Sgarbossa E B, Pinski S L, Jaeger F J, Trohman R G, Maloney J D
Dept. of Cardiology, Cleveland Clinic Foundation, OH 44195.
Pacing Clin Electrophysiol. 1992 Nov;15(11 Pt 2):2055-60. doi: 10.1111/j.1540-8159.1992.tb03021.x.
In spite of a normal pacemaker function, syncope still occurs in some patients with sick sinus syndrome (SSS). Causes often remain unknown. To identify predictors and etiologies of this bothersome symptom, we studied 507 patients who received atrial, ventricular, and dual-chamber pacemakers for SSS. During a mean follow-up of 62 +/- 38 months, actuarial incidence of syncope was 3% at 1 year, 8% at 5 years, and 13% at 10 years. Causes were vasovagal (18%), orthostatic hypotension (25.5%), rapid atrial tachyarrhythmias (11.5%), ventricular tachycardia (5%), acute myocardial ischemia (2.5%), and pacemaker/lead malfunction (6.5%). In 13 patients (29.5%), syncope remained unexplained. The only preimplant predictor for syncope was syncope as primary indication for pacemaker implant. Electrocardiographic correlation with bradycardia was not a predictor of relief of syncope during the follow-up.
(1) syncope in paced patients with SSS has multiple etiologies and may be multifactorial; (2) the only predictor of syncope after pacemaker implant is the occurrence of preimplant syncope as the main indication for pacing; (3) extensive Holter monitoring is not useful to document bradycardiac origin of syncope nor to predict its recurrence; (4) SSS probably overlaps with other entities such as autonomic dysfunction, vasovagal syncope, carotid sinus hypersensitivity, and venous pooling, which would provide an explanation for recurrent syncope in patients with normal pacemaker function.
尽管起搏器功能正常，但仍有一些病态窦房结综合征（SSS）患者会发生晕厥。病因通常不明。为了确定这一令人困扰症状的预测因素和病因，我们研究了507例因SSS接受心房、心室和双腔起搏器治疗的患者。在平均62±38个月的随访期间，晕厥的精算发病率在1年时为3%，5年时为8%，10年时为13%。病因包括血管迷走性（18%）、体位性低血压（25.5%）、快速房性心律失常（11.5%）、室性心动过速（5%）、急性心肌缺血（2.5%）以及起搏器/导线故障（6.5%）。13例患者（29.5%）的晕厥原因仍无法解释。植入前唯一的晕厥预测因素是晕厥作为起搏器植入的主要指征。心电图与心动过缓的相关性并非随访期间晕厥缓解的预测因素。
（1）SSS起搏患者的晕厥有多种病因，可能是多因素的；（2）起搏器植入后晕厥的唯一预测因素是植入前晕厥的发生作为起搏的主要指征；（3）广泛的动态心电图监测对于记录晕厥的心动过缓起源或预测其复发并无帮助；（4）SSS可能与自主神经功能障碍、血管迷走性晕厥、颈动脉窦过敏和静脉淤血等其他病症重叠，这可以解释起搏器功能正常患者的反复晕厥。
