Sex differences in cardiac function of a group of young adults.

Ballistocardiogram and carotid pulse recordings were made on a group of healthy young men and women aged 25--35 years. The recordings were subjected to a newly developed procedure for feature recognition and measurement (FRAM) by digital computer. Results from the FRAM were grouped according to sex of subjects tested and inspected for statistically significant differences in mean values of the many separate items calculated. There were marked differences between the men and women in those items most closely related to initial acceleration of blood in the aorta. It was hypothesized that the hyperdynamic values from the males were indicative of intrinsic functional differences between their myocardia and that of the females.