When one young athlete’s cardiac arrest revealed a family at risk

A teenage girl was participating in a track event when she suddenly collapsed. Within moments, an ordinary school athletic event became a medical emergency: she was in cardiac arrest. People at the scene recognized the emergency and began resuscitation. Emergency medical services responded, and she was successfully resuscitated. For everyone involved, her survival was the immediate victory. For those of us caring for her afterward, however, an important question remained: Why would the heart of an apparently healthy teenage athlete suddenly stop during exercise? Finding the answer would ultimately do much more than explain one young athlete’s cardiac arrest. It would uncover an inherited rhythm disorder affecting multiple members of her family and, years later, another generation.

A hidden electrical disorder

When we think about serious heart disease in children, we often imagine a structural problem: a congenital heart defect, an abnormal valve, or disease of the heart muscle. Yet some potentially life-threatening conditions involve the heart’s electrical system rather than its structure. This young athlete was ultimately diagnosed with catecholaminergic polymorphic ventricular tachycardia (CPVT), a rare inherited rhythm disorder in which exercise or intense emotional stress can trigger dangerous ventricular arrhythmias. One of the most common forms of CPVT is inherited in an autosomal-dominant pattern and is associated with variants in the RYR2 gene, which plays an important role in calcium regulation within heart muscle cells.

What makes CPVT particularly challenging is that the heart may appear completely normal between episodes. The structure of the heart may be normal. The resting electrocardiogram may also be normal. A young person can feel well, participate in sports, and have no outward indication of heart disease. The risk becomes apparent when adrenaline rises. During strenuous exercise or intense emotional stress, abnormal ventricular beats can develop and become progressively more complex. In susceptible patients, these arrhythmias can progress to ventricular tachycardia and, in the most severe circumstances, cardiac arrest. For this young woman, a track event exposed an electrical vulnerability that had otherwise remained hidden.

One diagnosis, an entire family

Once we identified an inherited rhythm disorder, our responsibility extended beyond the patient who had survived the cardiac arrest. We needed to look at her family. Because her form of CPVT was inherited in an autosomal-dominant pattern, close relatives could have the same condition even if they had never experienced a cardiac arrest or other obvious cardiac symptoms. The family underwent screening. Her mother and two siblings were subsequently diagnosed with the same condition. What began with the cardiac arrest of one young athlete had revealed an inherited rhythm disorder affecting four members of the same family. All four ultimately received implantable cardioverter-defibrillators as part of their individual management.

But the story did not end with that generation. Years later, the young athlete grew into adulthood and became a mother. After the birth of her daughter, screening showed that her daughter had also inherited the familial genetic condition. The contrast between mother and daughter illustrates why recognizing inherited cardiovascular disease matters. The mother’s condition was discovered only after she experienced a cardiac arrest during a track event. Her daughter’s risk was identified before a life-threatening event occurred. She can now be followed as she grows, with careful assessment of her symptoms, heart rhythm, and response to exercise. Treatment can be individualized as her clinical course evolves, including additional therapies if they become necessary. Her mother’s diagnosis came after a cardiac arrest. Her daughter begins with something very different: knowledge of the risk and an opportunity for surveillance and prevention.

From 1 patient to 3 generations

This is the value of cascade screening. When an inherited cardiovascular disorder is identified, evaluation should not necessarily stop with the person in whom the disease was first recognized. Appropriate first-degree relatives—including parents, siblings and children—may also need evaluation. When a disease-causing genetic variant has been identified, targeted genetic testing can help determine which relatives have inherited the same variant. Clinical evaluation may also include electrocardiography, exercise testing and ambulatory rhythm monitoring.

The implications can be profound. A relative may feel perfectly healthy. A child may run and play normally. A routine physical examination may reveal nothing unusual. Yet that person may carry the same inherited susceptibility to a potentially dangerous arrhythmia. In this family, one cardiac arrest ultimately led to recognition of an inherited condition across three generations. That changes the purpose of diagnosis. We are no longer simply trying to explain why one patient’s cardiac arrest occurred. We have an opportunity to identify another person at risk before the first serious event.

