Heart Conduction System:What Is It & How It Works

The heart’s conduction system is a complex network of specialized muscle cells that are responsible for initiating and coordinating the electrical impulses that control the rhythm of the heart. Unlike regular heart muscle cells, which contract in response to external stimulation, the cells in the conduction system are unique in that they can generate their own electrical impulses (automaticity). This system ensures the heart beats regularly and that the atria and ventricles contract in a synchronized manner.

The heart conduction system consists of five key components that work together to generate and conduct electrical impulses, coordinating the heart's rhythm. These components are:

• The sinoatrial (SA) node
• The atrioventricular (AV) node
• The bundle of His
• The left and right bundle branches
• The Purkinje fibres

When any part of the conduction system is damaged or malfunctioning, it can lead to arrhythmias, or abnormal heart rhythms. For instance, if the SA node becomes dysfunctional, an ectopic pacemaker (a pacemaker cell outside of the SA node) may take over, leading to an abnormal rhythm. If the AV node is impaired, it can result in heart block, where the electrical impulse is delayed or blocked, preventing the atria and ventricles from coordinating their contractions properly. In more severe cases, damage to the Purkinje fibers or bundle branches can result in a condition known as bundle branch block, where one ventricle may contract later than the other, potentially disrupting normal heart function.

Understanding the heart’s conduction system is crucial for diagnosing and treating various cardiac disorders, including arrhythmias, heart block, and conduction delays. Medical interventions such as pacemakers, defibrillators, and medications are often used to manage these conditions, restoring normal electrical conduction and heart function.