Disopyramide stress test: A sensitive and specific tool for predicting impending high degree atrioventricular block in patients with bifascicular block

Author(s): Bergfeldt, L., Rosenqvist, M.

Journal/Book: Br Heart J. 1995; 74: British Med Assoc House, Tavistock Square, London, England WC1H 9JR. British Medical Assoc. 650-655.

Abstract: Objective-To study the value of intravenous disopyramide as part of an invasive electrophysiological study in predicting impending high degree atrioventricular block in patients with bifascicular block. Design-An invasive electrophysiological study was performed in the basal state and after the infusion of disopyramide (2 mg/kg body weight). The progression to high degree atrioventricular block was assessed by bradycardia-detecting pacemakers or repeated 12-lead electrocardiogram recordings, or both. Patients-73 patients with bifascicular block were included, of whom 25 had a history of unexplained syncope. The remaining 48 patients had no arrhythmia related symptoms and were included as controls. All patients had an ejection fraction of > 35%. Results-After a mean follow up of 23 months, seven patients in the syncope group and three in the non-syncope group had a documented high degree atrioventricular block or pacemaker-detected bradycardia of less than or equal to 30 beats/min for greater than or equal to 6 s. The sensitivity of the disopyramide test was 71% and the specificity 98%. The corresponding figures for an abnormal electrophysiological study in the basal state were 14% and 91%, respectively. Conclusions-The sensitivity of an invasive electrophysiological study in patients with bifascicular block and syncope can be markedly increased by the use of intravenous disopyramide. A positive test is a highly specific finding and warrants pacemaker implantation.

Note: Article A Englund, Karolinska Hosp, Dept Cardiol, Thorac Clin, S-17176 Stockholm, Sweden

Keyword(s): disopyramide stress test; atrioventricular block; bifascicular block; electrophysiological study; BUNDLE-BRANCH BLOCK; UNEXPLAINED SYNCOPE; PACEMAKER; INTERVAL

Zurück | Weiter