It matters when symptoms occur

This case also illustrates an important principle in evaluating young athletes: the circumstances surrounding a fainting episode matter. Fainting is common in adolescents, and most episodes are not caused by dangerous heart disease. Loss of consciousness during exercise, however, deserves particular attention. Exertional palpitations, unexplained seizure-like episodes, recurrent dizziness with exercise, and a family history of unexplained sudden death are also important warning signs.

CPVT demonstrates why. The electrical abnormality may not be apparent while a patient is sitting quietly in a physician’s office. Sometimes the important question is not simply what the resting ECG looks like, but what happens to the heart rhythm when the heart rate and adrenaline level rise. Exercise testing can be particularly valuable because it may reveal ventricular arrhythmias that are absent at rest and can help assess response to treatment over time. For a young athlete with concerning symptoms, understanding when those symptoms occur can be as important as understanding the symptoms themselves.

Survival begins where the cardiac arrest happens

There is another lesson from this young woman’s story that should not be overshadowed by the eventual diagnosis. Before specialized cardiac evaluation, genetic testing, medication, or an implanted defibrillator could help her, she had to survive the initial cardiac arrest. She survived because people around her recognized the emergency and acted.

Sudden cardiac arrest is extraordinarily time-sensitive. Schools and athletic programs should have emergency action plans that allow rapid recognition of cardiac arrest, activation of emergency medical services, immediate cardiopulmonary resuscitation, and prompt access to an automated external defibrillator (AED). Simply having an AED somewhere on a school campus is not enough. It must be readily accessible, and coaches, teachers, and athletic personnel should know how to respond. Emergency plans should be established and practiced before an emergency occurs. The response at this athletic event gave a young woman something that even the most advanced medical care cannot replace once it is lost: time. It allowed us to determine why her heart had stopped.

Treatment is more than a defibrillator

For patients with CPVT, preventing another event requires ongoing management. Treatment may include medications that reduce adrenergic stimulation of the heart, additional antiarrhythmic therapy when appropriate, and, in selected patients, an implantable cardioverter-defibrillator. But management extends beyond medications and devices. Exercise assessment, ongoing rhythm evaluation and individualized counseling remain important. For young patients, these discussions also involve school, sports, physical activity, family life and the understandable desire to live as normally as possible while managing a potentially serious inherited condition. The goal is not simply to treat an abnormal rhythm. It is to reduce risk while helping young people and their families understand the condition and continue living as fully and safely as possible.

Looking beyond the first patient

Physical activity has enormous cardiovascular, psychological, and social benefits, and sudden cardiac arrest in young athletes is uncommon. The lesson from this family is not that children should fear participating in sports. The lesson is that certain warning signs deserve attention. A child who collapses during exercise warrants careful evaluation. Do not automatically dismiss palpitations, dizziness, or seizure-like activity associated with strenuous exercise. A family history of unexplained sudden death should prompt additional questions. And a normal resting ECG does not necessarily end the evaluation when the clinical history remains concerning.

One teenage athlete experienced a cardiac arrest during a track event and survived because people around her acted. Her evaluation identified an inherited rhythm disorder. Screening then identified the same condition in her mother and two siblings. Years later, screening identified the familial condition in her daughter—before a cardiac arrest ever occurred. What began as an effort to save one young athlete ultimately became an opportunity to identify cardiovascular risk across three generations of one family. When an inherited rhythm disorder is identified in one child, the diagnosis may be only the beginning. The greater opportunity is to identify the next person at risk before the first life-threatening event ever occurs.

References

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2. Stiles MK, Wilde AAM, Abrams DJ, et al. 2020 APHRS/HRS expert consensus statement on the investigation of decedents with sudden unexplained death and patients with sudden cardiac arrest, and of their families. Heart Rhythm. 2021;18(1):e1–e50.

3. Wilde AAM, Semsarian C, Márquez MF, et al. European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on the state of genetic testing for cardiac diseases. Europace. 2022;24(8):1307–1367.

4. Lampert R, Chung EH, Ackerman MJ, et al. 2024 HRS expert consensus statement on arrhythmias in the athlete: Evaluation, treatment, and return to play. Heart Rhythm. 2024.

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