[Changes in left ventricular hemodynamics and contractility and significance of various reperfusion phase times in recurrent short duration ischemia in the human]

Abstract

The time courses of left ventricular systolic (LVSP) and enddiastolic (EDP) pressures as well as changes in peak dp/dtmax and peak dp/dtmin using high-fidelity-tip catheters were studied in 35 out of 179 consecutive patients undergoing elective percutaneous transluminal angioplasty (PTCA) of the left anterior descending artery (LAD). Only patients with global and regional normal left-ventricular function and without collateral filling of the target vessel in the diagnostic angiograms were included. Occlusion time of the LAD was 50 and 60 s during each cycle. Reperfusion time between each vessel occlusion was 60 s in 15 patients and 180 s in 20 patients. During every ischemic period identical significant decreases of LVSP (p less than 0.005), peak dp/dtmax (p less than 0.001), and peak dp/dtmin (p less than 0.001) and significant increases of EDP (p less than 0.001) were documented. The maximum of hemodynamic changes in every patient was within the first 20 s after vessel occlusion. With a reperfusion period of 60 s LVSP and EDP did not return to basic level and the difference reached statistical significance (p less than 0.05) during the fourth occlusion. This could not be documented when the reperfusion period lasted 180 s. For clinical implications a reperfusion time of 180 s between consecutive repeated short periods of ischemia during PTCA could be recommended.