Systolic Time Intervals in Severe Aortic Valve Disease

Abstract

Systolic time intervals were recorded in 25 consecutive patients before and after aortic valve surgery. Ten patients with dominant aortic stenosis (AS) and 10 with dominant aortic insufficiency (AI) received a Starr-Edwards prosthesis; five underwent repair procedures for AS or subaortic lesions. Before operation, the mean rate-corrected left ventricular ejection time (LVET_c) was prolonged; postoperatively LVET_c decreased significantly. Conversely, preoperative mean rate-corrected preejection period (PEP_c) was short and increased postoperatively. Serial measurement of LVET_c in a patient who had two aortic valve replacements suggested its value in quantitating prosthetic malfunction. In AS, preoperative LVET_c correlated closely with cardiac index; normal ejection times were associated with the most severely depressed flows. Preoperative variations in PEP_c in AS related inversely to the first derivative of the left ventricular pressure curve (maximal LV dp/dt). In AI, PEP_c correlated with the quotient: [see Equation in PDF File] where Adbp — LVed = transaortic end-diastolic pressure difference (aortic diastolic pressure minus LV end-diastolic pressure), and dp/dt = maximal LV dp/dt. This study identifies the flow and pressure parameters which correlate with abnormalities of PEP_c and LVET_c with severe AS and AI. The sensitivity of this technique to the hemodynamic changes of corrective surgery makes it a potentially useful noninvasive means to measure prosthetic valve function.