Phonocardiographic changes induced by neuropsychic stress

We studied the changes occurred in the electrocardiograms, phonocardiograms, apexocardiograms, carotid pulse tracings and blood pressure in 21 healthy men, range 18 to 45, before and during performing timed mental arithmetics. Besides well-known significant increase in heart rate, systolic blood pressure, differential blood pressure (no significant rise in diastolic blood pressure was observed) several phonocardiographic abnormalities were recorded: a significant increase in amplitude and number of vibrations of the early systolic ejection sound and a prominent fourth sound. In general the preexistent third sound diminished after mental stress. In young subjects--range 18 to 30--the ratio of preejection period versus ejection period was lower after mental stress as hyperkinetic conditions occurred whilst in adults the ejection period shortened. The detected phonocardiographic abnormalities reflected significant changes in contractility and compliance of myocardium and great vessels. These abnormalities may account for some cardiac dysfunction in patients with ischemic heart disease subjected to neuropsychic stress and may be misinterpreted for more severe pathological changes.