Clinical estimation of left and right ventricular volume with open chest compared with transesophageal echocardiography and fast-response thermodilution

Abstract

A clinical measure--inspection of the relation of the heart (acute margin) to the diaphragm--has shown a strong positive correlation to transesophageal echocardiographic (TEE) determination of left ventricular end-diastolic area (LVEDA) during weaning from cardiopulmonary bypass (CPB). The present study examines the correlation between right ventricular end-diastolic volumes (RVEDV) before and after CPB when using the same clinical measure of left ventricular dimension. Prospective study. Operating room, university hospital. Patients scheduled for elective coronary artery bypass grafting. After induction of anesthesia and endotracheal intubation, a transesophageal echo-probe was inserted. A pulmonary artery right ventricular ejection fraction/volumetric TD catheter was placed in the pulmonary artery. Before going on CPB, a mark was made with cautery at the line of contact between the acute margin and the diaphragm. After CPB, the patients were transfused to the same level. At these two times, TEE recordings of the LVEDA and hemodynamic measurements including calculations of RVEDV were obtained. The LVEDA before and after CPB showed a positive correlation, r = 0.81, p < 0.001. The RVEDV after CPB showed a weak correlation, r = 0.54, p < 0.05, to RVEDV before CPB. There were no significant changes in right ventricular (RV) wall tension calculated as right atrial pressure x RVEDV and pulmonary artery systolic pressure x right ventricular end-systolic volume products. The only significant change regarding hemodynamic parameters was a decrease in mean arterial pressure. It is concluded that there is only a weak correlation regarding RVEDV before and after CPB when the patient is transfused to the line of contact, whereas this clinical measure correlates well with LVEDA.