Cardiac arrest is the sudden loss of heart function, leading to shortness of breath and loss of consciousness. Cardiac arrest typically occurs because of a disturbance in the electrical system of the heart, which hampers the pumping action and thereby stops the normal flow of blood to the body.
A cardiac arrest is different from a heart attack, where only a part of the heart muscle is devoid of blood. But a heart attack can often cause a cardiac arrest by hampering the electrical activity of the heart.
A cardiac arrest is a very serious condition and if not treated timely and adequately, it can lead to death. However, with fast, responsive and immediate care such as CPR (Cardiopulmonary resuscitation), defibrillator or chest compressions, chances of survival can be improved until medical care is received.
Causes of Cardiac Arrest
The most common cause of a cardiac arrest is the problem or an irregularity in the heart rhythm. This condition is medically known as arrhythmia and occurs because of disturbance in the electrical activity of the heart.
Generally, in a human body, the heart’s electrical system is responsible for controlling the rate and rhythm of the heartbeat. In case there is a problem in the heart, the heartbeats too fast or too slow or irregularly. Most often such episodes are brief and do not cause much harm. However, in some cases, these irregularities can lead to a sudden cardiac arrest.
Most often the cause of a cardiac arrest is an arrhythmia which occurs in the lower chambers of the heart, called ventricles. The lower chambers receive erratic signals, which causes useless quiver instead of the pumping action of blood.
That said, some heart conditions could also possibly lead to a cardiac arrest. Arrhythmia usually develops in people that have either of the below-mentioned heart disorders. However, it can occur even in people who have no known heart issues.
Some significant heart conditions that can cause cardiac arrest include:
Coronary artery disease: In this type of heart issue, the arteries of the person become clogged or narrow due to build-up of fat and fibrous substances, called plaque. This comprises of cholesterol and other harmful substances that tend to stick to the wall of the arteries and block the flow of blood to the heart muscle. Coronary artery disease can lead to cardiac arrest in many people. Some significant causes that tend to block the arteries include:
- Bad cholesterol
- Consuming trans and saturated fats
- High blood pressure
- High cholesterol
- Obesity and excessive weight
- Smoking tobacco
- Family history
- Increasing age
- Lack of physical exercise
- Drug abuse
Heart attack: A heart attack occurs when a part of the heart muscle diesdue to loss of blood supply, which could be because of various reasons. The most common reason for a heart attack is when an artery supplying blood to a part of the heart is blocked due to a blood clot.Most often heart attacks lead to ventricular fibrillation, which can, in turn, cause a cardiac arrest. Moreover, a heart attack can also cause a scar tissue in the heart that disturb the electrical activity, leading to arrhythmia.
Enlarged heart: Also medically referred to ascardiomegaly,an enlarged heart implies that the heart is bigger than the normal. Typically, a heart becomes enlarged because the muscles work so hard that they thicken or the chambers widen than the normal size. Usually, an enlarged heart is not a disease but is an indication of an underlying disease such as cardiomyopathy, heart valve problems, or high blood pressure. These conditions make the heart work harder and hence, at a point in time, the heart is unable to pump blood into the body as efficiently as required. This can cause complications such as stroke, cardiac arrest or heart failure.
Valvular heart disease: Valvular heart disease occurs when there is a defect in one of the four valves of the heart – the mitral, aortic, tricuspid and pulmonary. A defect such as a leakage or narrowing of any of the heart valves can cause the heart muscle to stretch or thicken. Moreover, when the chambers of the heart become enlarged or weak due to excessive stress caused by a tight or a leaking valve, the electrical system of the heart can be disturbed and lead to arrhythmia. This can, in turn, cause a cardiac arrest.
Congenital heart disease: Congenital heart diseases are disorders of the heart that are present since birth. A few of these disorders such as blood vessel abnormalities can cause cardiac arrest. Blood vessel diseases, particularly of the coronary artery and the aorta, can trigger a sudden cardiac arrest. Due to congenital heart tissue of the blood vessel, adrenaline is released at the time of intense physical activity. This often triggers a disruption in the electrical functioning of the heart, leading to a cardiac arrest.
Electrical problems in the heart: Some people might have issues with the electrical system of the heart rather than the valves or the heart muscle. This is also known as primary heart rhythm abnormalities and is caused due to conditions such as Brugada’s syndrome and long QT syndrome.
Risk factors of cardiac arrest
Some people that are at a higher risk of experiencing a cardiac arrest include:
- People with a family history of coronary artery disease
- People with issues such as high blood pressure, obesity, diabetes, etc.
- People who are inactive and have a sedentary lifestyle
That said, a few other factors can also increase the chances of a cardiac arrest:
- A previous history of cardiac arrest
- A previous heart attack
- Acute kidney disease
- Increasing age
- Consumption of illegal drugs such as cocaine
- Obstructive sleep apnea
- Lack of essential nutrients such as potassium or magnesium
- Congenital heart defects
- Family history of heart issues, cardiomyopathy, heart rhythm disorders, etc.
Overall, a cardiac arrest can be avoided if a person follows a healthy lifestyle and leads an active life avoiding all triggers and risk factors. Regular medical check-ups can also keep a check on heart health.