Last weekend I got a call from daughter while I was enjoying dinner on the deck at home. The young man sitting next to her had collapsed during dinner. ”What should we do?” was the question. Being an astute family physician I immediately told her to call 911. Fortunately that call to 911 had preceded the call to Dad. My next question was is he breathing and does he have a pulse. I was assured that another friend knew CPR and had already made a quick assessment and was doing CPR. The ABC’s were being addressed. Before I could do more than be pleased and proud of the exemplary initial response of the young persons at the scene paramedics arrive. What sounded like defibrillation and intubation preceded transportation to the emergency department. Thankfully sudden cardiac arrest is uncommon in young prople, but this case so close to home prompted me to discuss sudden cardiac arrest in youthhere on DrPullen.com. We all think of sudden cardiac arrest as something that occurs to older persons, or sometimes to relatively young persons in their late 30’s or 40’s. In these not-as-young persons the usual cause of sudden death is coronary artery disease, or sometimes complications of conditions like congestive heart failure. Often in people with undiagnosed coronary artery disease sudden cardiac arrest can be the initial symptom (1). Overall sudden cardiac arrest is a fairly common cause of death in older Americans. When sudden cardiac arrest occurs unexpectedly in a person under age 30 the usual underlying conditions are usually different.
When I think of sudden cardiac arrest in a young person the first question is whether the event happened during exercise or at rest. Three medical conditions are thought to be the usual underlying causes of sudden cardiac arrest in young persons, two of which usually occur during exercise. Let’s consider these first.
Hypertrophic Cardiomyopathy: When the cardiac arrest occurs during exercise the most common cause is a condition called Hypertrophic Cardiomyopathy or Asymmetric Septal Hypertrophy. In this condition the part of the left ventricle, the main pumping chamber of the heart, is thickened so that during maximum exercise when the heart needs to receive the most oxygen it can become oxygen deprived, or ischemic. This can result in a cardiac arrhythmia causing collapse and even sudden death. Warning signs of this condition can be fainting during maximal exertion, or severe lightheadedness and near fainting in these situations. Hypertrophic cardiomyopathy is felt to be the most frequent cause of cardiac arrest and death in young athletes, and is often unsuspected and undetected prior to the event.
Coronary Artery Anomolies: Abnormalities of the coronary arteries that lead to poor circulation of the heart during exercise is another cause of sudden cardiac arrest in young persons. This is considerably less common than hypertrophic cardiomyopathy, but like hypertrophic cardiomyopathy this condition usually leads to arrest during exercise.
Long QT Syndrome:
When sudden cardiac arrest occurs in an otherwise healthy young person at rest a condition called Long QT syndrome is often the cause. This is a condition that is often familial, sometimes called the Romano Ward-Syndrome an autosomal dominant condition with variable penetrance, and can lead to a cardiac arrhythmia called Torsade de Pointes,
where a chaotic rapid heart rate that can deteriorate into ventricular tachycardia or ventricular fibrillation can occur. The term QT refers to the part of an electrocardiogram that occurs during the resting time of the heart after a heartbeat, called repolarization. This time is when the heart is most at risk for a premature heartbeat that happens randomly and can trigger a serious cardiac arrhythmia if it happens during the QT period. Sometimes this type or cardiac condition can cause what appears to be a seizure rather than a cardiac arrest, and can lead observers to describe a seizure rather than a cardiac arrest. Sometimes when evaluation for a seizure is not fruitful, the diagnosis of prolonged QT syndrome is not suspected. Many medications can make the QT segment longer, and in individuals who have a long baseline QT these drugs can be especially dangerous. When multiple medications that can lead to QT prolongation are used together the risk can be higher. Still, most of the time in young people, medications do not play a role in long QT related cardiac arrest.
What can you do to prevent sudden cardiac arrest in your child or a young person? Unfortunately all too often the answer is probably nothing, but some situations should lead to evaluation. There is controversy over routine screening of youth with an EKG or echocardiogram prior to vigorous sports activity. Most experts would agree that first degree relatives of anyone with prolonged QT syndrome or hypertrophic cardiomyopathy should be evaluated for that condition. In the case of prolonged QT this is just an EKG. In hypertrophic cardiomyopathy an echocardiogram is the usual screening tool. If severe lightheadedness or fainting during exercise occurs evaluation for hypertrophic cardiomyopathy should be suspected and an echocardiogram done to screen for this condition. If there is an unexplained sudden death in your immediate family prior to age 50 consideration of evaluation of young persons in the family may be considered.
Fortunately my daughter’s friend has survived their sudden cardiac arrest. Unfortunately this is not always the case. The Puget Sound has historically had terrific 911 service and very fast emergency worker response times which likely saved a life in this case. Hopefully this discussion will raise awareness in readers of symptoms in our youth that can warn of sudden cardiac arrest.