heart rate variability normal range
The normal resting adult human heart rate ranges from 60â100 bpm. Tachycardia is a fast heart rate, defined as above 100 bpm at rest. Bradycardia is a slow heart rate, defined as below 60 bpm at rest. During sleep a slow heartbeat with rates around 40â50 BPM is common and is considered normal.ue to individuals having a constant blood volume, one of the physiological ways to deliver more oxygen to an organ is to increase heart rate to permit blood to pass by the organ more often. Normal resting heart rates range from 60â100 bpm. Bradycardia is defined as a resting heart rate below 60 bpm.