Variability of heart rate, P-R, QRS and Q-T durations in twins.
During a cardiovascular risk factor study, electrocardiograms were done on 355 sets of middle-aged male monozygotic and dizygotic twins. Potential genetic variability in ventricular rate and P-R, QRS, and Q-T duration was investigated using classical statistical twin methodology. Significant genetically determined variability was found for ventricular rate and P-R interval. These findings suggest that heart rate and, to a lesser extent, atrial depolarization are under genetic control with 54% and 34%, respectively, of the variation among individuals explained by heredity.
D000328:Adult; D004562:Electrocardiography; D005260:Female; D005823:Genetics; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D014427:Twins; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic