Evidence that nonsustained polymorphic ventricular tachycardia causes syncope (data from implantable cardioverter defibrillators)

Abstract

Patients with syncope account for ≅6% of hospital admissions and 3% of emergency room visits. 1 Kapoor W.N. Evaluation and management of syncope. JAMA. 1992; 268: 2553-2560 Crossref PubMed Scopus (245) Google Scholar Whether and how often nonsustained ventricular fibrillation (VF) or nonsustained polymorphic ventricular tachycardia (NSPMVT) can cause syncope is not entirely clear. In patients with the long QT syndrome, nonsustained Torsades de Pointes causing syncope is well described. Other reports, generally in patients with normal hearts, have occasionally described the association of NSPMVT and syncope. 2 Viskin S. Belhassen B. Idiopathic ventricular fibrillation. Am Heart J. 1990; 120: 661-671 Abstract Full Text PDF PubMed Scopus (188) Google Scholar , 3 Schwartz S.P. Studies on transient ventricular fibrillation. IV. Observations on clinical and graphic manifestations following revival of the heart from transient ventricular fibrillation. Am J Med Sci. 1936; 192: 808-815 Crossref Google Scholar , 4 Dubner S.J. Gimeno G.M. Elencwajg B. Leguizamon J. Tronge J.E. Quintero R. Ventricular fibrillation with spontaneous reversion on ambulatory electrocardiogram in the absence of heart disease. Am Heart J. 1983; 105: 691-693 Abstract Full Text PDF PubMed Scopus (33) Google Scholar , 5 Patt M.V. Podrid P.J. Friedman P.L. Lown B. Spontaneous reversion of ventricular fibrillation. Am Heart J. 1988; 115: 919-921 Abstract Full Text PDF PubMed Scopus (23) Google Scholar , 6 Masrani K. Cowley C. Bekheit S. El-Sherif N. Recurrent syncope for over a decade due to idiopathic ventricular fibrillation. Chest. 1994; 106: 1601-1603 Crossref PubMed Scopus (15) Google Scholar However, it is generally believed that VF is a sustained tachyarrhythmia that results in death 7 Olshansky B. Syncope overview and approach to management. in: Olshansky B. Syncope Mechanisms and Management. Futura Publishing Co, Inc, Armonk, NY1998: 15-71 Google Scholar and that NSPMVT is unusual as a cause of syncope. The current generation of implantable cardioverter defibrillators (ICDs) with intracardiac electrogram storage offer an opportunity to evaluate the incidence of NSPMVT relative to sustained VF and to document the association of syncope and presyncopal symptoms with these arrhythmias.