Department of Neurology, Mayo Clinic, Rochester, MN.
Department of Neurology, Mayo Clinic, Rochester, MN; Division of Neurology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada.
Mayo Clin Proc. 2020 Oct;95(10):2144-2149. doi: 10.1016/j.mayocp.2020.03.032. Epub 2020 Aug 14.
To characterize the cardiorespiratory abnormalities in patients with necrotizing autoimmune myopathy (NAM).
Cardiopulmonary features of patients with NAM evaluated in our neuromuscular clinic (January 1, 2004, to September 20, 2018) were reviewed retrospectively with respect to autoantibody status and history of cardiac disease. Clinical characteristics and laboratory findings were compared among patient subgroups.
We identified 109 patients with NAM: 36 anti-3-hydroxy-3-methylglutaryl coenzyme A reductase autoantibody (anti-HMGCR Ab)-positive, 18 anti-signal recognition particle antibody (anti-SRP Ab)-positive (3 dual anti-HMGCR/anti-SRP Ab-positive), and 58 seronegative. Median age at diagnosis was 60 years (range, 18-86 years). Forty-three patients had dyspnea at presentation and 32 patients had preexisting risk for cardiac disease (10 coronary artery disease and 28 hypertension). The electrocardiogram was abnormal in 55 of 86 patients (33 without cardiac risk factors), including prolonged corrected QT interval (QTc) (n=31), conduction blocks (n=19), and atrial or ventricular ectopic beats (n=10). Echocardiography was abnormal in 34 of 72 patients, including 19 of 45 without preexisting cardiac disease risks. Echocardiographic abnormalities included left ventricular diastolic dysfunction (n=31) and systolic dysfunction (n=8). The left ventricular diastolic dysfunction improved in 4 of 11 patients after treatment. Pulmonary function testing showed changes suggestive of neuromuscular respiratory muscle weakness in 51 of 66 patients and reduced carbon monoxide diffusing capacity in 11 of 35 patients. However, only 6 patients had radiographic evidence of interstitial lung disease (2 anti-HMGCR Ab-positive and 4 seronegative). Overnight oximetry revealed desaturations in 24 of 38 patients. Six patients required mechanical ventilation and 7 required noninvasive ventilatory support.
Most patients with NAM exhibited cardiac and respiratory muscle dysfunction. Immunotherapy can improve echocardiographic abnormalities. Interstitial lung disease was rarely identified. Formal evaluation of cardiac and respiratory status should be integral in assessment of patients with NAM.
描述坏死性自身免疫性肌病（NAM）患者的心肺异常。
回顾性分析 2004 年 1 月 1 日至 2018 年 9 月 20 日在我院神经肌肉科就诊的 NAM 患者的心肺特征，评估其自身抗体状态和心脏病史。比较患者亚组的临床特征和实验室检查结果。
共纳入 109 例 NAM 患者：36 例抗 3-羟基-3-甲基戊二酰辅酶 A 还原酶抗体（抗-HMGCR Ab）阳性，18 例抗信号识别颗粒抗体（抗-SRP Ab）阳性（3 例同时抗-HMGCR/抗-SRP Ab 阳性），58 例血清学阴性。诊断时的中位年龄为 60 岁（范围 18-86 岁）。43 例患者有呼吸困难，32 例患者有心脏疾病风险（10 例冠心病，28 例高血压）。86 例患者中 55 例心电图异常（33 例无心脏危险因素），包括 QT 间期延长（31 例）、传导阻滞（19 例）和房性或室性期前收缩（10 例）。72 例患者中有 34 例行超声心动图检查，其中 45 例无心脏疾病风险的患者中有 19 例异常。超声心动图异常包括左心室舒张功能障碍（31 例）和收缩功能障碍（8 例）。11 例治疗后左心室舒张功能障碍改善 4 例。肺功能检查显示 66 例中有 51 例提示神经肌肉呼吸肌无力，35 例中有 11 例一氧化碳弥散量降低。然而，仅 6 例患者有间质性肺病的放射学证据（2 例抗-HMGCR Ab 阳性，4 例血清学阴性）。夜间血氧饱和度检查发现 38 例中有 24 例存在血氧饱和度下降。6 例患者需要机械通气，7 例需要无创通气支持。
大多数 NAM 患者存在心脏和呼吸肌功能障碍。免疫治疗可改善超声心动图异常。间质性肺病很少见。在评估 NAM 患者时，应将心脏和呼吸状态的全面评估纳入其中。
