Sudden Cardiac Arrest, in Young People.

What sudden cardiac arrest is — and what it is not.

Sudden cardiac arrest (SCA) is an electrical malfunction of the heart. The heart's rhythm becomes chaotic — most often a condition called ventricular fibrillation — and the heart can no longer pump blood. The person collapses. Without immediate CPR and defibrillation, death follows within minutes.

A heart attack is different. A heart attack is a plumbing problem — a blockage in an artery that supplies the heart muscle. The person is usually conscious. They feel pain. They can call for help. Most heart attacks do not cause sudden death.

Both are emergencies. They require different responses. The American Heart Association notes that while most heart attacks do not lead to cardiac arrest, a heart attack is one of the more common causes when cardiac arrest does occur. But in young athletes, the cause is almost never a blocked artery. The cause is almost always a structural or electrical condition the person was born with — often undiagnosed until the moment of collapse.

Why young, healthy athletes.

The conditions that cause sudden cardiac arrest in young people are usually congenital — present from birth — and silent. The athlete passes a school sports physical. They play at a high level. They have no symptoms their family or their pediatrician recognizes.

The most common conditions associated with sudden cardiac death in young athletes include:

• Hypertrophic cardiomyopathy (HCM) — a thickening of the heart muscle. The condition that took Chase.
• Anomalous coronary artery — a coronary artery that arises from the wrong location.
• Long QT syndrome — an inherited electrical disorder.
• Wolff-Parkinson-White syndrome — an extra electrical pathway in the heart.
• Arrhythmogenic right ventricular cardiomyopathy — a progressive disease of the heart muscle.
• Commotio cordis — a blow to the chest at a precise moment in the heart's cycle.

With the exception of commotio cordis (which is a freak event), every condition above is detectable through a screening protocol that includes both an electrocardiogram and an echocardiogram, interpreted by a physician trained in athlete-specific cardiac criteria. The foundation's screening program follows exactly that protocol.

If it happens, recognize it. Act.

Witnesses to sudden cardiac arrest in young athletes often misread what they are seeing. Roughly half the time, the collapse is accompanied by gasping breaths or seizure-like shaking, and the response of bystanders is to assume a seizure or a fainting spell and to wait. Waiting kills.

Dr. Jonathan Drezner — co-author of the international screening criteria the foundation follows — has documented this repeatedly: any collapsed athlete should be assumed to be in sudden cardiac arrest until proven otherwise.

Field signs of SCA

• — Sudden collapse, particularly during or immediately after activity
• — Eyes open or rolled back
• — Seizure-like shaking, often misread as a seizure
• — Gasping or noisy breathing (agonal respirations) — often mistaken for normal breathing
• — Unresponsive to voice or touch

What to do

1. Call 911 immediately. Do not wait to see if the person recovers.
2. Send someone for an AED if one is available on site.
3. Begin CPR immediately — chest compressions, hard and fast, in the center of the chest.
4. Use the AED as soon as it arrives. AEDs are designed for non-medical bystanders. Follow the audio prompts.
5. Continue CPR until emergency medical services take over.

Survival from out-of-hospital sudden cardiac arrest drops by approximately ten percent for every minute that passes without CPR or defibrillation. The American Heart Association reports that bystander CPR can double or triple the chances of survival. There is no waiting room in this emergency. Acting wrongly is better than not acting.