Cardiac Arrest: 8 Signs & Symptoms

The heart is an organ that is vital to sustaining life. Diseases and malfunctions of the heart are some of the highest reasons for mortality in the modern world. Heart disease, heart attack, arrhythmia, hypertension, heart failure, and atherosclerosis are some of the most common conditions that impact the heart.

While all of these conditions impact the heart differently, they can all cause irreversible damage and dysfunction to the point that it stops beating.

Below is a closer look at cardiac arrest and some of the common signs and symptoms.

What Is Cardiac Arrest?

Cardiac arrest is often confused with a heart attack, but cardiac arrest and a heart attack, also known as a myocardial infarction, are not the same. Both are considered emergent cardiac events, but cardiac arrest entails a heart that is no longer beating or pumping blood.

Cardiac arrest occurs when the heart stops beating altogether, while a heart attack can occur when the heart is struggling to function properly due to reduced blood flow. Eventually, cardiac events like heart attacks can lead to cardiac arrest, but it is important to distinguish cardiac events from complete arrest.

There are a number of heart conditions that can lead to cardiac arrest aside from a heart attack. These include congenital heart defects, abnormal heart rhythm, coronary artery disease, heart failure, high blood pressure, and injuries.

The main treatment for cardiac arrest is quality cardiopulmonary resuscitation (CPR) and the prompt use of an automated external defibrillator (AED), which can shock and “restart” an unproductive heart rhythm. The long-term outlook and chances of survival for an individual whose heart stops beating are generally dim, especially when cardiac arrest occurs outside of a hospital setting.

The best chance of survival is achieved with the prompt initiation of an EMS response, quality chest compressions from bystanders, and appropriate post-arrest care.

What Are the Signs and Symptoms of Cardiac Arrest?

When an individual enters cardiac arrest, blood is no longer flowing through their body as it should. This means that the brain and other organs are not getting the oxygen and nutrients they need to function, making it highly likely that these tissues will die without prompt resuscitation efforts.

Getting timely treatment for cardiac events can significantly reduce the chance of cardiac arrest and help improve overall outcomes. By familiarizing yourself with the signs and symptoms of cardiac events, you could save someone's life.

1. Loss of Consciousness

The brain is one of the most resource-hungry organs in the body. The organ only makes up 2% of the mass of an average adult, yet it utilizes nearly 20% of the oxygen you breathe in a day. This high demand means that your brain needs a constant and steady blood supply to ensure it can function.

For the reasons mentioned above, the brain is one of the first organs to become affected by reduced circulation and supply of blood. A cardiac event, whether it is total cardiac arrest or reduced heart efficiency, can directly cause a lack of oxygenated blood to reach the brain. This lack of oxygen can impair brain function, resulting in a loss of consciousness.

A loss of consciousness, however, can be caused by a number of variables ranging from life-threatening, as is the case with cardiac arrest, to relatively benign. If you witness someone lose consciousness or if you lose consciousness, you should treat it as a medical emergency until the cause is determined.

2. Shortness of Breath

Another organ that is closely tied to the heart is the lungs. The lungs and heart work together to create the pulmonary circuit of the circulatory system, which is responsible for reoxygenating blood. The pulmonary circuit is one of two pathways of blood throughout the body, and it can be affected by cardiac events.

The right side of the heart is responsible for pumping unoxygenated blood coming from the body to the lungs. Once this blood enters the lungs, gas exchange occurs, resulting in reoxygenated blood. This blood then enters the left side of the heart, where it is pumped to the rest of the body’s tissues.

A weakened right side of the heart, a blockage in the path of blood in the lungs, or an impaired left side of the heart can result in shortness of breath.

3. Extreme Fatigue

The body requires a steady supply of oxygen and nutrients to function at its very best, and when these demands are not met, it can lead to symptoms like severe fatigue.

Extreme fatigue has many potential causes, but it can be indicative of a cardiac event, especially in individuals with a history of cardiac issues such as heart failure.

4. Heart Palpitations

A heart palpitation is another way of referring to a heart arrhythmia. Heart palpitations can be normal, and many healthy individuals experience heart palpitations here and there. However, prolonged irregular heartbeats can be an indication of a cardiac event.

A heart that is beating too fast (tachycardia), too slow (bradycardia), or ineffectively can all be indicators of a cardiac event. If you’re worried about your heart palpitations, or if they occur alongside other symptoms, seek medical attention to rule out any serious condition.

5. Dizziness or Lightheadedness

A crucial aspect of your cardiovascular health is blood pressure, and some cardiac events can drastically lower your blood pressure. Healthy blood pressure allows blood to reach all the tissues of the body, and blood pressure that is too high or too low can impair your overall bodily function.

If you have ever felt lightheaded or dizzy upon standing up, it is likely that in those moments, your blood pressure was not high enough to fight against gravity and maintain blood flow to your brain. These situations tend to self-correct as the heart compensates, but a similar sensation can be felt during a cardiac event where the heart cannot pump blood efficiently.

6. Nausea

Nausea is not typically a symptom that people associate with cardiac issues, but cardiogenic nausea is indeed a sign of cardiac events.

The exact physiological pathway for why vomiting and nausea occur in some individuals during a cardiac event is not known, but it is a symptom to look out for, especially if it is accompanied by other symptoms like chest pain.

7. Chest Pain

Chest pain is the single most important symptom when it comes to identifying cardiac events — especially heart attacks and cardiac arrest. The body’s innate pain response is there to signal to you when something is wrong or tissue is being damaged.

Pain or a crushing sensation in the chest can indicate that the muscles of the heart are being starved of oxygen due to a blockage of the coronary artery and a lack of blood flow to the heart.

Chest pain that occurs without warning should be checked by a healthcare professional, as it could indicate that your heart is in distress which, if left untreated, could lead to cardiac arrest.

8. Weakness

The muscles in your body are vascular and require a steady supply of oxygen and glucose to function.

Each muscle contraction requires energy, and when blood supply is limited due to a heart that is pumping ineffectively, it can reduce the strength of these contractions and lead to generalized weakness.

When Should You Consult a Doctor?

When it comes to the heart, it is always safer to seek medical consultation sooner rather than later. Experiencing just one symptom of a cardiac event might not signify anything serious, but it could be a sign that your heart is struggling to function.

Getting checked out by a healthcare professional is the only true way of discerning between a serious health event and a mild inconvenience.

Preventative Care

You should also consider consulting with your doctor if you have a family history of cardiac problems or if you have been diagnosed with a cardiac issue such as heart failure or heart disease.

Consulting your doctor early to find ways to improve your cardiovascular health is one of the best things you can do to help mitigate your chances of more severe complications.

One option is cardiac rehab. Cardiac rehabilitation is designed to help improve your overall cardiovascular health through a number of different interventions, such as health education, monitored exercises, and lifestyle modifications. Traditionally, these services were only available at specialized rehab facilities, but Carda Health offers these same services from the comfort of your home.

The process is easy — simply fill out a questionnaire, get authorization from your cardiologist or health care provider, and you could be on your way to getting a tailored cardiac rehabilitation program right from the comforts of your own home.

The Bottom Line

Cardiac arrest occurs when the heart stops beating. Time is of the essence when it comes to getting the treatments necessary to restart the heart.

The main signs someone is in cardiac arrest are a sudden loss of consciousness and a lack of pulse. There may also be a number of symptoms that precede cardiac arrest, including shortness of breath, unexplained sudden fatigue, heart palpitations, dizziness, nausea, and weakness.

Identifying the symptoms of a potential cardiac event is important and can allow a person to get prompt care and potentially avoid more severe cardiac complications and can even save one's life.


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