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 bypass (CPB) Design: Prospective study Setting: University hospital Participants: Twenty patients scheduled for elective coronary artery surgery Interventions: Left ventricular (LV) pressures were measured with fluid-filled catheters. Data were digitally recorded during pressure elevation induced by tilt-up of the legs. Transgastric short-axis echocardiographic 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 function was evaluated with the slope (Ees, mmHg/mL) of the systolic pressure-volume relation. Diastolic function was evaluated with the chamber stiffness constant (Kc, mmHg/mL) of the diastolic pressure-volume relation. 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. Conclusions: CaCl2 early after CPB transiently improved systolic function at the expense of an increase in ventricular stiffness, suggesting temporary diastolic dysfunction. Copyright (C) 1997 by W.B. Saunders Company.