EFFECTS OF CALCIUM ON LEFT-VENTRICULAR FUNCTION EARLY AFTER CARDIOPULMONARY BYPASS

Objectives: Evaluation of the effects of intravenous CaCl2 on systolic and diastolic function early after separation from cardiopulmonary by pass (CPB) Design: Prospective study Setting: University hospital Part icipants: Twenty patients scheduled for elective coronary artery surge ry Interventions: Left ventricular (LV) pressures were measured with f luid-filled catheters. Data were digitally recorded during pressure el evation induced by tilt-up of the legs. Transgastric short-axis echoca rdiographic views of the LV were simultaneously recorded on videotape. Measurements were obtained before the start of CPB, 10 minutes after termination of CPB, after intravenous administration of CaCl2, 5 mg/kg , and 10 minutes later. Measurements and Main Results: Systolic functi on was evaluated with the slope (Ees, mmHg/mL) of the systolic pressur e-volume relation. Diastolic function was evaluated with the chamber s tiffness constant (Kc, mmHg/mL) of the diastolic pressure-volume relat ion. CaCl2 increased Ees from 2.62 +/- 0.46 to 5.58 +/- 0.61 (mean +/- SD), but induced diastolic dysfunction with an increase in Kc from 0. 011 +/- 0.006 to 0.019 +/- 0.007. These changes were transient and had disappeared within 10 minutes after administration of CaCl2. Conclusi ons: CaCl2 early after CPB transiently improved systolic function at t he expense of an increase in ventricular stiffness, suggesting tempora ry diastolic dysfunction. Copyright (C) 1997 by W.B. Saunders Company.