Relationship between systolic time interval measurements and the extent of regional ventricular asynergy in coronary artery disease.

Systolic time interval (STI) measurements were made in 44 patients with coronary artery disease: 38 had regional left ventricular (LV) asynergy, and the remaining 6 had normal ventricular contraction patterns on left ventricular angiography. There was a significant correlation between both the preejection period (PEP) (r = 0.70) and the PEP/LVET (LV ejection time) ratio (r = 0.66), with the extent of regional ventricular dysfunction measured quantitatively on the left ventricular angiogram (P less than 0.001). A PEP/LVET ratio greater than 0.50 was associated with ventricular asynergy involving more than 40% of the LV circumference at end diastole. STI measurements also correlated with ejection fraction but not with ventricular end diastolic pressure nor with the number of obstructed coronary arteries.