[Changes in hemodynamic indices during perfusion with pulsatile and steady currents in aortocoronary bypass surgery]

Hemodynamic parameters were compared in 28 patients with ischemic heart disease subject to cardiopulmonary bypass surgery with non-pulsatile (group 1) and pulsatile flow (group 2). Systolic, diastolic and mean blood pressure (MBP) was assessed, total peripheral vascular resistance (TPVR) was calculated, esophageal, rectal and skin temperature was measured. Volumetric perfusion rate was the same in both groups. Pulse pressure was maintained at the level of 35 mmHg. MBP at the stage of hypothermia plateau and during warming decreased in both groups. It was significantly lower in group 1 at the beginning of warming and during clamp relief from the aorta. At the end of cooling period TPVR was lower with the use of pulsatile than non-pulsatile flow. It increased drastically towards the end of hypothermia plateau in group 1. During clamp relief from the aorta TPVR values did not significantly differ from baseline in group 2 and remained high in group 1. The warming rate happened to be greater in pulsatile than in non-pulsatile flow.