Digitalis-associated cardiac mortality after myocardial infarction.

The effect of digitalis therapy on 4-month posthospital cardiac mortality was investigated in 812 patients who survived the hospital phase of acute myocardial infraction. A stepwise multiple logistic regression analysis was used to identify variables associated with increased mortality and to adjust for differences in confounding variables between digitalis and nondigitalis patients. The major 4-month mortality (10 of 26 patients [38.5%]) occurred in digitalis-treated patients with congestive heart failure in the coronary care unit and complex ventricular premature depolarizations (VPDs) on the predischarge Holter recording. Logistic analyses that controlled for confounding variables indicated that digitalis use contributed to the increased mortality rate in this high-risk subset. The predicted mortality difference due to digitalis in patients with congestive heart failure and complex VPDs, adjusted for relevant nondigitalis risk factor variables, was 30% (90% confidence interval 18-42%). This retrospective study suggests that digitalis use increases the early posthospital mortality of myocardial infarction patients with combined electrical and mechanical dysfunction.

Frequency and complexity of ventricular ectopic beats in the posthospital phase of myocardial infarction.

This study is a descriptive report of the occurrence of ventricular arrhythmias in a large, prospectively designed follow-up study of postcoronary patients. Six-hour Holter recordings were obtained on 954 postinfarction patients prior to hospital discharge and at 4 (n = 837), 8 (n = 762), 12 (n = 713), and 24 (n = 487) months post-discharge. Ventricular ectopic beats (VEB) were quantitated by frequency and patterns at each recording, and antiarrhythmic medication usage was recorded. The proportion of patients wtih each VEB frequency (any, less than 9.9/hour, 10 - 19.9/hour, greater than or equal to 20/hour) increased progressively during the 24-month follow-up, with the most significant increase in the interval between baseline and the four-month follow-up recording. Significant (p less than 0.01) associations were found between VEB frequency greater than or equal to 20/hour and almost all VEB patterns for each follow-up; no significant associations were found between VEB prematurity (RR'/QT less than or equal to 1.00) and any of the VEB patterns. Among the survivors, the utilization of diuretics and beta blockers increased (p less than 0.01) and antiarrhythmic agents declined (p less than 0.01) between predischarge and all subsequent follow-up visits. The significance of these findings is discussed.

Clinical significance of ventricular ectopic beats in the early posthospital phase of myocardial infarction.

The clinical significance of ventricular ectopic beats in the posthospital phase of myocardial infarction was studied in 272 patients aged 65 years or less who were followed up for 1 year after the infarction. Ventricular ectopic beats, identified in 6 hour electrocardiographic tape recordings, obtained before hospital discharge (study 1) and 5 months after discharge (study 2) increased in frequency and complexity in the 5 month interval. Ventricular ectopic beats at a rate of 20 or more per hour recorded before discharge were associated with complex ventricular ectopic patterns in the same 6 hour recording and with frequent (20 or more per hour), early cycle and bigeminal patterns in recordings mad 5 months later. Analysis with log-linear modeling indicated that the occurrence of complex ventricular ectopic beats at follow-up examination was associated with the concomitant use of antiarrhythmic agents,but not with use of digitalis, propranolol or tranquilizers. A ventricular ectopic beat frequency of 20 or more per hour at discharge was associated with increased (P less than 0.05) cardiac mortality in the initial 0 to 4 months after discharge but not in the subsequent 8 months; ectopic beats recorded in the 5 month follow-up study were not associated with increased cardiac mortality in the subsequent 5 to 12 months. The prognostic significance of ventricular ectopic beats is discussed in the light of these findings.