Circulation
-
Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
Randomized, double-blind comparison of intravenous amiodarone and bretylium in the treatment of patients with recurrent, hemodynamically destabilizing ventricular tachycardia or fibrillation. The Intravenous Amiodarone Multicenter Investigators Group.
After several days of loading, oral amiodarone, a class III antiarrhythmic, is highly effective in controlling ventricular tachyarrhythmias; however, the delay in onset of activity is not acceptable in patients with immediately life-threatening arrhythmias. Therefore, an intravenous form of therapy is advantageous. This study was designed to compare the safety and efficacy of a high and a low dose of intravenous amiodarone with bretylium, the only approved class III antiarrhythmic agent. ⋯ Bretylium and amiodarone appear to have comparable efficacies for the treatment of highly malignant ventricular arrhythmias. Bretylium use, however, may be limited by a high incidence of hypotension.
-
Left ventricular hypertrophy has been established as an independent risk factor for the development of cardiovascular morbidity and mortality. It is clear that left ventricular mass increases during childhood and adolescence with body growth. The extent to which other factors, such as obesity, stage of sexual maturation, and level of blood pressure, determine left ventricular mass has been controversial. ⋯ This study provides an opportunity to separate the effects on left ventricular mass of lean body mass resulting from linear growth from those of fat mass resulting from obesity. Lean body mass, fat mass, and systolic blood pressure all have a statistically significant independent association with left ventricular mass, suggesting that all three play an important biological role in determining left ventricular mass. However, fat mass and systolic blood pressure have only a small impact on left ventricular mass. This indicates that fat mass and blood pressure would be expected to be of only minor clinical importance in determining left ventricular mass in normal children and adolescents.