Groh William J, Groh Miriam R, Saha Chandan, Kincaid John C, Simmons Zachary, Ciafaloni Emma, Pourmand Rahman, Otten Richard F, Bhakta Deepak, Nair Girish V, Marashdeh Mohammad M, Zipes Douglas P, Pascuzzi Robert M
Department of Medicine, Krannert Institute of Cardiology, Indiana University, Indianapolis 46202, USA.
N Engl J Med. 2008 Jun 19;358(25):2688-97. doi: 10.1056/NEJMoa062800.
Sudden death can occur as a consequence of cardiac-conduction abnormalities in the neuromuscular disease myotonic dystrophy type 1. The determinants of the risk of sudden death remain imprecise.
We assessed whether the electrocardiogram (ECG) was useful in predicting sudden death in 406 adult patients with genetically confirmed myotonic dystrophy type 1. A patient was characterized as having a severe abnormality if the ECG had at least one of the following features: rhythm other than sinus, PR interval of 240 msec or more, QRS duration of 120 msec or more, or second-degree or third-degree atrioventricular block.
Patients with severe abnormalities according to the entry ECG were older than patients without severe abnormalities, had more severe skeletal-muscle impairment, and were more likely to have heart failure, left ventricular systolic dysfunction, or atrial tachyarrhythmia. Such patients were more likely to receive a pacemaker or an implantable cardioverter-defibrillator during the follow-up period. During a mean follow-up period of 5.7 years, 81 patients died; there were 27 sudden deaths, 32 deaths from progressive neuromuscular respiratory failure, 5 nonsudden deaths from cardiac causes, and 17 deaths from other causes. Among the 17 patients who died suddenly in whom postcollapse rhythm was evaluated, a ventricular tachyarrhythmia was observed in 9. A severe ECG abnormality (relative risk, 3.30; 95% confidence interval [CI], 1.24 to 8.78) and a clinical diagnosis of atrial tachyarrhythmia (relative risk, 5.18; 95% CI, 2.28 to 11.77) were independent risk factors for sudden death.
Patients with adult myotonic dystrophy type 1 are at high risk for arrhythmias and sudden death. A severe abnormality on the ECG and a diagnosis of an atrial tachyarrhythmia predict sudden death. (ClinicalTrials.gov number, NCT00622453.)
1型强直性肌营养不良这一神经肌肉疾病可因心脏传导异常而导致猝死。猝死风险的决定因素仍不明确。
我们评估了心电图（ECG）对406例经基因确诊的成年1型强直性肌营养不良患者猝死的预测价值。若心电图具有以下至少一项特征，则将患者判定为存在严重异常：非窦性心律、PR间期240毫秒或更长、QRS时限120毫秒或更长、二度或三度房室传导阻滞。
根据初始心电图判定为严重异常的患者比无严重异常的患者年龄更大，骨骼肌损伤更严重，更有可能出现心力衰竭、左心室收缩功能障碍或房性快速性心律失常。此类患者在随访期间更有可能接受起搏器或植入式心律转复除颤器治疗。在平均5.7年的随访期内，81例患者死亡；其中27例为猝死，32例死于进行性神经肌肉呼吸衰竭，5例死于非猝死性心脏原因，17例死于其他原因。在17例猝死且评估了心脏停搏后心律的患者中，9例观察到室性快速性心律失常。严重心电图异常（相对危险度，3.30；95%可信区间[CI]，1.24至8.78）和房性快速性心律失常的临床诊断（相对危险度，5.18；95%CI，2.28至11.77）是猝死的独立危险因素。
成年1型强直性肌营养不良患者发生心律失常和猝死的风险很高。心电图严重异常和房性快速性心律失常的诊断可预测猝死。（临床试验注册号，NCT00622453。）
