Clinical Research
Heart Rhythm Disorder
Malignant Entity of Idiopathic Ventricular Fibrillation and Polymorphic Ventricular Tachycardia Initiated by Premature Extrasystoles Originating From the Right Ventricular Outflow Tract

Presented in part at Heart Rhythm 2004, San Francisco, California, May 19–22, 2004, and published in abstract form (Heart Rhythm 2004;1[IS]:S269).
https://doi.org/10.1016/j.jacc.2005.05.077Get rights and content
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Objectives

The aim of this study was to assess the clinical characteristics and the efficacy of radiofrequency catheter ablation (RFCA) for idiopathic ventricular fibrillation (VF) and/or polymorphic ventricular tachycardia initiated by ventricular extrasystoles originating from the right ventricular outflow tract (RVOT).

Background

Ventricular fibrillation and/or polymorphic ventricular tachycardia are occasionally initiated by ventricular extrasystoles originating from the RVOT in patients without structural heart disease.

Methods

Among 101 patients without structural heart disease in whom RFCA was conducted for idiopathic ventricular tachyarrhythmias arising from the RVOT, we examined the clinical characteristics and the efficacy of RFCA in 16 patients with spontaneous VF and/or polymorphic ventricular tachycardia initiated by the ventricular extrasystoles originating from the RVOT.

Results

Among 16 patients, spontaneous episodes of VF were documented in 5 patients, and 11 patients had prior episodes of syncope. Holter recordings showed frequent isolated ventricular extrasystoles with the same morphology as that of initiating ventricular extrasystoles, and non-sustained polymorphic ventricular tachycardia with short cycle length (mean of 245 ± 28 ms) in all 16 patients. Radiofrequency catheter ablation by targeting the initiating ventricular extrasystoles eliminated episodes of syncope, VF, and cardiac arrest in all patients during follow-up periods of 54 ± 39 months.

Conclusions

Our data suggest that the malignant entity of idiopathic VF and/or polymorphic ventricular tachycardia was occasionally present in patients with idiopathic ventricular arrhythmias arising from the RVOT. Radiofrequency catheter ablation was effective as a treatment option for this entity.

Abbreviations and Acronyms

ECG
electrocardiogram
EPS
electrophysiologic study
ICD
implantable cardioverter-defibrillator
PVC
premature ventricular contraction
PVT
polymorphic ventricular tachycardia
RFCA
radiofrequency catheter ablation
RVOT
right ventricular outflow tract
SAECG
signal-averaged electrocardiogram
VE
ventricular extrasystoles
VF
ventricular fibrillation

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Dr. Shimizu was supported in part by the Mitsubishi Pharma Research Foundation, Health Sciences Research Grants from the Ministry of Health, Labor, and Welfare, and Research Grants for Cardiovascular Diseases (15C-6) from the Ministry of Health, Labor and Welfare, Japan.