Osmosis video - ECG normal sinus rhythm

Normal sinus rhythm is when the heart's electrical activity is regular and originates in the heart's natural pacemaker, the sinoatrial (SA) node. The (SA) node is located in the right atrium and regularly fires electrical impulses. On an ECG, the normal sinus rhythm is characterized by a P wave corresponding to atrial depolarization wave, and it is followed by an isoelectric line where the depolarization wave goes through the atrioventricular (AV) node. After, there is the QRS complex that represents ventricular depolarization. After QRS follows an isoelectric pause called ST segment, precedes ventricular repolarization represented by T wave.