肥厚型心肌病合并感染性心内膜炎五例

Infective endocarditis in patients with hypertrophic obstructive cardiomyopathy： five cases report

目的探讨肥厚型梗阻性心肌病患者合并感染性心内膜炎的临床特征。方法收集我院2000年1月至2010年12月诊断的感染性心内膜炎患者296例，其中肥厚型心肌病合并感染性心内膜炎的患者共5例，分析其临床资料和随访情况。结果5例合并感染性心内膜炎的肥厚型梗阻性心肌病占全部感染性心内膜炎病例的1．69％（5／296）。其中4例为左心室流出道梗阻，流出道压力阶差36～140mmHg（1rnmHg=0．133kPa），左心房增大44～68mm；1例右心室流出道心肌非对称性肥厚梗阻，右心室流出道压力阶差164mmHg，右心房增大56mm×53mm。5例患者血培养均为链球菌感染，其中1例术后瓣膜赘生物培养出屎肠球菌。5例患者分别进行了2～4次超声心动图或经食管超声心动图才发现赘生物。赘生物部位为单纯二尖瓣2例，主动脉瓣合并二尖瓣1例，二尖瓣合并三尖瓣1例，右心室流出道1例。4例左心室流出道梗阻的患者二尖瓣均存在收缩期前向运动（SAM征阳性），发生轻至重度关闭不全并发现赘生物。5例患者经敏感抗生素治疗后感染得到控制，1例反复发生周围动脉栓塞早期手术，1例择期手术治疗。除1例失访外，其余4例患者随访1～6年，感染性心内膜炎无复发。结论肥厚型梗阻性心肌病是感染性心内膜炎的危险因素，对流出道严重梗阻且伴有瓣膜损伤的患者，应采取必要措施预防心内膜炎的发生。

Objective To analyze the clinical characteristics of infective endocarditis in patients with hypertrophic obstructive cardiomyopathy. Methods Clinical characteristics from 5 patients with infective endocarditis and hypertrophic obstructive cardiomyopathy hospitalized from January 2000 to December 2010 in our hospital were analyzed. Results Four patients were diagnosed with left ventricular outflow tract obstructive cardiomyopathy with outflow pressure gradient from 36 to 140 mm Hg（ 1 mm Hg = 0. 133 kPa） and left atrial size 44 - 68 ram. Another patient was diagnosed as ventricular hypertrophic cardiomyopathy with significant right-ventricular outflow tract hypertrophy （30 mm） , high pressure gradient （ 164 mm Hg） and enlarged fight atrial （56 mm x53 mm）, there was a 17 mm x8 mm vegetation on rightventricular outflow tract in this patient. Blood cultures were positive for streptococcus viridans in all five patients, and enterococcus faeeium was revealed in one aortic valve vegetation culture. Transthoracic echocardiogram was performed 2 - 4 times for each patient, the vegetations of two patients was detected only by transesophageal echocardiography. The mitral valve vegetation was detected in two patients, the aortic and mitral valve vegetations were detected in one patients, mitral and tricuspid vegetations in one patient and right ventricular outflow tract vegetation in one patient. The four hemodynamically stable patients were successfully treated with antibiotic therapy, one patient received urgent surgery （ replacement of the aortic and mitral valve as well as septal myectomy）. All patients recovered and follow-up （1 -6 years） was available in 4 patients and no complication was observed. Conclusion The risk of infective endocarditis complicating hypertrophic obstructive cardiomyopathy is the highest in patients with both outflow obstruction and marked valve insufficiency, these patients should receive prophylactic antibiotic therapy during procedures that predispose to infective endocarditis.