How to read an ECG
Introduction Conduction through the heart is dependent on pacemaker cells, which are organised into key structures. The heart is a dual pump that sits at the centre of the cardiovascular system. It is composed of both contractile cells and autorhythmic cells (also known as pacemaker cells). Approximately 1% of cardiac tissue is composed pacemaker cells, which are organised into key structures and can undergo spontaneous depolarisation. Depolarisation refers to the electrical changes that occur within a muscle to allow it to contract. The heart is essentially one big muscle that can contract by itself. We can detect these electrical changes,