Understanding Cardiac Arrest & What Causes It

Understanding Sudden Cardiac Arrest — What Causes It?

Sudden Cardiac Arrest (SCA) occurs when the heart experiences an abrupt and unexpected disturbance in its electrical system, causing it to stop beating effectively. This life-threatening condition is driven by an abnormal heart rhythm known as ventricular fibrillation, where the heart beats chaotically and is unable to pump blood to the brain and body.

The most common underlying cause is coronary heart disease , A condition where plaque builds up inside the coronary arteries, Restricting the supply of blood to the heart. Between a third and a half of people who experience a heart attack may go on to suffer sudden cardiac death, As heart attacks can also cause scarring of the heart muscle, leading to further dangerous rhythm problems.

Beyond coronary disease, additional significant risk factors include high blood pressure, high cholesterol, smoking, obesity, diabetes, a lack of physical exercise, excessive alcohol use, and a family history of heart conditions.

Structural heart defects account for approximately 10–15% of cases, While inherited conditions such as cardiomyopathy, A disease of the heart muscle can also disrupt the heart's electrical signals and increase the risk of SCA.

Critically, Research shows that around 25% of adults who suffer a cardiac arrest had no symptoms whatsoever before it occurred, Which is why awareness, Early access to defibrillators, and knowledge of CPR are so vital.

Tragically out-of-hospital cardiac arrests carry a fatality rate of nearly 90% , But that figure can change dramatically when bystanders are equipped and ready to act.