Mean electromechanical delta P/ delta t and systolic time intervals in coronary artery disease

Mean electromechanical deltaP/deltat and systolic time intervals were measured in 30 patients with coronary artery disease. Total electromechanical systole (QS2), left ventricular ejection time (LVET) and preejection period (PEP) were measured and PEP/LVET calculated. Systolic time intervals were obtained noninvasively. Mean electromechanical deltaP/deltat was calculated by means of systemic diastolic blood pressure, pulmonary wedge pressure and PEP. Left ventricular ejection fraction (EF), pulmonary wedge pressure and stroke index were determined by catheterization and left ventriculography. PEP (r = -0.69) and PEP/LVET (r = -0.68) were better correlated to EF than mean electromechanical delatP/deltat (r = 0.63). Patients with previous myocardial infarction were found to have significantly longer PEP (P less than 0.02) and higher PEP/LVET (P less than 0.01) than patients without infarction. Neither of the methods showed significant differences between the groups of patients with 1-, 2- and 3-vessel disease. Although systolic time intervals cannot be used in predicting invasive measurements such as EF, the findings indicate that PEP and PEP/LVET may be useful supplement to clinical examination in evaluating left ventricular function in coronary artery disease.