Reproducibility of heart rate measured in the clinic and with 24-hour intermittent recorders

This study was undertaken to assess the reproducibility of office versus am bulatory heart rates in 839 hypertensive subjects participating in the Hype rtension and,Ambulatory Recording Venetia Study (HARVEST). A 24-hour heart rate was recorded twice; this procedure was repeated three months later. Re producibility was better for ambulatory than for office measurement, and wa s greater for 24-hour than for daytime heart rate, and lowest for night-tim e heart rate. Reproducibilty of office heart rate was impaired above 85 bpm , and was poorer in subjects with more severe office hypertension. A small but significant decrease in average daytime (-1 bpm, P < 0.0001) and virtua lly no change in night-time heart rate (-0.3 bpm, NS) were observed at repe at recording. Heart rate reproducibility indices were related to the extent of the heart rate and blood pressure white-coat effect, but did not vary a ccording to age, gender, body mass index, day-night blood pressure differen ce, or alcohol or tobacco use, Results indicate that heart rate recorded ov er the 24 hours has a better reproducibility than office heart rate, and co uld thus be a better prognostic indicator than traditional measurement of r esting heart rate in the hospital setting. Am J Hypertens 2000; 13:92-98 (C ) 2000 American Journal of Hypertension, Ltd.