Immediate effects of aortic valve replacement on left ventricular functionand its determinants

Replacement of the aortic valve exposes the left ventricle to myocardial is chaemia and imposes on it abrupt changes in loading conditions and geometry . We studied the immediate changes in the left ventricular function of pati ents undergoing aortic valve replacement by transoesophageal echocardiograp hy. Patients with aortic regurgitation responded to surgery with a decrease in global systolic function associated with a fall in preload. Patients wi th aortic stenosis showed an impairment in myocardial contractility and ven tricular filling, and their global systolic function did not improve despit e the marked reduction in afterload. This can be a consequence of inadequat e myocardial protection and intra-operative ischaemic injury of the hypertr ophic myocardium. Information provided by transoesophageal echocardiography contributes to optimal and individualized management of the period immedia tely after aortic valve replacement.