Asensio Enrique, Gómez María, Narváez René, Castillo Lilia, Oseguera Jorge, Dorantes Joel, Orea Arturo, Hernández Pablo, Rebollar Verónica
Departamento de Cardiología, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán.
Rev Invest Clin. 2003 May-Jun;55(3):270-5.
Myasthenia gravis (MG) is a disease characterized by the presence of acetylcholine receptor-directed autoantibodies. Functional cardiac disorders are the most common since there is no neuro-muscular plate in the heart. Autonomic nervous system is involved in MG, but the cardiac manifestations of such an involvement remain unclear. Previous EKG studies in patients with MG show heterogeneous results.
A retrospective, descriptive and observational study was performed to know the main electrocardiographic characteristics and some autonomic nervous function in a series of patients with MG.
One-hundred seventeen patients with EKG were analyzed. Twenty-eight were 47.9 +/- 20 years-old males, and 89 were women of 35.2 +/- 7.7 years (p = 0.001). 49 (41.9%) EKG had no changes, while 68 (58.1%) did. The main QT dispersion was 35.5 +/- 18.4 ms among those with some anomaly (p = 0.27). In 54 (78.3%) patients with an abnormal EKG there was T wave alternans, which was also present in 35 (71.4%) (p = 0.32) patients with normal EKG.
MG is frequently associated to unspecific EKG changes. Dynamic electrocardiography allows a precise evaluation of the kind of cardiac involvement derived from MG, specifically the one related to the autonomic function, that is apparently affected in both the sympathetic and parasympathetic arms.
重症肌无力（MG）是一种以存在乙酰胆碱受体定向自身抗体为特征的疾病。功能性心脏疾病最为常见，因为心脏中没有神经肌肉板。自主神经系统参与了重症肌无力，但这种参与的心脏表现仍不清楚。先前对重症肌无力患者的心电图研究结果不一。
进行了一项回顾性、描述性和观察性研究，以了解一系列重症肌无力患者的主要心电图特征和一些自主神经功能。
对117例有心电图检查的患者进行了分析。28例为47.9±20岁的男性，89例为35.2±7.7岁的女性（p = 0.001）。49例（41.9%）心电图无变化，而68例（58.1%）有变化。在有异常的患者中，主要QT离散度为35.5±18.4毫秒（p = 0.27）。在54例（78.3%）心电图异常的患者中有T波交替，在35例（71.4%）心电图正常的患者中也有T波交替（p = 0.32）。
重症肌无力常与非特异性心电图改变相关。动态心电图可精确评估重症肌无力所致的心脏受累类型，特别是与自主神经功能相关的类型，自主神经功能在交感神经和副交感神经方面显然均受到影响。
