Question

correlate the sequence of heart excitation with the electrocardiogram

Answer 1

The important points of ECG (Electrocardiogram) are P wave, QRS complex and T wave. P wave shows depolarization of the atria, atria contracts after the start of P wave. QRS complex shows the depolarization of the ventricles. The ventricles start to contract when the QRS reaches the peak of the R wave. T wave shows the repolarization of the ventricles. Whereas the repolarization of the atria occurs during the QRS complex. PR interval shows the duration from the beginning of atrial depolarization i.e P wave to the initiation of the QRS complex. ST Segment shows the interval between ventricular depolarization and repolarization. QT interval shows the time from the beginning of the QRS complex i.e ventricular depolarization till the end of the T wave i.e ventricular repolarization.