ECG r-r is the normal value of R-R. R-R usually refers to the interval between two heartbeats, and its normal value is usually between 0.6-1.0s. R-R in ECG usually stands for heart rate, which ranges from 60-100 beats per minute in a normal person in a quiet and awake state. According to the electrocardiogram recording paper, every 25mm / s, every two horizontal lines between the 1mm that is, 1 small frame represents 0.04s, and the normal heart rate range between 15 small frame to 25 small frame, so the normal value of R-R between 0.6-1.0s. When R-R value <0.6s, suggests bradycardia, common in coronary heart disease, atrioventricular block, etc.; but R-R value >1.0s, suggests tachycardia, common in atrial fibrillation, supraventricular tachycardia and so on. If abnormal heart rate and arrhythmia occur, it is recommended to go to a regular hospital to avoid delay.