David T E
Division of Cardiovascular Surgery, Toronto Hospital, Ontario, Canada.
J Card Surg. 1994 Mar;9(2 Suppl):274-7. doi: 10.1111/j.1540-8191.1994.tb00940.x.
Mitral regurgitation (MR) may start during the acute phase of myocardial infarction and it may increase, decrease, or remain unchanged as the necrotic muscle is replaced by fibrous tissue and remodeling of the ventricle takes place. Acute infarction can cause MR because of rupture of papillary muscle (PM) head or dysfunction of the PM and underlying ventricular wall. When MR is due to rupture of a single PM head and the surrounding muscle is not extensively infarcted, it is possible to suture the PM head in place with pledget sutures or to use other techniques of repair of flair leaflets such as chordal transfer or chordal replacement. When MR is due to extensive necrosis of the PM and the ventricular wall, it is safer to replace the mitral valve with preservation of the chordae tendineae. Correction of MR by means of valve repair in patients with healed myocardial infarction is frequently possible when the cause of MR is determined by Doppler echocardiography. The most common cause of MR is incomplete closure of the mitral valve due to apical displacement of the PM. Prolapse of the leaflets is rare in patients with healed myocardial infarction. Mitral annuloplasty decreases or abolishes MR in most cases when lack of coaptation of the leaflets is the problem. Transient ischemia can also cause MR. Successful myocardial revascularization either by angioplasty or coronary artery bypass often cures episodic ischemic MR.
二尖瓣反流（MR）可能在心肌梗死急性期开始，并且随着坏死心肌被纤维组织替代以及心室发生重塑，其可能增加、减少或保持不变。急性梗死可因乳头肌（PM）头部破裂或PM及下方心室壁功能障碍而导致MR。当MR是由于单个PM头部破裂且周围心肌未广泛梗死时，可用带垫片缝线将PM头部缝合到位，或使用其他修复瓣叶的技术，如腱索转移或腱索置换。当MR是由于PM和心室壁广泛坏死时，保留腱索置换二尖瓣更安全。当通过多普勒超声心动图确定MR的病因时，对于心肌梗死已愈合的患者，通过瓣膜修复纠正MR通常是可行的。MR最常见的原因是PM向心尖移位导致二尖瓣关闭不全。在心肌梗死已愈合的患者中，瓣叶脱垂很少见。当问题是瓣叶对合不良时，二尖瓣环成形术在大多数情况下可减少或消除MR。短暂性缺血也可导致MR。通过血管成形术或冠状动脉搭桥成功实现心肌血运重建通常可治愈发作性缺血性MR。
