[Disorders of fascicular conduction following coronary surgery: etiology and clinical relevance].

: Seventy-one consecutive patients undergoing coronary artery bypass grafting (CABG) were studied prospectively. New fascicular conduction defects (FCD) were evident in 51 patients (72%) 1 h after cardioplegic cardiac arrest, in 40 patients (56%) after 2 h, in 29 patients (41%) on the first postoperative day, and in 14 patients (20%) on the seventh postoperative day. Right bundle branch block was the most common type of FCD, followed by left anterior hemiblock. FCD were related to longer aortic cross-clamp time, higher age (p less than 0.025), frequency of wall motion abnormalities (p = 0.033), the number of diseased (p = 0.007) and bypassed vessels (p less than 0.0005), a greater intra- (p = 0.018) and postoperative (p = 0.017) demand for catecholamines, a more complicated postoperative course (p = 0.005), and a longer stay in the intensive care unit (p less than 0.01). Ischemic damage to the conduction system during cardioplegic cardiac arrest appears to be the most likely explanation for new FCD after CABG. Severe coronary heart disease contributes to their development. Hence, adequate myocardial preservation is of crucial importance. FCD are associated with increased perioperative morbidity, according to other studies, also with poorer long-term prognosis, especially in case of a left bundle branch block. In this subset a closer follow-up may be indicated.