Video - ECG intervals

ECG intervals are major elements to look at when reading an ECG strip. These include the PR interval, the QRS complex itself, the QT, and the RR intervals. The PR interval is the time from the beginning of the P wave to the beginning of the QRS complex. It represents the time between the beginning of atrial depolarization and the beginning of ventricular depolarization, which normally lasts about 0.12-0.20 seconds. The QRS complex represents ventricular depolarization and typically lasts less than 100 milliseconds. Next, the QT interval is measured from the beginning of the QRS complex to the end of the T wave. It represents the ventricular systole and typically lasts less than half of the individual's cardiac cycle. Finally, the RR interval is measured from one R wave peak to the next. It helps to calculate the heart rate and tell if it's regular.