Cardiovascular changes associated with sexual arousal and orgasm in men

Indices of cardiovascular function were measured in seven men while they masturbated to ejaculation. Cardiac electrical activity, respiration, finger pulse, and anal contractions were monitored. Orgasm was determined by the onset of anal contractions. While there were marked individual differences, reliable changes were observed in heart rate, pulse transit time, pulse amplitude, and pulse rise velocity during masturbation. In addition, we were able to identify specific changes in some of these measures during the few seconds prior to the onset of anal contractions, during these contractions, and after their termination. Based upon these observations, we propose a characterization of the autonomic activity associated with sexual arousal and orgasm in men which differs from that currently provided in the literature. Specifically, we propose that the critical autonomic event associated with orgasm is an acute increase in parasympathetic activity in the presence of elevated sympathetic tone.