Changes in Left Ventricular Afterload Following Weaning from Cardiopulmonary Bypass Proved Useful for the Anesthetic Management of Aortic Valve Replacement: A Case Report.

During aortic valve replacement, after weaning from the cardiopulmonary bypass (CPB), systemic vascular resistance, which constitutes the left ventricular afterload, fluctuates significantly due to systemic inflammatory responses, changes in body temperature, and the use of vasoconstrictors. Particularly in hypertrophic hearts that have adapted to increased afterload for a long time, a sudden increase in afterload following weaning from CPB carries a risk of inducing left heart failure or prosthetic valve failure. With mechanical prosthetic valves, a slight physiological regurgitation is observed during valve closure. In this case, by using pulse Doppler echocardiography and transesophageal echocardiography to monitor this physiological regurgitation in real time, we were able to rapidly assess changes in left ventricular afterload and accurately manage the administration of vasoactive agents; we therefore report on the clinical course of this case.