Coletta C, Carboni P, Carunchio A, Porro G, Bacci V
Servizio di Cardiologia, Ospedale S. Spirito, Rome, Italy.
Int J Cardiol. 1989 Sep;24(3):283-8. doi: 10.1016/0167-5273(89)90005-3.
Tremors of the isoelectric line in routine electrocardiograms have been described in patients with spinal muscular atrophy and have been interpreted as fasciculations of denervated muscles. In order to evaluate this phenomenon, 13 patients with spinal muscular atrophy have been studied (average age: 37.3 months). A first electrocardiogram was recorded routinely; a second tracing was then recorded with double sensitivity and double speed. In addition, all patients were evaluated clinically and had M-mode and cross-sectional echocardiography. Regular and constant spikes on the isoelectric electrocardiographic line were recorded in 12 patients (93.4%); their frequency ranged from 39 to 48 cycles/sec (average: 42.08 +/- 2.64). Contrary to previous reports, we found an "abnormal" electrocardiogram in all our patients with severe spinal muscular atrophy. The only patient with a normal electrocardiogram had a mild and clinically stable form of spinal muscular atrophy. We did not find any significant structural cardiac abnormality by clinical and echocardiographic evaluation. We conclude that continuous tremor on the isoelectric line of electrocardiogram represents a characteristic of spinal muscular atrophy in these patients. It is a result of muscle fasciculations and does not imply any abnormality of the heart.
脊髓性肌萎缩症患者常规心电图等电位线的震颤已被描述，并被解释为失神经肌肉的肌束颤动。为了评估这一现象，对13例脊髓性肌萎缩症患者进行了研究（平均年龄：37.3个月）。首先常规记录一份心电图；然后以双倍灵敏度和双倍速度记录第二份描记图。此外，所有患者均接受了临床评估，并进行了M型和横断面超声心动图检查。12例患者（93.4%）在心电图等电位线上记录到规则且持续的尖峰；其频率范围为39至48次/秒（平均：42.08±2.64）。与先前的报告相反，我们发现所有严重脊髓性肌萎缩症患者的心电图均“异常”。唯一心电图正常的患者患有轻度且临床稳定型的脊髓性肌萎缩症。通过临床和超声心动图评估，我们未发现任何明显的心脏结构异常。我们得出结论，心电图等电位线上的持续震颤是这些患者脊髓性肌萎缩症的一个特征。它是肌肉肌束颤动的结果，并不意味着心脏有任何异常。
