| Abstract: | ![]()
The influence of different heart rates and rhythm on reaction time performance was examined in two groups of experimental subjects, heart rate in one group being varied by atrial pacing and in the other group by ventricular pacing. A mixed preparatory interval series of visual reaction time trials was employed, with preparatory interval durations of 3, 4, and 5 sec. Study 1 subjects, exposed to atrial pacing in a cardiac catheterization laboratory immediately before coronary artery cineangiography, demonstrated no change in reaction time response with the pacing situation when heart rate was 115 beats per minute (bpm). Response speed was most rapid with the 5 sec preparatory interval, slowest with the exposure to an exogenously-induced tachycardia. Presentation first of a variable paced tachycardia following a regular tachycardia was associated with slightly prolonged times in both situations, as compared to reaction time produced with the reverse order of pacing presentation. These differences were not statistically significant. Presence or absence of cineangiographic evidence or coronary arteriosclerosis within Study 1 exerted no effect on reaction time performance. Study 2 individuals, paced with an external (Chardack) pacemaker in a quiet laboratory environment, confirmed the results obtained from Study 1. These data would suggest that the level of background heart rate is unimportant as a determinant of reaction time response. |
