[Right and left ventricular systolic time intervals in patients with atrial septal defect measured by the ultrasonic...

Noninvasive measurement of right and left ventricular systolic time intervals (STIs) was made utilizing ultrasonic Doppler method in 35 patients with secundum atrial septal defect (ASD) to evaluate their hemodynamic states. Using the Doppler signals relating to the opening and closure of the pulmonary and aortic valves, both right and left ventricular preejection periods (RPEP, LPEP) and ejection times (RVET, LVET) were measured. The same studies were carried out in 50 control healthy subjects. In patients of ASD without pulmonary hypertension (mean pulmonary arterial pressure less than 20 mmHg), RPEP did not differ significantly from that of healthy subjects, while RVET was significantly prolonged reflecting right ventricular volume overloading. In patients with pulmonary hypertension (mean pulmonary arterial pressure greater than or equal to 20 mmHg), RPEP was prolonged and RPEP/RVET was significantly higher than those in healthy subjects. These two parameters were correlated well with pulmonary arterial pressure. In both groups LVET was shorter and LPEP/LVET was larger than those of normal, suggesting low output state of the left ventricle. In 5 surgical cases, LVET was prolonged and LPEP/LVET decreased after operation, while the right ventricular STIs did not change significantly. With the pulmonary to systemic flow ratio (Qp/Qs), only RVET/LVET was correlated significantly, but with poor correlation coefficient (r = 0.47, p less than 0.01). These data may suggest that noninvasive measurement of combined right and left ventricular STIs is useful to assess the hemodynamic states of ASD, especially for evaluation of associated pulmonary hypertension.