Engel T R
Geriatrics. 1981 Apr;36(4):65-72.
SSS is characterized by sinus bradycardia and asystole. Syncope from SSS carries a better prognosis than syncope from heart block. AV node heart block is signaled by P-R prolongation and Wenckebach periodicity. Symptoms vary in severity, with or without syncope. TF heart block is preceded by left-bundle branch block or by right-bundle branch block plus fascicular block. Prognosis for the unpaced patient subject to TF block is grave. The fact that ECGs suggesting sinus bradycardia, P-R prolongation, and bifascicular block (all causes of syncope) are very common among the elderly and usually have an innocent course, increases the difficulty of deciding which patient will benefit from pacing. Certainly a pacemaker should not be inserted because of abnormal ECG alone.
病态窦房结综合征的特征为窦性心动过缓和心搏停止。病态窦房结综合征导致的晕厥比心脏传导阻滞导致的晕厥预后更好。房室结传导阻滞表现为P-R间期延长和文氏周期。症状严重程度各异，可伴有或不伴有晕厥。三分支传导阻滞之前常有左束支传导阻滞或右束支传导阻滞加分支阻滞。未接受起搏治疗的三分支传导阻滞患者预后严重。提示窦性心动过缓、P-R间期延长和双分支传导阻滞（均为晕厥原因）的心电图在老年人中非常常见，且通常为良性过程，这增加了判断哪些患者将从起搏治疗中获益的难度。当然，绝不应仅因心电图异常就植入起搏器。
