749-1 Redefining Normal Sinus Heart Rate

Abstract

When and how the traditional limits of the normal heart rate range (NHR), 60–100 bpm, were selected is unclear. The purpose of this study is to redefine the NHR and the definitions for sinus bradycardia and tachycardia. We investigated the data of 536 consecutive, fully healthy, non cardiac subjects (447 males, 89 females, aged 22–81 yrs) who attended a health screening program and treadmill exercise testing. The lowest resting heart rate was recorded during ECG records, holter monitoring, baseline exercise data and physical examination. The mean (± SD) resting heart rate for males is 64.1 ± 10.1, for females it is 69.5 ± 10.1 (p < 0.004). and for total group it is 65.0 ± 10.3 bpm. Mean heart rate by quinquennium is within the narrow range of 65–73 bpm. The mean heart rate, depending on age group, is 63–65 bpm for males and 65–73 bpm for females. Linear regression of HR against age in total group yields: HR = 68.6–(0.074 x age), r = -0.067, and mean ± 95% confidence interval: 65.0 ± 20.2 (44.8,85.2). standard error = 10.3; In males, HR = 67.7–(0.074 × age). r = -0.067, mean ± 95% confidence interval: 64.1 ± 19.8 144.3,83.9). standard error = 10.1; In females, HR = 73.3–(0.079 × age). r = -0.076, and mean ± 95% confidence interval: 69.5 ± 20.0 (49.5,89.5). and standard error = 10.1. There is no statistically significant relationship of HR and age. Normal sinus heart rate range should be defined for males between 44 and 84 bpm and between 50 and 90 bpm for females. In clinical practice, these thresholds should be < 45 and > 85 bpm for males as well as < 50 and > 90 bpm for females to improve the sensitivity of sinus tachycardia and specificity of sinus bradycardia identification.