Sudden Cardiac Death
Overview
Plain-Language Overview
Sudden Cardiac Death is a condition where the heart unexpectedly stops beating, leading to a sudden loss of blood flow to the body. It primarily affects the heart, which is part of the cardiovascular system. This abrupt event can cause a person to collapse and lose consciousness within minutes. The main health impact is the immediate risk of death if not treated quickly. It often results from abnormal heart rhythms called arrhythmias. Common causes include heart attacks or inherited heart conditions. Recognizing the signs and understanding the seriousness of this condition is crucial.
Clinical Definition
Sudden Cardiac Death (SCD) is defined as an unexpected death due to cardiac causes occurring within a short time period, usually within one hour of symptom onset. The core pathology involves a fatal ventricular arrhythmia, most commonly ventricular fibrillation or ventricular tachycardia, leading to cessation of effective cardiac output. The usual underlying causes include ischemic heart disease, cardiomyopathies, and inherited channelopathies such as long QT syndrome or Brugada syndrome. SCD is a major cause of mortality worldwide and often occurs in individuals with known or occult structural heart disease. It is distinguished from other causes of sudden death by the presence of a primary cardiac electrical or mechanical failure. Early recognition and intervention are critical to prevent death.