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Roughly three in four Americans have fainted themselves or know someone who has fainted, according to a national survey by Syncope Trust and Reflex Anoxic Seizures. Syncope, the medical term for fainting or passing out, is a temporary loss of consciousness and could indicate an underlying cardiac condition.

If you ever find that you have fainted, you should seek medical attention as soon as possible after the episode, says Tahmeed Contractor, MD, a cardiac electrophysiologist at Loma Linda University International Heart Institute and Loma Linda University Medical Center - Murrieta. Care providers can determine the cause of your fainting. Contractor says depending on whether you are diagnosed with a certain cardiac condition, you may be at risk of experiencing sudden cardiac arrest in the future if the condition goes untreated.

For October’s Sudden Cardiac Arrest (SCA) Awareness Month, Contactor describes types of fainting, what fainting may signal about your heart health, and why you should seek medical attention directly after experiencing an episode to find out.

Seeing a doctor will help you understand the cause. You might rule out any heart problems, but even if a heart condition is found, you can take the right steps to ensure you're safe from complications in the future.Dr. Tahmeed Contractor

The most common type of syncope is vasovagal: fainting from a sudden drop in heart rate and blood pressure. Contractor describes a typical scenario: It is a hot day, you are dehydrated, and you've been standing for a long time. Suddenly, you feel nauseous, break out in a sweat, your face pales, a feeling of warmth envelops your body, and you gradually black out. In a few seconds, blood flow returns to your brain after being in a horizontal position, and you recover or wake up. After waking, you may feel exhausted.

When the brain senses that the heart is beating hard and blood pressure is high, Contractor says it sends an impulse throughout the body to relax. Blood stops reaching the brain during this maladaptive nervous system response, eventually making you faint.

Contractor warns to seek medical attention after any fainting episode, even if you suspect the cause was fatigue, heat, dehydration, or an emotional response.

“Sometimes a faint might seem vasovagal, but once you dive deeper, testing could reveal an underlying health concern,” Contractor says. “You want an expert to make this diagnosis and figure it out.”

If you experience this type of fainting frequently, Contractor says you will likely work with your care provider on lifestyle changes such as staying hydrated and wearing compression stockings. In some cases, he says you may wear a heart rhythm monitor to track your heart rate; based on the results, you and your physician will decide on the best treatment plan moving forward. For example, medications to raise blood pressure could help reduce fainting spells, Contractor says. In addition, a subset of patients could benefit from the implantation of a pacemaker, a small device placed in the chest to help control the heartbeat.

Other syncope scenarios that Contractor describes as “highly concerning” involve fainting out of the blue, without any symptoms (prodrome) during a period of inactivity — like sitting on the couch watching television — or in the midst of physical activity — like running across a basketball court and suddenly passing out.

These bouts of fainting may indicate the presence of cardiac arrhythmia, Contractor says. Arrhythmias occur when electrical impulses in the heart don't work properly, causing an improper beating of the heart, whether irregular, too fast, or too slow. Arrhythmias are the most common cause of sudden cardiac arrest — the unexpected loss of heart function, breathing, and consciousness — according to the American Heart Association.

Read: Facts to know about sudden cardiac arrest that could save lives

In these cases, Contractor says visiting the emergency department is the quickest way to obtain medical care. “You could faint again in a matter of minutes or hours,” he says. “You should be evaluated as soon as possible after the first episode, not five days later.”

The bottom line is, don’t blow off a faint.Dr. Tahmeed Contractor

The evaluation consists of testing via an electrocardiogram, an ultrasound of the heart, and possibly a heart rhythm monitor or coronary angiogram. Contractor says results from imaging will determine whether you need to undergo a cardiac MRI, receive an implantable cardioverter-defibrillator (ICD) to detect and stop irregular heartbeats, or obtain a pacemaker.

Someone who experiences this type of fainting may possess a slow heart rhythm that is malignant and requires a pacemaker, or they may be at risk for ventricular fibrillation — a life-threatening, fast heart rhythm from the heart’s bottom chamber. With ventricular fibrillation, the heart beats so fast that it doesn't produce adequate blood flow to the brain. This type of arrhythmia is the most common one to cause cardiac arrest, Contractor says, and can cause irreversible brain damage and death.

“The bottom line is, don’t blow off a faint,” he says. “Seeing a doctor will help you understand the cause. You might rule out any heart problems, but even if a heart condition is found, you can take the right steps to ensure you're safe from complications in the future."


Physicians at LLUMC - Murrieta and the International Heart Institute are committed to providing patients with compassionate, comprehensive, and personalized cardiovascular care. Call 1-800-468-5432 to make an appointment.