Written By: Longjam Dineshwori | Updated : November 6, 2020 10:36 AM IST
Heart attack is a common cause of sudden cardiac arrest, but most heart attacks do not lead to cardiac arrest.
The terms heart attack and sudden cardiac arrest are often used interchangeably, but they are not synonyms. A heart attack is a circulation problem and it occurs when blood flow to the heart is blocked due to a sudden blockage in a coronary artery. In contrast, sudden cardiac arrest is an electrical problem which happens when the electrical signals that control the heart's pumping ability malfunctions, causing it to beat rapidly and chaotically or to stop beating altogether unexpectedly.
Heart attacks also called myocardial infarctions can result from a plaque build-up in the arteries (atherosclerosis), blood clots, a torn blood vessel, or a blood vessel spasm (less common though). Also called coronary artery disease, atherosclerosis causes most heart attacks. The build-up of fats, cholesterol and other substances called plague in and on your artery walls can narrow the arteries and restrict blood flow. When this plaque burst, it can lead to the formation of blood clots that can prevent blood from getting to the heart muscle.
Most sudden cardiac deaths are caused by arrhythmias (abnormal heart rhythms), ventricular fibrillation being the most common one. Ventricular fibrillation is when the ventricles (the heart's lower chambers) quiver instead of pumping normally. Death will occur within minutes, if left untreated.
Sudden cardiac death occurs most commonly in adults in their mid-30s to mid-40s, affecting men more than women. In contrast, men age 45 or older and women age 55 or older are at higher risk of having a heart attack than are younger men and women. But some studies indicate that heart attack is becoming more common in younger people, especially women.
Usually, symptoms of heart attack begin hours, days or weeks before the actual event. Below are some warning symptoms that could signal a heart attack:
Unlike the heart attack, sudden cardiac arrest occurs suddenly and often without warning. Within a few minutes, a person may lose consciousness as blood flow to the brain reduces drastically. The victim may die within minutes if not given treatment. Some people may experience a racing heartbeat or dizziness before a sudden cardiac arrest. But over half of the cases of sudden cardiac arrest occurs without prior symptoms.
If you suffer from heart attack, you're also at risk of having sudden cardiac arrest. Often, sudden cardiac arrest follows a heart attack, or occurs during recovery. Having said so, most heart attacks do not lead to cardiac arrest.
Other heart conditions that can lead to sudden cardiac arrest include a thickened heart muscle (cardiomyopathy), heart failure, arrhythmias, particularly ventricular fibrillation, a clot in the lungs, a serious imbalance of potassium, magnesium, or other minerals in the blood, a drug overdose, or a blow to the chest.
If you or someone near you is experiences symptoms of a heart attack or cardiac arrest, call emergency medical services right away or seek immediate medical attention. If the victim becomes unconscious and stops breathing, give him/her hands-only cardiopulmonary resuscitation (CPR) until help arrives. This will keep the blood circulating to the brain and heart until a defibrillator or emergency team arrives to get the heart beating normally. However, CPR is not needed unless the heart attack victim goes into cardiac arrest.
