Cardiovascular Syncope (Fainting): What You Need to Know

Syncope is another word for fainting. A person faints when their blood pressure drops and reduces the flow of blood to the brain. While fainting — especially in children — can be very frightening, most children who experience a fainting spell don’t have a serious underlying health condition. In the midst of a temper tantrum, for example, a toddler may hold their breath long enough to induce a fainting spell. On a hot day, a high school athlete who has forgotten to hydrate or eat may pass out during practice. 

Rarely, however, syncope can be a sign of an underlying cardiovascular condition, such as an arrhythmia, congenital heart disease or cardiomyopathy. In these cases, prompt evaluation by a pediatric cardiologist is critical. Below, Emmanuelle Favilla, MD, attending physician in the Division of Cardiology at Children’s Hospital of Philadelphia (CHOP), explains what to look out for and when to call your child’s pediatrician.

Cardiovascular syncope

Fainting spells can sometimes be the first warning sign of an undiagnosed heart disease. Heart conditions associated with fainting can include:

• Arrhythmia, or irregular heartbeat, including bradycardia (too slow) or tachycardia (too fast)
• Structural heart defects
• Functional heart disease, such as cardiomyopathy or myocarditis

Warning signs of cardiovascular syncope

Most children will experience similar symptoms before they faint. These symptoms include:

• Dizziness
• Lightheadedness
• Nausea
• Changes in vision
• Cold, damp skin

However, there are a few specific warning signs that could suggest a more serious condition. “Syncope with exertion raises a red flag,” says Dr. Favilla. “If a person is playing sports and falls to the ground mid-stride, they should be immediately evaluated for serious cardiac conditions.”

Other red flags include:

• Fainting during high emotional stress
• Fainting accompanied by chest pains and/or heart palpitations
• A family history of sudden cardiac arrest, arrhythmias or cardiomyopathy

If your child has experienced fainting spells associated with any of these warning signs, it’s important that they be evaluated by a pediatric cardiologist right away.

"The most important thing is to seek care in the moment," Dr. Favilla says. "A child who passes out with exertion or soon thereafter should be, of course, resuscitated and stabilized. However, they also need to be promptly evaluated by a cardiologist and restricted from exertion until cleared by the appropriate medical providers. Never hesitate to contact someone if there's syncope with sports or with any rigorous activity, or with chest pain or heart fluttering. These are the red flags we want parents and the community to be vigilant about."

When your child needs to see the cardiologist

If your child is referred to a pediatric cardiologist, they will likely undergo several heart tests, including an electrocardiogram (ECG), which will look at the heart rhythm to see if there are any abnormal electrical patterns. Your cardiologist may also recommend an echocardiogram, which is a targeted ultrasound of the heart, to look for structural and functional abnormalities. Based on the child’s medical and family history, as well as the characteristics of the syncope, the exam may include bloodwork, an exercise stress test and/or a cardiac MRI.

Pediatric Holter monitors are also used to diagnose underlying arrhythmias. A Holter monitor is a device that is connected to your child’s chest by electrodes and can be worn for a period of days while your child resumes their normal activities. “Depending on the frequency of episodes, I would probably place a one- or two-day monitor, or even up to a 30-day monitor or longer if the syncope is associated with factors concerning for an arrhythmia,” says Dr. Favilla.

The good news is that most underlying causes of cardiovascular syncope are treatable. Depending on your child’s diagnosis, treatments may include medication, surgery, lifestyle changes, or even implantable devices, such as a pacemaker or implantable cardioverter defibrillator.

If you’re worried that your child’s fainting episodes may be related to an underlying heart condition, it’s best to err on the side of caution and contact your child’s pediatrician. Says Dr. Favilla, “It is difficult and scary for a parent to witness their child having syncopal episodes. It’s important to partner with a care provider to determine if any of these red flags in the personal or family history would benefit from further evaluation.”