Paroxysmal ventricular tachycardia in Wolff-Parkinson-White syndrome: case report and review of the literature

One symptom, two arrhythmias: the rare and the even rarer

Background

Wolff-Parkinson-White (WPW) syndrome and idiopathic left ventricular tachycardia (ILVT) are rare and up to now the coexistence of both entities has rarely been reported.

In patients with ventricular preexcitation the underlying mechanism of paroxysmal tachycardia most likely is atrioventricular reentrant tachycardia (AVRT). However, without ECG documentation of the tachycardia diagnosis of the underlying mechanism cannot be made due to similar clinical presentation of AVRT and ILVT.

Case presentation

We report a case of a two-staged occurrence of two rare arrhythmias in a young adult, who was admitted to our hospital twice within 6 months because of paroxysmal tachycardia. WPW syndrome and ILVT as underlying arrhythmias have been diagnosed and were ablated successfully.

Conclusions

This case highlights the diagnostic defiance of rare tachycardia entities and the paramount importance of ECG documentation and analysis of all available tachycardia ECGs.

Myocardial Bundles with Slow Conduction Properties are Present on the Left Interventricular Septal Surface of Normal Human Hearts

INTRODUCTION

The aim of this study was to examine the electrophysiologic characteristics of the normal left interventricular septum (LIVS).

METHODS AND RESULTS

We explored the LIVS in search of endocardial potentials following ventricular electrograms during sinus rhythm in 28 patients without structural heart disease. In all patients, low-frequency (mean amplitude: 0.81 +/- 0.33 mV) systolic potentials (LA1) were detected in a basal-to-apical activation sequence (earliest to latest QRS-LA1 interval: 93.3 +/- 10.8 ms to 127.1 +/- 16.6 ms). Programmed stimulation demonstrated decremental conduction properties, and the effective refractory period of the tissue between the ventricular electrogram and LA1 at baseline (376.7 +/- 48.8 ms) was significantly prolonged by disopyramide (421.3 +/- 54.1 ms, P < 0.05 vs baseline). In 21 patients (75%), diastolic potentials (LA2) morphologically similar to LA1 (mean amplitude: 0.52 +/- 0.17 mV) were detected in an apical-to-basal activation sequence (earliest to latest QRS-LA2 interval: 368.9 +/- 32.4 ms to 440.7 +/- 45.8 ms). Para-Hisian pacing with capture of the His bundle showed shorter S-LA1 and S-LA2 intervals compared to the beats without His-bundle capture but with ventricular capture (156.3 +/- 11.2 ms vs 183.2 +/- 12.3 ms, and 385.7 +/- 21.6 ms vs 397.4 +/- 23.4 ms, respectively, P < 0.0001). At the same rate, the LA1-LA2 interval was significantly shorter during right ventricular apical than atrial overdrive pacing (220.4 +/- 23.1 ms vs 261.4 +/- 30.7 ms, P < 0.0001).

CONCLUSION

Unique myocardial bundles with slow conduction properties and various electrical connections with the specialized conduction system may exist in the LIVS of normal human hearts.

Inducible multiform ventricular tachycardia in Wolff-Parkinson-White syndrome

The induction of ventricular tachycardia by ventricular stimulation was investigated in 46 patients with isolated Wolff-Parkinson-White syndrome (10 concealed) and 36 control patients with normal electrocardiograms and conduction systems. None of those studied had spontaneous ventricular arrhythmias or myocardial or valve disease. Single and double ventricular extrastimuli were delivered at 3 cycle lengths (sinus, 600 ms, 400 ms). In the controls ventricular simulation induced one episode (3%) of non-sustained ventricular tachycardia. Ventricular stimulation in patients with Wolff-Parkinson-White syndrome induced two episodes of ventricular fibrillation and 15 episodes of non-sustained multiform ventricular tachycardia (37%). Ventricular arrhythmias were induced only in patients with overt Wolff-Parkinson-White syndrome. In 14 patients the conformation of the electrocardiogram at the start of ventricular tachycardia resembled that of major pre-excitation. The absence of inducible ventricular tachycardia in patients with concealed Wolff-Parkinson-White syndrome suggests that anterograde conduction via an atrioventricular accessory pathway is required to initiate the ventricular arrhythmias: the ventricular tachycardia may be associated with reentry of impulses via atrioventricular connection during the phase of ventricular vulnerability. The similarity between the start of ventricular tachycardia and pre-excitatory complexes may also indicate local reentry into the ventricular area occupied by the bypass tracts. Patients with Wolff-Parkinson-White syndrome and anterograde pre-excitation are more likely to have inducible multiform ventricular tachycardia than individuals without Wolff-Parkinson-White syndrome.