title: Initiation of ventricular tachycardia by supraventricular beats.
abstract: 9 patients (6 males and 3 females, age 5-69 years) with ventricular tachycardia induced by supraventricular beats are reported. 3 patients had had previous myocardial infarction, 1 patient had mitral valve prolapse and in 5 patients no organic heart disease could be demonstrated. Ventricular tachycardia was initiated by a single atrial premature beat in 4 patients, double atrial premature beats in 3 patients (in 1 of them following exercise), by nonsustained AV nodal tachycardia in 1 patient, by rapid atrial pacing in 3 patients and exercise-related ectopic atrial tachycardia in 1 patient. Programmed ventricular stimulation induced ventricular tachycardia in all patients in whom the tachycardia was induced by atrial stimulation. Verapamil abolished sustained ventricular tachycardia in 1 of the 3 patients in whom this drug was administered. Hypotheses are made on the electrophysiological mechanisms of the arrhythmias and clinical implications are listed.
mesh_terms: D000328:Adult; D000368:Aged; D001283:Atrioventricular Node / Q000503:physiopathology; D002037:Bundle-Branch Block / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography; D005260:Female; D006322:Heart Aneurysm / Q000503:physiopathology; D006325:Heart Atria / Q000503:physiopathology; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008945:Mitral Valve Prolapse / Q000503:physiopathology; D009203:Myocardial Infarction / Q000503:physiopathology; D013610:Tachycardia / Q000175:diagnosis / Q000503:physiopathology*; D014700:Verapamil / Q000627:therapeutic use
chemical_list: D014700:Verapamil