[Conduction disorders after aortic valve replacement. Apropos of 200 cases].

The following points become apparent after the study of 200 cases of aortic valve replacement:--Conduction defects are very common after this type of surgery, affecting one in three patients in this series;--Above all, the frequency of conduction defects of the left bundle branch (2/3 cases) must be underlined. They are much more common than complete atrioventricular block, bifascicular block or isolated right bundle branch block;--Diagnosed immediately after operation in almost all cases, regression is common (50%) especially of left anterior hemiblock;--The long term prognosis is good. There was no long or short term mortality due to this cause in this series;--Apart from traumatic lesions which are difficult to avoid when the aortic orifice is calcified, ischaemia of the conduction pathways due to insufficient myocardial protection probably plays a role in the aetiology of these conduction defects.