Cardiologist doctor near to me Please take care of your heart Sudden Cardiac Arrest- Do u know why It Happens & how it happens You collapse without warning. Your heart stops beating, and blood stops flowing to your brain and other organs. Within seconds, you stop breathing and have no pulse. This is sudden cardiac arrest. *** Causes *** The immediate cause of most sudden cardiac arrests is an abnormal heart rhythm. The heart’s electrical activity becomes chaotic, and it can’t pump blood to the rest of the body. Conditions that can trigger sudden cardiac arrest include Coronary artery disease . This is the most common cause of sudden cardiac arrest in people older than 35. Cardiomyopathy . When you have this condition, your heart muscle becomes enlarged or thick, so it's weakened. Long QT syndrome and Brugada syndrome . These disorders of the heart’s electrical system can cause abnormal heart rhythms. Marfan syndrome . This inherited disorder can cause parts of the heart to stretch and become weak. Heart birth defects. Even if you have had surgery to correct a defect, you are still at risk for sudden cardiac arrest.