Final answer:
Ablation is performed during sinus rhythm to correct cardiac arrhythmias and restore the heart's normal rhythmical beating, which is controlled by the pacemaker cells of the sinoatrial node. When these arrhythmias are chronic, cardiologists may implant an artificial pacemaker or use a defibrillator to stimulate sinus rhythm.
Step-by-step explanation:
Ablation is performed during sinus rhythm to treat cardiac arrhythmias, where the heart beats irregularly, either too fast or too slow. The procedure involves modifying the tissue in the heart that causes the abnormal rhythm. The goal of ablation is to restore the heart's normal rhythm, known as sinus rhythm, which is the normal, rhythmical beating of the heart established by the sinoatrial (SA) node.
When arrhythmias become chronic, the heart may maintain a junctional rhythm, originating in the AV node, which can be slower than a normal sinus rhythm. In such cases, a cardiologist may use ablation or implant an artificial pacemaker to deliver electrical impulses to the heart muscle to ensure it continues to contract and pump blood effectively. These devices, which can also include built-in defibrillators, are programmable to provide stimulation either upon demand or continuously.
Defibrillators, such as external automated defibrillators (EADs), can also be used to stop the heart briefly so that the SA node can trigger a normal conduction cycle and restore sinus rhythm. EADs are now widely available in public places and are equipped with simple verbal instructions to allow nonmedical personnel to possibly save a life.