Clinical characteristics of rapid atrial fibrillation preceding ventricular tachycardia

Spontaneous degeneration of rapid atrial fibrillation (AF) to ventricular fibrillation has been documented in patients with hypertrophic cardiomyopathy (HCM) and Wolff-Parkinson-White (WPW) syndrome. However, the importance of rapid AF as a triggering factor leading to sustained ventricular tachycardia (VT) in patients with other structural heart diseases is unknown. The purpose of this study was to characterize patients who developed VT following paroxysmal or chronic AF with a rapid ventricular response. The mode of VT initiation and clinical characteristics were reviewed in 8 patients (7 men, 1 woman age 64 +/-9 years) with monomorphic VT preceded by rapid AF (6 paroxysmal, 2 chronic). All patients developed monomorphic VT (mean cycle length 285 +/- 31 ms) with syncope only after rapid, but hemodynamically stable, AF (mean heart rate 153 +/- 30 beats/min) without acute ischemia or exacerbation of heart failure. There was no significant variation in R-R intervals of the AF preceding VT. All patients had structural heart disease other than HCM with a mean left ventricular ejection fraction of 41 +/- 12%. During the 807 +/- 201 days of follow-up, VTs did not recur in 7 patients. Sinus rhythm was maintained in all patients who received amiodarone. Rapid AF may be an important triggering factor of monomorphic VT in some patients with moderately impaired cardiac function.