Sudden Cardiac Arrest – When the Heart Stops

In January 2023, the sudden collapse and subsequent resuscitation on the field of NFL player Damar Hamlin brought to harsh light the uncommon phenomenon of sudden cardiac arrest in apparently healthy young athletes. It also brought confusion to many people who lacked understanding of what cardiac arrest actually is, what may cause it, and how it may be prevented. 

The threat of sudden cardiac arrest is one of the primary reasons for youth sport clearance exams. While it is rare, there are cases every year of young athletes suddenly collapsing while playing a sport, a fact that is devastating in the extreme. These deaths leave family members and communities in shock – how can this happen in a young, healthy child? Fortunately, there are ways to help prevent some of these cases, by identifying risk factors that prompt further evaluation. 

What is Sudden Cardiac Arrest?

Before we delve further into these risk factors, it is important to understand what, exactly, sudden cardiac arrest is and how it is caused. Sudden cardiac arrest is the abrupt loss of heart function – meaning that the heart suddenly stops working the way it is supposed to. It may continue to beat, but in such a disorganized and uncoordinated way that no blood flow results. This results quickly in loss of consciousness due to lack of oxygen to the brain. If not acted upon immediately, this condition quickly leads to death. Survival of sudden cardiac arrest depends on immediate response by those around, including CPR and defibrillation while emergency responders are called. Sudden cardiac arrest is NOT what many people traditionally think of as a heart attack, which is a blockage of blood flow to the heart muscle, though a heart attack can lead to cardiac arrest as well. 

What Causes Sudden Cardiac Arrest?

For today’s purposes since this is a Pediatric-focused blog, we will discuss the most common causes in young people. 

• Arrhythmia – this is a condition where the heart rhythm is abnormal. If the rhythm is abnormal, the heart does not beat effectively and this can impair blood flow out of the heart to the body. There are a few known genetic heart arrhythmias that can lead too sudden cardiac arrest: Long QT syndrome and Wolff-Parkinson-White syndrome.

• Hypertrophic cardiomyopathy (HCM) – this is a typically inherited condition that causes thickening and enlargement of the heart muscle in the lower chambers of the heart. It can cause abnormal heart rhythms as well as obstruction of blood flow out of the heart. HCM is the most common cardiovascular cause of sudden cardiac arrest in young athletes.

• Coronary artery abnormalities – this is an abnormal connection of the artery that supplies the heart muscle with blood. This can lead to decreased supply of blood (and therefore oxygen) to the heart muscle, causing injury and death of that muscle and lead to sudden cardiac arrest. There may be symptoms of chest pain associated with exercise in this condition. 

• Myocarditis – this is inflammation of the heart walls. This is usually triggered by an infection, but can also be cause by allergic reactions to some medications. Myocarditis usually causes chest pain, fatigue, heart palpitations, and shortness of breath. 

• Marfan syndrome – this is a genetic condition that affects the connective tissue of the body and can lead to problems with the aorta. Children with this condition must be evaluated by cardiology prior to sports clearance. 

• Commotion cordis – this occurs due to a sudden strike to the chest above the heart, at just the right moment to disrupt the cycle of the heart and make it stop. There is not a genetic predisposition to this occurring. It is more commonly associated with sports that involve fast-moving projectiles, such as baseball or hockey. 

Risk Factors for Sudden Cardiac Arrest

• Family history is probably the biggest risk factor for early cardiac arrest. It is one of the most important reasons that sports physicals are to be done as part of a comprehensive evaluation. Providers will ask about any family history of sudden, unexplained death in the family, particularly in young people. 

• Known medical conditions such as arrhythmia and coronary artery abnormalities, as discussed above. These children should have evaluations by a Pediatric Cardiologist prior to clearance for sports activities. 

• Symptoms of cardiac dysfunction such as chest pain with exercise, unexplained shortness of breath, or fainting spells during exercise. 

Unfortunately, not all cases of sudden cardiac arrest have an identified cause. However, knowing the risks and family history of those listed above can make a huge impact on early identification. 

What Can Be Done?

Above all, know your family risk factors and discuss these with your Pediatrician. This is particularly important prior to your child participating in sports activities, but in truth, if there is a concerning family history it is necessary for your child to be evaluated for treatable issues whether he or she participates in sports or not. 

Become CPR certified. It is not difficult and it can save a life. 

Be aware of where the AED (Automated External Defibrillator) is located if you are at an event. Early and appropriate use of these machines make the difference between survival and death in cases of sudden cardiac death. 

Final thoughts

We hear about it: the basketball player that collapses while playing in a game. The Little League player who gets hit by a pitch and goes down unresponsive. These are examples of sudden cardiac arrest that we never want to think about…but we must. Knowledge is power and can be life-saving. We do not ever want to miss an opportunity to prevent sudden cardiac arrest, or to be quick to respond and treat it if it occurs unexpectedly. Talk to your Pediatrician.  Make sure your child is up to date on well checks and receives sports clearance evaluations. Take a CPR class, particularly if you are involved in youth activities. Check to be sure your child’s clubs and groups have an AED present at all event locations. 

It’s the small preventative measures that have the potential to make a big difference in the lives of all children, but particularly those at higher risk. 

Resources

Sports clearance exams:https://www.astheygrow.blog/sports-clearance-exams-for-young-athletes/

More info on Sudden Cardiac Arrest from the AAP: https://www.healthychildren.org/English/health-issues/injuries-emergencies/sports-injuries/Pages/Sudden-Cardiac-Death.aspx

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