Cardioversion

A very fast or irregular heartbeat is called arrhythmia. Arrhythmias can lead to fainting, heart attack, stroke, or sudden cardiac death.

Cardioversion uses high-energy shock to reset the heart to a regular rhythm. It is different from chemical cardioversion where medications are used to try to reset to a normal rhythm.

A normal heartbeat is triggered by an electrical signal from a special group of cells in the sinoatrial (SA) node located in the right atrium (upper right chamber of the heart). The signal then travels down to the ventricles, causing the heart to contract from top to bottom. The order in which the heart contracts is important to the exchange of unoxygenated blood entering the heart and the oxygenated blood exiting the heart.

Several problems can arise to disrupt the electrical impulses and lead to an abnormal heart rhythm (arrhythmia). When the disruptions become life-threatening (and possibly lead to sudden death), cardioversion is suggested. Cardioversion is typically a scheduled procedure but can also be an emergent event for very severe symptoms.

Cardioversion is not the same as defibrillation, as defibrillation is used to stop very severe arrhythmias with a stronger shock. Electrical cardioversion is used for several types of abnormal heart rhythms, most commonly atrial fibrillation (AFib). AFib causes the heart to quiver instead of beat. It increases the risk of stroke and causes fatigue, shortness of breath, and a very fast heartbeat.