SYSTOLIC ARTERIAL-PRESSURE RECOVERY AFTER VENTRICULAR-FIBRILLATION FLUTTER IN HUMANS

Although the elective induction of cardiac arrest for implantable defi brillator insertion under general anesthesia is widely used, the hemod ynamics of recovery of arterial blood pressure after cardiac arrest is not well-defined. Accordingly, the time course of recovery of systoli c arterial pressure was studied in seven patients during the repetitiv e induction of ventricular fibrillation (n = 6) or ventricular flutter (n = 1). The mean number of episodes of cardiac arrest was 7 +/- 2, a nd the mean drop in systolic pressure was 84 +/- 16 mmHg. The mean rec overy time for systolic pressure was 10 +/- 6 seconds, the average sys tolic pressure recovery rate was 13 +/- 14 mmHg/sec, and the mean perc ent systolic pressure recovery was 94 % +/- 9%. A negative logarithmic relation was found to exist between the rate of systolic arterial pre ssure recovery and the duration of ventricular fibrillation or flutter with a correlation coefficient of 0.68 to 0.97 (P < 0.05) in five of the seven patients. A linear relation between the time for systolic pr essure recovery and duration of asystole was also defined. These resul ts are consistent with the view that prolongation of ventricular fibri llation or flutter increases the duration of arterial pressure recover y through a negative effect on left ventricular contractility. Increas ed understanding of these relations may lead to increased safety of im plantable defibrillator insertion.