Amin Anish, Davis Michael, Auseon Alex
Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University College of Medicine, 473 W. 12th Avenue, Davis Heart Lung Research Institute, Suite 200, Columbus, OH 43210, USA.
Eur J Echocardiogr. 2009 Jan;10(1):173-4. doi: 10.1093/ejechocard/jen212. Epub 2008 Jul 29.
A 53-year-old woman with a history of hypertension was referred for an echocardiogram by her primary care physician after an unspecified abnormal ECG. The echocardiogram showed normal left ventricular size and function; however, an isolated cleft posterior mitral valve leaflet was identified with concomitant bileaflet prolapse and mild mitral regurgitation. She was subsequently referred to a cardiologist for clinical evaluation. Cleft mitral valve leaflet (CMVL) is an uncommon congenital cause of mitral regurgitation. Clefts, defined as slit-like holes or defects, are hypothesized to be a result of incomplete expression of an endocardial cushion defect which most commonly involves the anterior mitral valve leaflet with a paediatric incidence of 1:1340. Clefts affecting only the posterior mitral valve leaflet are extremely rare with only four cases being reported in the medical literature. Important co-existing anomalies with either posterior and/or anterior CMVL include counterclockwise rotation of the papillary muscles, the presence of an accessory papillary muscle or mitral valve leaflet, atrial septal defects, and mitral valve prolapse. Regurgitation from CMVL can lead to important physiological and anatomical changes within the cardiac system. Regurgitation results from blood flow directly through the cleft itself or from malcoaptation from accessory chordae with or without papillary muscle distortion. Significant chronic mitral regurgitation elevates left atrial filling pressures and leads to chamber enlargement and eccentric left ventricular hypertrophy. Early detection through two-dimensional echocardiography can provide accurate anatomical images of the various mitral valve structures and identify associated congenital anomalies. Early surgical correction is preferred before mitral regurgitation causes unfavourable remodelling. Most mitral valve cleft defects can easily be repaired by suturing the edges of the cleft. If a cleft resection leads to limited residual valve tissue, the leaflet of the mitral valve can be reconstructed using an autologous pericardial patch pre-treated with buffered glutaraldehyde. Posterior CMVL is an uncommon but clinically important cause of mitral insufficiency. Early recognition of this rare clinical entity and possible co-existent anomalies can identify the patients who would benefit from surgical intervention before compensatory left ventricular remodelling and contractile dysfunction develop.
一名有高血压病史的53岁女性，在一次未明确的异常心电图检查后，被其初级保健医生转诊进行超声心动图检查。超声心动图显示左心室大小和功能正常；然而，发现二尖瓣后叶有孤立性裂隙，伴有双叶脱垂和轻度二尖瓣反流。随后她被转诊给心脏病专家进行临床评估。二尖瓣叶裂（CMVL）是二尖瓣反流的一种罕见先天性病因。裂隙被定义为狭缝状的孔或缺陷，据推测是心内膜垫缺损不完全表达的结果，最常见于二尖瓣前叶，小儿发病率为1:1340。仅影响二尖瓣后叶的裂隙极为罕见，医学文献中仅报道了4例。与后叶和/或前叶CMVL同时存在的重要异常包括乳头肌逆时针旋转、副乳头肌或二尖瓣叶的存在、房间隔缺损以及二尖瓣脱垂。CMVL引起的反流可导致心脏系统内重要的生理和解剖学变化。反流是由于血流直接通过裂隙本身，或由于副腱索的对合不良，伴有或不伴有乳头肌扭曲。严重的慢性二尖瓣反流会升高左心房充盈压，导致心房扩大和偏心性左心室肥厚。通过二维超声心动图早期检测可以提供二尖瓣各种结构的准确解剖图像，并识别相关的先天性异常。在二尖瓣反流导致不良重塑之前，早期手术矫正更为可取。大多数二尖瓣裂隙缺损可以通过缝合裂隙边缘轻松修复。如果裂隙切除导致剩余瓣膜组织有限，可以使用经缓冲戊二醛预处理的自体心包补片重建二尖瓣叶。后叶CMVL是二尖瓣关闭不全的一种罕见但临床上重要的病因。早期识别这种罕见的临床实体以及可能同时存在的异常，可以确定那些在代偿性左心室重塑和收缩功能障碍发展之前将从手术干预中获益的患者。
