Your Heart: The Differences Between Sudden Cardiac Arrest and a Heart Attack

Eating healthy, regularly exercising, and generally looking after the body are the best ways to reduce your chances of suffering a heart attack or an SCA.

• By Adam Maidment
• Oct 01, 2016

The heart is one of the most important organs in the body, however, not many people are aware of just how to look after it. The American Heart Association reports that 400,000 to 460,000 people die each year due to sudden cardiac arrest, with 13 percent of these deaths happening in the workplace.

Should someone suffer a heart attack or sudden cardiac arrest (SCA), timing is everything and chances of survival will dramatically decrease with every passing minute. Despite this, many people still don't understand the differences between a heart attack and SCA. Being educated and understanding just how to respond in an emergency situation can make a life-saving difference and will ultimately determine the survival of the victim.

What is Sudden Cardiac Arrest?
Sudden cardiac arrest is a condition caused by an electrical malfunction in the heart that stops blood from pumping around the body. SCA can occur suddenly, without any warning.

The electrical malfunction will cause chaos to the heart, resulting in its inability to pump blood to the brain, lungs and other vital organs—causing the individual to lose consciousness. Without immediate attention, death can occur within minutes. A study by the Heart Rhythm Society found that SCA claims one life every 90 seconds, making it a bigger killer than breast cancer and AIDS combined.

There can be few symptoms, and in many cases there are no symptoms at all before a victim suffers an SCA. A casualty will collapse suddenly, losing consciousness and showing no signs of breathing.

What Causes Sudden Cardiac Arrest?
The main cause for SCA in adults is a heart attack and strain on the heart. Complications from previously undiagnosed heart conditions can also lead to cardiac arrest. The most immediate cause of sudden cardiac arrest is usually an abnormality in the heart's rhythm, causing a problem with the electrical system of the heart. The heart has its own electrical stimulator and, when this is disrupted, the functions of the heart can start to break down.

What is a Heart Attack?
A heart attack occurs when the supply of blood to the heart is suddenly blocked. This usually happens as a result of a blood clot. Blood is rich in oxygen and is therefore essential to our living. A lack of blood to the heart will cause serious damage to the heart muscle and will often result in death.

The Heart Foundation reports that 720,000 people in the United States alone will suffer from a heart attack each year, and that someone will have a heart attack every 34 seconds. Heart UK also reported that an estimated 17.3 million people globally have died from cardiovascular disease, accounting for 30 percent of all deaths.

Coronary heart disease (CHD) is the leading cause of heart attacks; this is when the major arteries that supply the heart with blood get clogged up with plaques of cholesterol. If the blocked artery can’t restore blood flow quickly, the affected heart muscle will begin to die. During a heart attack, the plaques will cause a blood clot, which then stops the blood supply from running through the arteries to the heart.

Alongside coronary heart disease, other common causes of heart attacks are severe spasms or tightening of the coronary arteries. Spasms can occur due to stress, smoking, or illicit drugs.

How Do They Differ?
People often use the terms heart attack and SCA interchangeably, but they are far from the same. A heart attack is when the blood flow to the heart is blocked, while a sudden cardiac arrest is when the heart malfunctions and is unable to function correctly. Cardiac arrest is an electrical problem, while a heart attack is a circulation problem.

Most heart attacks won't lead to cardiac arrest, however, when a cardiac arrest occurs, a heart attack is one of the most common causes.

How to Prevent a Heart Attack
The most effective way to look after your heart and to help prevent having a heart attack is to eat a healthy and well-balanced diet. Highly processed foods and processed foods high in saturated fats, such as butter and cakes, should be eaten only once in a while.

Eating a small amount of foods containing unsaturated fat will help to increase the level of good cholesterol in your body and help reduce any blockages in your arteries. These foods include avocados, nuts, seeds, and oily fish.

Smoking is another major risk for heart attacks because it can help to raise blood pressure. Taking steps to stop smoking will not only help your overall health, but also have a massive impact in reducing your chances of heart disease.

High blood pressure can have a huge impact on your heart, putting it under extra strain and therefore increasing your chances of a heart attack. Sticking to a healthy diet, moderating your alcohol intake, monitoring a healthy BMI, and exercising regularly will all contribute to maintaining a healthy blood pressure.

How to Prevent Sudden Cardiac Arrest
Again, it's a case of looking after your body. Watching what you eat, regularly exercising, and cutting down alcohol and smoking will have a massive impact on your health and reduce the chances of damaging your heart. For those who have previously suffered from SCA, doctors may suggest an implantable cardioverter defibrillator (ICD). Surgically placed under the skin in the chest or abdomen, electrodes in the ICD connect with the heart’s chambers in order to monitor the heartbeat.

A defibrillator or AED is the only definitive treatment and a victim’s only chance of survival against SCA. A defibrillator is used to provide a shock to the heart and to restore the heart's natural rhythm in the event of SCA. When someone suffers from sudden cardiac arrest, every minute without CPR and defibrillation can reduce the chance of survival by up to 14 percent.

There are two different types of defibrillators: semi-automatic and fully automatic. A semi-automatic will require a button to be manually pushed in order to deliver a shock, while a fully automatic device will deliver the shock itself if required to a victim of cardiac arrest.

Recent statistics show that the chance of survival can increase from 6 percent to an impressive 74 percent when a defibrillator is used within the first 3-5 minutes of collapse alongside effective CPR. As the statistics show, the use of a defibrillator in the case of SCA can really help increase the likelihood of survival. Without immediate treatment, 90 to 95 percent of sudden cardiac arrest victims will die.

Most defibrillator models nowadays come with either an audible narration or visual instructions to help guide you through the process one step at a time. This means that even people who are unaware of how defibrillators work can still use the device. A defibrillator works through electrode pads applied to the patient’s bare chest. These pads are used to transfer electricity from the device to the patient in a safe manner. Through the electrodes, the defibrillator will analyze the patient’s heart to determine whether defibrillation is needed and, if so, will start to charge itself in preparation for delivering a shock.

When the defibrillator has charged itself, an electrical current will be released through the electrode pads, shocking the chest wall or heart. When the defibrillator has shocked the heart, CPR will be required while the device assesses whether a further shock needs to happen.

When a defibrillator has shocked the patient, it's important that the emergency services are called, even if the heart's natural rhythm has been restored, because further emergency treatment will be required.

Knowing the Difference
There is a great need for people to be educated on heart attacks and SCA. By understanding the difference, you can be aware of the warning signs and know how to respond in an emergency, helping to increase chances of survival.

As it is the most vital organ in the body, everyone should be serious about looking after his or her heart. Eating healthy, regularly exercising, and generally looking after the body are the best ways to reduce your chances of suffering a heart attack or an SCA. Education, first aid courses, and accessible defibrillators in the workplace, schools, and public spaces are the best ways to prepare for an unexpected heart injury and provide the highest chance of survival against cardiac arrest.

This article originally appeared in the October 2016 issue of Occupational Health & Safety.