig. 1). Atypical V1 morphology (no rsR', or R larger than R'), QRS width ≤ 140 ms, R/S ratio ≤ 1 and positive aVR were associated with the

The reentrant circuit

In their seminal work [16], Nogami and colleges showed that in 75% of patients with LPF-VT a diastolic potential “P1”, involving abnormal Purkinje tissue showing decremental properties and Verapamil sensitivity, can be recorded. A second presystolic potential (P2 or LPF potential) with a distal to proximal activation may also be recorded during VT. Thus, initially it was proposed that the abnormal Purkinje tissue (P1) serves as an antegrade limp and the LPF serves as the retrograde limb of the

EP study and ablation (Table 1)

As already mentioned LF-VT can be induced by atrial as well as RV or LV extra-stimulus pacing [9]. The usual targets for ablation include either the diastolic potential (P1) or the earliest presystolic P2 potential [1,16]. Since it is a macro reentrant circuit there is usually >1 target that may lead to successful ablation [1,16]. However, ablation is usually performed at the mid to distal two thirds of the septum to avoid the risk of damaging the left bundle branch system or the AV node when

Multiform morphology

LF-VT usually presents with a single ECG morphology, however 5–30% of cases may manifest changing QRS morphology [[38], [39], [40], [41]]. This change in morphology may occur spontaneously or be related to ablation or catheter induced mechanical injury to one of the fascicles. Mechanisms of multiform morphology include a completely new reentrant circuit [39], ablation of a proximal connection between P1 and P2 with continued reentrant circuit using a more distal connection between P1 and P2

In conclusion

Since the initial description of LPF-VT [5,43] our understanding of this fascinating arrhythmia continues to evolve in terms of its ECG recognition, its mechanism and in treating the common as well as the uncommon and multiform fascicular arrhythmia.

8 major references dealing with the present review

  • Belhassen B, Shapira I, Pelleg A, Copperman I, Kauli N, Laniado S. Idiopathic recurrent sustained ventricular tachycardia responsive to verapamil: an ECG-electrophysiologic entity. Am Heart J. 1984;108:1034–7.

  • Ohe T, Shimomura K, Aihara N, Kamakura S, Matsuhisa M, Sato I, et al. Idiopathic sustained left ventricular tachycardia: clinical and electrophysiologic characteristics. Circulation. 1988;77:560–8. Erratum in: Circulation 1988;78:A5

  • Nakagawa H, Beckman KJ, McClelland JH, Wang X, Arruda M,

Disclosure

None.

References (43)

  • R. Sung et al.

    Spectrum of fascicular arrhythmias

    Card Electrophysiol Clin

    (2016)
  • D.P. Zipes et al.

    Atrial induction of ventricular tachycardia: reentry versus triggered automaticity

    Am J Cardiol

    (1979)
  • A. Nogami

    Purkinje-related arrhythmias part I: monomorphic ventricular tachycardias

    Pacing Clin Electrophysiol

    (2011)
  • B. Belhassen et al.

    Idiopathic ventricular tachycardia and fibrillation

    J Cardiovasc Electrophysiol

    (1993)
  • F. Ouyang et al.

    Electroanatomic substrate of idiopathic left ventricular tachycardia: unidirectional block and macroreentry within the Purkinje network

    Circulation

    (2002)
  • A.K. Talib et al.

    Non-reentrant fascicular tachycardia: clinical and electrophysiological characteristics of a distinct type of idiopathic ventricular tachycardia

    Circ Arrhythm Electrophysiol

    (2016)
  • B. Belhassen et al.

    Response of recurrent sustained ventricular tachycardia to verapamil

    Br Heart J

    (1981)
  • T. Ohe et al.

    Idiopathic sustained left ventricular tachycardia: clinical and electrophysiologic characteristics

    Circulation

    (1988)
  • A. Nogami et al.

    Verapamil-sensitive left anterior fascicular ventricular tachycardia: results of radiofrequency ablation in six patients

    J Cardiovasc Electrophysiol

    (1998)
  • A. Gopi et al.

    A stepwise approach to the induction of idiopathic fascicular ventricular tachycardia

    J Interv Card Electrophysiol

    (2015)
  • Y. Liu et al.

    Catheter ablation of fascicular ventricular tachycardia: long-term clinical outcomes and mechanisms of recurrence

    Circ Arrhythm Electrophysiol

    (2015)
  • Cited by (7)

    • Arrhythmias

      2022, Comprehensive Pharmacology
    • Tachyarrhythmias arising from the conduction system in pediatric patients with complete heart block

      2022, HeartRhythm Case Reports
      Citation Excerpt :

      Idiopathic fascicular VT represents 10%–15% of VT related to the LV in structurally normal hearts and was first described by Cohen and colleagues2 and Zipes and colleagues.3 While fascicular VT may arise from the anterior or posterior fascicle, the most common type (90%) arises from the posterior fascicle4 and is characterized by a relatively narrow ventricular rhythm with a right bundle branch block morphology with a superior/leftward axis, thought due to reentry with exit near the left posterior fascicle.5 Although there are reports of fascicular VT in patients with minor CHD (atrial and ventricular septal defects, mitral valve prolapse),4,6 to the best of our knowledge this represents the first report of fascicular VT in a patient with CHB.

    • Anti-arrhythmic therapy in athletes

      2019, Pharmacological Research
      Citation Excerpt :

      Verapamil-sensitivity is a distinctive feature of this arrhythmia but some individuals may experience recurrences despite calcium-channel-blockers. For these patients, or in case the drug is not tolerated, catheter ablation represents an alternative treatment that is effective in the majority of cases [68]. Recommendations for treatment and eligibility to competitive sports activity in athletes with arrhythmias and structurally normal heart according to the 2015 American Heart Association/American College of Cardiology [2], the 2005 European Society of Cardiology [9] and the 2017 Italian Society of Sports Cardiology (COCIS) [69] guidelines for sports eligibility are summarized on Table 3

    • Broad-complex tachycardia in a young athlete

      2020, Cardiac Electrophysiology: Clinical Case Review
    View all citing articles on Scopus
    View full text