Sinus bradycardia and asystole during spinal and epidural anesthesia: a report of 13 cases.

Study Objective: To characterize the clinical features that predispose to sinus bradycardia and cardiac arrest during spinal and epidural anesthesia.

Design: Retrospective clinical review.

Setting: University affiliated medical center.

Patients: 13 patients, aged 26 to 76 years, who suffered severe sinus bradycardia or asystole over a 5-year period, during which approximately 4,000 regional anesthetics were administered.

Measurements And Main Results: Case histories of 13 patients who developed severe sinus bradycardia or asystole during spinal or epidural anesthesia are summarized. Twelve cases occurred during spinal anesthesia, and the thirteenth, during epidural anesthesia. In all but one case, the acute event occurred 15 minutes or longer from the time of the anesthetic injection. Resuscitation was successful in all cases, with no postoperative sequelae.

Conclusion: The clinical picture suggests a reflex cause, possibly associated with low right-sided cardiac filling pressure. No common precipitating cause or high-risk patient profile was noted.