This study was performed to determine whether bradycardia complicates the postoperative course of patients undergoing carotid endarterectomy (CEA). The records of 216 patients undergoing 233 CEAs over a 2-year period were reviewed. Patients were divided into two groups based on their lowest Surgical Intensive Care Unit (SICU) heart rate (HR). Those with HR < 60 were in the Bradycardic (BRADY) group and those with HR > or = 60 were in the Non-Bradycardic (NON-BRADY) group. One hundred and sixteen patients developed bradycardia, with a mean (+/- SEM) HR of 51.1 +/- 0.5, compared with 117 NON-BRADY patients with a mean HR of 70.6 +/- 0.9 (P < 0.0005). There were no significant differences between the groups in age, use of cardioactive drugs, SICU severity of illness, or length of SICU stay. The systolic blood pressure for BRADY patients averaged 144 +/- 2.2 on admission and 144 +/- 2.2 (P = NS) in the SICU, while that of NON-BRADY patients rose from 143 +/- 2.3 on admission to 156 +/- 2.5 (P = 0.001). Fifty-four patients receiving a second CEA had a SICU HR not significantly different from those patients undergoing a first CEA. Of 17 patients who underwent bilateral CEAs during the study period, SICU HRs averaged 65.1 +/- 3.7 after the first procedure and 64.7 +/- 3.6 after the second (P = NS). The authors conclude that bradycardia following CEA is a frequent but benign postoperative finding that does not affect outcome, cause significant hypotension, or prolong the SICU stay.