What are the key distinctions between cardiac arrest and a heart attack?

Cardiac arrest and heart attack are two serious heart-related emergencies that are often confused, but they have distinct causes, symptoms, and treatments. Understanding the difference between these two conditions can make a significant difference in providing the right response in an emergency.

What is Cardiac Arrest?

Cardiac arrest is a sudden loss of heart function caused by a malfunction in the heart’s electrical system, stopping blood circulation and breathing. Without immediate treatment, it can cause brain damage, organ failure, and death. Performing CPR is critical, as it maintains blood flow to vital organs until professional medical help arrives.
Symptoms of Cardiac Arrest:
• Sudden collapse
• No pulse
• Absence of breathing
• Loss of consciousness
It strikes suddenly and without warning, making it imperative to act fast. Emergency CPR and defibrillation are the only treatments that can restore the heart’s normal rhythm and potentially save a life.

What is a Heart Attack?

A heart attack, or myocardial infarction, happens when blood flow to a section of the heart muscle is obstructed, usually by a clot in a coronary artery. This blockage deprives the heart of oxygen, leading to tissue damage. Unlike cardiac arrest, a heart attack is a circulatory issue and often presents warning signs, allowing for timely medical intervention.
Symptoms of a Heart Attack:
• Chest pain or discomfort (often radiating to the arm, neck, or jaw)
• Shortness of breath
• Nausea or vomiting
• Excessive sweating
• Fatigue
Heart attack symptoms can develop gradually or suddenly, and while chest pain is the most recognized symptom, it isn’t always present. Some people, especially women, may experience more subtle symptoms like shortness of breath, nausea, or fatigue.

Key Differences Between Cardiac Arrest and Heart Attack

Though both conditions are serious and involve the heart, they differ in several key ways:
1. Cause:
Cardiac arrest results from an electrical malfunction in the heart, whereas a heart attack occurs due to a blockage in the blood vessels that supply oxygen to the heart muscle.
2. Onset:
Cardiac arrest occurs suddenly and without warning. In contrast, heart attacks often present warning signs, such as chest pain or discomfort, that may build over time.
3. Treatment:
Cardiac arrest requires immediate CPR and defibrillation to restore the heart’s normal rhythm. A heart attack requires urgent medical attention to restore blood flow, typically through medications or surgical procedures like angioplasty.
Responding to Cardiac Arrest and Heart Attack
Cardiac Arrest Response: If you witness someone collapsing, showing no signs of breathing or pulse, it is likely cardiac arrest. Immediate action is crucial:
• Call emergency services.
• Begin CPR immediately by pushing hard and fast in the center of the chest.
• Use an automated external defibrillator (AED) if available.

Every second counts during cardiac arrest. Immediate CPR can double or even triple the chances of survival until medical help arrives.

Heart Attack Response:

If someone shows symptoms of a heart attack, such as chest pain, shortness of breath, or discomfort in the arm, neck, or jaw:
• Call emergency services immediately.
• Help the person sit down and stay calm.
• If available, have them chew aspirin (if not allergic) to help reduce blood clotting.
• Stay with them until help arrives.

Conclusion

While both cardiac arrest and heart attacks are life-threatening, understanding their differences can guide you in responding appropriately during an emergency. Cardiac arrest requires immediate CPR and defibrillation, while a heart attack demands urgent medical attention to restore blood flow to the heart. Recognizing the signs and acting swiftly can save lives in both cases.

Dr. Kumar Kenchappa, Consultant – Interventional Cardiologist, Manipal Hospital Hebbal