In 49 patients suffering of heart diseases we have studied the changes of radiologic cardiac measurements and systolic time intervals (STI) in the four functional classes of the New York Heart Association (NYHA) classification, investigating also the existence of any relationship between these different parameters. Only the patients in functional classes 3rd and 4th showed significant changes in STI and radiologic measurements as compared to the control group. Moreover, a significant negative correlation has been observed between relative heart volume and left ventricular ejection time (LVET) (r = 0.69, P less than 0.001) and LVETc (r = 0.82, P less than 0.001) and a positive correlation between relative heart volume and pre-ejection period (PEP) (r = 0.59, P less than 0.01) and PEP/LVET ratio (r = 0.75, P less than 0.001). These results seem to demonstrate that relative heart volumetry is a fairly accurate index of the cardiac conditions in non valvular heart diseases.