Iatrogenic Complications During the Diagnostic Work-Up of an Inflammatory Cardiomyopathy

Abstract A 72-year-old woman was admitted for acute heart failure. The echocardiography revealed moderate depression of the left ventricular ejection fraction. Coronary disease was excluded by coronarography. Cardiac magnetic resonance showed predominantly left ventricular septal hypertrophy and severe depression of the left ventricular systolic function. There was also a bright, multifocal and patchy late gadolinium enhancement with subendocardial, mesocardial and subepicardial involvement, suggestive of sarcoidosis. Biochemical study, thoracic computed tomography and positron emission tomography were inconclusive for extra-cardiac sarcoidosis. Therefore, an endomyocardial biopsy was performed. The procedure was complicated by the development of complete atrioventricular block, requiring implantation of a cardiac resynchronization pacing device. A few days after device implantation, the patient developed fever. The echocardiography revealed extensive vegetations, and thus the diagnosis of a device-associated infective endocarditis was made. Even though antibiotic therapy was promptly started, the patient ended up dying. Biopsy results revealed lymphocytic myocarditis. This case is paradigmatic because it shows how the etiologic diagnosis of dilated cardiomyopathy can be challenging. Non-invasive diagnostic exams may not provide a definite diagnosis, requiring an endomyocardial biopsy. However, the benefits versus risks of such procedure must always be carefully weighted.

摘要 一名72岁女性因急性心力衰竭入院。超声心动图（echocardiography）显示左心室射血分数中度降低。冠状动脉造影（coronarography）排除冠状动脉疾病。心脏磁共振（cardiac magnetic resonance）检查提示以左心室室间隔肥厚为主要表现，且左心室收缩功能严重减退。同时可见多发、斑片状的明亮延迟钆增强（late gadolinium enhancement）显像，累及心内膜下、心肌中层及心外膜，高度提示结节病。生化检测、胸部计算机断层扫描（computed tomography）与正电子发射断层扫描（positron emission tomography）均未能明确心脏外结节病的诊断。遂为患者行经心内膜心肌活检（endomyocardial biopsy），该操作并发完全性房室传导阻滞（complete atrioventricular block），需植入心脏再同步化起搏装置（cardiac resynchronization pacing device）。装置植入数日后，患者出现发热，超声心动图显示广泛瓣膜赘生物，故确诊为起搏装置相关感染性心内膜炎（infective endocarditis）。尽管及时启动抗生素治疗，患者最终仍不治身亡。活检病理结果提示淋巴细胞性心肌炎（lymphocytic myocarditis）。本病例具有典型示范意义，因其清晰展现了扩张型心肌病（dilated cardiomyopathy）的病因诊断颇具挑战性：无创性检查往往无法提供明确诊断，需依赖心内膜心肌活检。然而，此类操作的获益与风险始终需审慎权衡。