Assessment of mitral valve function at operation and the prevention of systemic embolism.

When assessing the function of the mitral valve at operation by palpation or inspection, the surest way to prevent systemic (cerebral) embolism is to have the ascending aorta occluded by a clamp. A technique is described which allows safe assessment of mitral valve function by aortic root and left ventricular perfusion, giving a beating-heart preparation with the aorta cross-clamped. This method has been in successful use for more than two years and has been found particularly useful in the accurate repair of cleft mitral valves in atrioventricular defects (ostium primum defects and atrioventricular canal).