How to Identify Cardiac Arrest: Signs & Symptoms

Did you know that over 35,000 Canadians suffer from cardiac arrest each year? According to the Canadian Red Cross, around 70% of these cardiac arrests happen at home. Surviving sudden cardiac arrest is nearly impossible unless someone performs CPR or uses an automated external defibrillator (AED) combined with CPR.

How can I tell if someone is experiencing cardiac arrest, though? There are many signs which will help you recognize cardiac arrest. 

Recognizing Sudden Cardiac Arrest

Sudden cardiac arrest (SCA) is a different type of heart malfunction from a heart attack, and knowing the differences can help you save someone’s life if they suddenly suffer from this fatal condition.

With a heart attack, the heart may continue beating, but the blood supply to it is compromised. In the event of sudden cardiac arrest, the heart suffers an electrical malfunction that causes it to completely stop beating. This abrupt stopping in the heart function leads to a loss in consciousness, breathing, and blood circulation. Immediate response is required to prevent structural damage to the organs, which quickly leads to death.

Difference Between Cardiac Arrest and Heart Attack

When someone experiences cardiac arrest, it’s crucial to recognize the difference from a heart attack, as both conditions can lead to sudden death if not treated promptly. Cardiac arrest occurs when the heart’s electrical system fails, like a heart failure, leading to a condition such as ventricular fibrillation, which stops the heart muscle from pumping blood effectively. This results in a lack of oxygen-rich blood flowing to vital organs, which can cause brain damage or sudden cardiac death within minutes. Common cardiac arrest symptoms include chest pain, dizziness, and shortness of breath. When cardiac arrest occurs, the person may lose consciousness rapidly. Knowing how to perform cardiopulmonary resuscitation (CPR) and use an automated external defibrillator (AED) can significantly increase survival chances, especially when initiated immediately following the onset of symptoms. Additionally, calling emergency medical services as soon as possible is crucial for improving outcomes.

While both cardiac arrest and a heart attack are critical medical emergencies, they differ fundamentally in their causes and symptoms. A myocardial infarction, or heart attack, occurs when blood flow to a part of the heart, generally coronary arteries, is blocked, often due to a clot in a coronary artery, altering the heart’s rhythm. This blockage deprives the heart muscle of oxygen-rich blood, causing damage or death to the tissue. Unlike cardiac arrest, where the heart stops beating entirely, a person having a heart attack may still have a pulse and can remain conscious, though they might experience severe chest pain, discomfort, or other signs like shortness of breath. Understanding these differences is vital, as the treatment protocols vary significantly: while cardiopulmonary resuscitation and an AED are essential for cardiac arrest, a heart attack requires immediate treatment and may involve medications or surgical interventions to restore blood flow.

Warning Signs of Sudden Cardiac Arrest

Typically, sudden cardiac arrests are unexpected. However, in recent studies of survivors of sudden cardiac arrest (SCA), some common warning signs have been identified. Additionally, most incidents (but not all) precede, or are a result of pre-existing conditions of the heart like coronary, congenital, or valvular heart disease, cardiomyopathy, or cardiomyopathy (enlarged heart).

Risk Factors

• Family history of coronary artery disease
• High blood pressure
• High blood cholesterol
• Smoking
• Diabetes
• Obesity
• Sedentary lifestyle
• Previous heart condition
• Ageing
• Use of illegal substances like amphetamines and cocaine
• Sleep apnea
• Chronic kidney disease
• Males are more at risk than females

• Drug overdose