During a difficult arithmetic task, Type A men exhibited significantly greater reductions in T-wave amplitude compared to Type B men, suggesting excessive sympathetic stimulation of the myocardium.
Observational
Phasic changes in heart rate (HR) and electrocardiographic T-wave amplitude (TWA) were monitored in healthy Type A (coronary-prone) and Type B (non-coronary-prone) men during the performance of a difficult arithmetic task. Type As showed significantly greater reductions in TWA as compared to Type Bs, though no group differences were present in HR change. This pattern of results, wherein a significant Type A-B difference was observed in a phasic measure of ventricular performance (TWA), but not in one of supraventricular performance (HR), suggests that Type As experience excessive neurally mediated sympathetic stimulation of the myocardium during mental work.
Scher et al. (Sat,) conducted a observational in Healthy men. Difficult arithmetic task vs. Type B men was evaluated on Phasic changes in heart rate and electrocardiographic T-wave amplitude. During a difficult arithmetic task, Type A men exhibited significantly greater reductions in T-wave amplitude compared to Type B men, suggesting excessive sympathetic stimulation of the myocardium.
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