Carotid palpation at two exercise intensities

Abstract
It remains unclear whether carotid palpation (CP) should be used to count post-exercise heart rate (HR). We hypothesized that the carotid sinus, when stretched or compressed by external pressure, results in an increased nerve activity to the cardiovascular areas in the brain stem, with a resultant increase in parasympathetic activity and a decrease in sympathetic activity. The primary purpose of this study was to investigate the effects of CP and no CP on postexercise HR determination at two exercise intensities. The secondary purposes were to investigate whether CP during exercise would elicit a decrease in HR and the effects of CP on post-exercise blood pressure. Twenty-one healthy females served as subjects. During the final min of each exercise intensity, two 10-s HRs were recorded by continuous ECG (i.e., 10 s without palpation and 10 s with palpation). Immediately post-exercise at each intensity, the carotid artery was either palpated (Phase I) or not palpated (Phase II). At 60 and 80% intensity, with 10-s CP, post-exercise HR decreased 12.4 and 7 beats-min-1, respectively (both were significant; P1 in 10-s, respectively (both were significant; P<0.05). CP during exercise did not elicit a carotid sinus reflex, and post-exercise CP did not alter blood pressure readings. These findings were generally contrary to previous research on CP and were determined to be important in that the correct technique was used by the investigators. It is concluded there is sufficient concern to suggest that CP should not be used to determine post-exercise HR.