what occurs during the p_r interval of a normal ecg
This represents the time that it takes for the electrical impulse generated in the sinus node to travel through the atria and across the atrioventricular node to the ventricles. The normal PR interval is 0.12 to 0.20 seconds, or 120 to 200 milliseconds. Multiple abnormalities of the PR interval â including prolongation of the PR interval, shortening of the PR interval and variation from beat to beat â can occur; these are discussed in detail in ECG Reviews and Criteria.