What is the purpose of defibrillation?

Defibrillation serves the critical purpose of delivering a controlled electric shock to the heart, with the primary aim of restoring a normal rhythm in cases of serious arrhythmias, particularly ventricular fibrillation or pulseless ventricular tachycardia. By delivering this shock, defibrillation essentially depolarizes the entire myocardium simultaneously. This action disrupts the chaotic electrical activity of the heart, allowing the natural pacemaker—typically the sinoatrial (SA) node—to resume control over the heart's electrical conduction pathway. Therefore, this coordinated contraction of heart cells facilitates the restoration of effective heartbeat and contributes to re-establishing proper circulation.

The other options present actions that do not accurately describe the objective of defibrillation. While increasing heart rate and stabilizing blood pressure may be secondary outcomes after successful defibrillation or in different contexts of cardiac care, these are not the primary purposes of the procedure. Stimulating atrial contraction is also not linked to the primary function of defibrillation, as the focus is on restoring the overall rhythm rather than localizing activity to the atria alone.