The effects of pathologic states on right and left ventricular function have been studied extensively. However, there have been few studies on the interrelations between right and left ventricular function in normal human subjects and in patients with disease. Respiratory effects on ventricular interrelations reflected by diastolic time, right or left ventricular systolic time and ventricular performance (pre-ejection period/ejection time ratio) were studied in 12 normal subjects and 15 patients with a normal pressure-large shunt atrial septal defect. Simultaneous pulmonary artery (intracardiac manometer recordings) and left ventricular external recordings were performed in both groups. Left ventricular diastolic time increased with inspiration in the normal subjects and decreased in the patients with atrial septal defect (12.6 +/- 2.39 [1 SE] versus -13.4 +/- 3.48 ms, p less than 0.001). Left ventricular systolic time and ejection time decreased with inspiration in the normal group and remained unchanged in the patient group (-7.6 +/- 0.95 versus -0.9 +/- 0.77 ms, p less than 0.001 and -10.4 +/- 1.09 versus -1.7 +/- 0.80 ms, p less than 0.001, respectively). Left ventricular pre-ejection period/ejection time ratio increased with inspiration in the normal subjects and remained unchanged in the patients with atrial septal defect (0.03 +/- 0.008 versus 0 +/- 0.01, p less than 0.01). Right ventricular diastolic time decreased with inspiration in normal and patient groups (-8.8 +/- 1.6 versus -17 +/- 3.87 ms).(ABSTRACT TRUNCATED AT 250 WORDS)