What does sudden cardiac arrest (SCA) signify?

Sudden cardiac arrest (SCA) is defined as a sudden and unexpected loss of heart function, breathing, and consciousness, primarily caused by an electrical disturbance in the heart. This electrical malfunction can lead to arrhythmias, particularly ventricular fibrillation, where the heart cannot effectively pump blood, resulting in a cessation of blood flow to vital organs.

While options like a sudden heart attack and a blockage in a coronary artery might seem related, they are distinct from SCA. A heart attack, also known as a myocardial infarction, occurs due to obstruction of blood flow to the heart muscle, typically caused by a blockage in a coronary artery, leading to damage of the heart tissue. Gradual loss of heart function refers to chronic heart conditions leading up to heart failure rather than an immediate and sudden event like SCA. Thus, the characterization of SCA as an electrical issue accurately captures why the heart stops functioning suddenly, making it the correct choice.