DETERMINANTS OF THE SPONTANEOUS ECTOPIC ACTIVITY IN REPETITIVE MONOMORPHIC IDIOPATHIC VENTRICULAR-TACHYCARDIA

[摘要] Twenty-four hour ambulatory electrocardiographic taped recordings of 30 patients (16 men and 14 women, mean 42 .+-. 17 years) with repetitive monomorphic idiopathic ventricular tachycardia were analyzed using a new computerized system designed to study 15 RR cycles and mean heart rate of the 3 minutes preceding any defined event. The mean (.+-. SD) number of events analyzed per patient in 24 hours was 610 .+-. 483 for single premature ventricular complexes, 622 .+-. 490 for couplets, 260 .+-. 411 for runs of 3 complexes, 186 .+-. 476 for runs of 4, 108 .+-. 173 for runs of 5, 82 .+-. 129 for runs of 6 to 10 and 83 .+-. 116 for runs of more than 10 complexes. The heart rate was faster before runs of ventricular tachycardia than before isolated extrasystoles (p < 0.01) and a positive linear correlation was observed between the mean preceding heart rate and the type of extrasystolic activity, the length of the runs increasing with increasing preceding heart rate (r = 0.98, p < 0.001). A long RR interval just before the occurrence of runs was present in 77% of the cases (23 of 30) with or without an oscillatory pattern of RR intervals due to bigeminy or trigeminy, and the length of the runs correlated positively with the duration of this long preceding diastole (r = 0.90, p < 0.05). The coupling interval of the first extrasystole (RV1) was longer for runs than for single extrasystoles in 60% of the cases, and in this subgroup of patients the length of the runs was positively related to the RV1 value (r = 0.98, p < 0.001). From this study it is concluded that three major determinants of spontaneous ectopic activity are present in repetitive monomorphic idiopathic ventricular tachycardia: the preceding mean heart rate (adrenergic dependence) the length of the RR cycle preceding the initial extrasystole (rate dependence) and the coupling interval of the first extrasystole. These observations suggest that a mechanism of triggered activity may be responsible for the repetitive activity in this particular type of ventricular arrhythmia.

[发布日期] 1986-06-01