Heart Attack, Cardiac Arrest, Heart Failure: Are They the Same or are They Different?

Heart Attack, Cardiac Arrest, Heart Failure: Are They the Same or are They Different?

Often confused with one another – heart attacks, cardiac arrest, and heart failures are actually three different heart conditions. While correlated, they all demonstrate different characteristics that make them clearly distinct from one another and are thus, not interchangeable.
But before that, it’s important to – at least briefly – understand the heart, its function, and how it works.

The Heart

Heart and blood flow diagram by Michigan Medicine

The heart is a hollow, muscular organ (muscle) approximately the size of an adult’s fist. Separated into two halves, left and right; each half is further separated into a top chamber called the atrium and the bottom chamber called the ventricle, making four chambers in total – the right atrium, right ventricle, left atrium, and left ventricle.

The heart also contains valves and is further surrounded by an intricate network of blood capillaries and nerve tissues that help it function, enabling it to supply oxygen and nutrients to other organs by  pumping blood throughout the body. This complex system involving the heart and blood vessels is called the cardiovascular system.

Each time the heart beats, it receives deoxygenated (low oxygen) blood in the right side and pumps it to the lungs, where the blood gets oxygenated (oxygen rich). This freshly oxygenated blood is then sent to the left side of the heart and pumped through the body.

 

Heart Attacks (Myocardial Infarction)

The most well-known amongst the 3 conditions, heart attacks are a “circulatory” issue that occur when blood flow to the heart is either fully or partially blocked, usually within the coronary arteries. This can be due to a number of reasons including a sudden artery spasm, blood clot or build-up of plaque. When this happens, sections of the heart that are deprived from oxygen-rich blood become damaged, thus unable to effectively pump blood. If treatment is not administered as soon as possible, the entire heart muscle dies. 

As such, heart attacks are considered to be an extremely serious condition that should not be taken lightly. In fact, according to the TheStar Newspaper, heart attacks have been considered the leading cause of death in Malaysia for the past 17 years.

Cardiac Arrest

A cardiac arrest on the other hand is an “electrical” malfunction of the heart that causes the heart to beat irregularly (arrhythmia) or stop beating entirely. It is considered “electrical” because in order to contract (beat) and pump blood, an electrical impulse is generated by what is known as the heart’s sinus node or sometimes called sinoatrial node (SA node). This electrical signal not only generates a heartbeat, it also determines heart rate (how quickly the heart beats).

It’s important to understand that while a heart that no longer beats is clearly unable to deliver blood, a heart that beats chaotically, dangerously fast, or even too slow can also have a similar effect as the heart is unable to deliver sufficient blood to itself and the rest of the body. Within just minutes, death can occur – but with quick action, a cardiac arrest can actually be reversed. 

Although cardiac arrests tend to occur suddenly and without warning, it is usually triggered by an existing medical issue or a possible physical trauma. Heart attacks for example, are a common cause of cardiac arrests; but not all heart attacks lead to a cardiac arrest. Due to this reason, a cardiac arrest can sometimes be misdiagnosed or confused as a heart attack.

 

Heart Failure

Heart failures are neither specifically circulatory nor electrical and can be due to a large number of reasons. As explained in the earlier section, the heart acts as a pump that delivers blood throughout the body. When the heart is unable to effectively pump as much blood as the body needs, it is considered to be inefficient. This inefficiency is known as heart failure – and despite the possible implication of its name, it does not actually mean that the heart has stopped and is no longer able to function. It just means that the heart is no longer working at its optimum level.

Since the heart no longer pumps normally, the body and nervous system tends to compensate for the lack of blood in various ways including raising blood pressure and causing the heart to beat faster, eventually leading to arrythmia and a cardiac arrest. Incidentally, the leading cause of heart failure is usually due to other heart diseases such as coronary artery disease, hypertension, congenital heart defect and more; and is thus considered a long-term and chronic condition that is progressive. That being said, heart failures can also be acute and unpredictable, whereby they occur suddenly due to injuries or an infection.

In Malaysia, heart failures account for almost 6-10% of all acute medical admissions with a quarter of heart failure patients being readmitted within just 30 days. Coronary artery disease and hypertension accounts for almost 70% of all cases and appear to be the main cause of heart failure in most adult Malaysians.

Summary

In essence, a heart attack is a “circulatory” issue whereby blood flow to the heart has been blocked, while a sudden cardiac arrest occurs due to an “electrical” malfunction that causes the heart to either stop beating or to beat erratically. Heart failure on the other hand, is a weakened heart that is no longer able to pump blood efficiently, thus affecting the heart’s efficiency.

All 3 heart conditions are dangerous and can come without warning, but a quick daily check of your heart pressure can minimize the potential risks as any abnormality in blood pressure can indicate an ongoing or future issue.  

Don’t wait. Invest in your very own electronic blood pressure monitor today – because your health is wealth.

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