What Are Causes of Sudden Cardiac Death?

Patient Presentation
An 18-year-old female came to clinic for a pre-college physical examination. She had been a good athlete with only minor sports injuries. She was well but said, “I don’t know if you heard about my cousin, but he was the one who died suddenly after running earlier this summer. They think it was his heart.” The physician answered that he had heard because of the news stories and because the cousin was a local celebrity as he had been the state champion in the 1600-meter run. He expressed his condolences and took a more detailed history including that the patient had had no episodes of fainting, palpitations, dizziness or similar episodes. She emphatically denied any drug use, medically or recreationally. The cousin was the maternal uncle’s son, and the surviving parents and siblings were in the process of being medically evaluated for a possible genetic heart condition. The patient’s mother was well with no cardiac symptoms. The family history was negative for other sudden death, early deaths, or spontaneous abortions. There was stroke, diabetes and heart attacks on both sides of the family in people aged 60-80s. There had been another distant cousin on the paternal side of the family who died in a car accident. The review of systems was negative.

The pertinent physical exam showed a healthy appearing female with normal vital signs, with a weight 50% and height 75%.
Her heart had a normal S1, S2 without murmurs. There was no carotid or abdominal bruit. Methods to look for hyperflexibility were negative and her arm span was within 1 cm of her height. The diagnosis of a healthy female was made. The patient and her mother discussed with the physician that there was a potential increased risk of sudden death and that it potentially needed to be evaluated. The evaluation should be mainly guided based upon the results of the cousin’s families’ evaluation, but that normal laboratory testing for cholesterol, lipids, and glucose should be done anyways. The physician also said that he would talk with a cardiologist about further testing such as a Holter monitor, an echocardiogram, and possibly other genetic testing. Both the patient and mother agreed to wait for more information, particularly since the cousin’s family had been disclosing information to the rest of the family as it became available. The patient’s clinical course over the next year found that she was physically doing well. The cousin’s family’s evaluation found the cousin’s brother to have hypertropic cardiomyopathy. After a case review the cardiologist and did not recommend further evaluation for the patient.

Sudden death of a young person is a tragic event for the family and community no matter the cause. Healthy-appearing, young persons who suddenly die while engaging in athletic pursuits strikes as particularly catastrophic. Screening potential student athletes for possible cardiac problems is recommended using a variety of history and physical examination criteria. See To Learn More below. There are strong opinions that these guidelines do not go far enough and more modalities such as electrocardiograms and/or echocardiograms should be used.

Evaluation of surviving family members where a documented sudden cardiac death occurs is usually individualized and usually includes a history and physical examination, and an electrocardiogram. Other tests may include an echocardiogram treadmill, electrophysioloical studies and various genetic studies.

Learning Point
Sudden death can be caused by many different entities but all lead to a hypoventilation, hypoxia and/or cardiac arrhythmia which leads to death. Depending on the age and circumstances surrounding the death, a postmortem evaluation, death scene investigation, and social service or law enforcement interviews may be part of the determination of cause of death. Particularly in cases of young children, potential child abuse and SIDS require an extensive evaluation process to exclude other possibilities.

Some causes of sudden death include:

  • Allergic
    • Anaphylaxis
  • Cardiac – see below
  • Drug
    • Alcohol
    • Cocaine
    • Inhalant
    • Polypharmacy
  • Endocrine
    • Congenital adrenal hyperplasia
    • Diabetes
    • McCune Albright syndrome
  • Electrolyte abnormalities
  • Hematologic
    • Sickle cell anemia and trait
  • Genetic
    • Fabry
    • Hunter
    • Hurler
    • Marfan
  • Genitourinary
    • Pregnancy
    • Hypertension
  • Metabolic
    • Malignant hyperthermia
    • Rhabdomyolysis
  • Neurological
    • Brain stem injury
    • Prematurity with immature respiratory control
    • Seizure
    • Stroke
  • Pulmonary
    • Aspiration
    • Asthma
    • Foreign body
    • Pulmonary embolism
    • Prematurity – respiratory distress syndrome
  • Toxin
    • Carbon monoxide poisoning
    • Snake bite
    • Plants
  • Trauma/Accident
    • Blunt trauma
    • Child abuse – shaken baby
    • Drowning
    • Electrocution
    • Homicide/Suicide
    • Hypo or hyperthermia
    • Ingestion
    • Suffocation
  • Other
    • Obesity, morbid
    • Sepsis
    • SIDS
    • SADS – sudden adult death syndrome

Causes of sudden cardiac death in children and adolescents includes:

  • Aortic dissection/rupture – Marfan’s syndrome
  • **Cardiomyopathy including hypertrophic, dilated, arrhythmogenic right ventricular dysplasia, etc.
  • Congenital heart disease – aortic stenosis, transposition of great arteries, atrioventricular septal defect, etc.
  • Coronary artery anomalies
  • Coronary artery disease
  • **Myocarditis
  • Valve disease
  • **Ion channelopathies – congenital long-QT syndrome, Brugada syndrome, etc.
  • Commotio cordis

** = most common

Questions for Further Discussion
1. What cardiac history and physical examination findings are recommended for prescreening of student athletes?
2. What are the pros/cons of adding an electrocardiogram and/or echocardiogram for prescreening of student athletes?
3. What are causes of chest pain in children?
4. What are causes of fainting in children?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Cardiac Arrest and Cardiomyopathy.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

Maron BJ, Thompson PD, Ackerman MJ, et al.. American Heart Association Council on Nutrition, Physical Activity, and Metabolism. Recommendations and considerations related to preparticipation screening for cardiovascular abnormalities in competitive athletes: 2007 update: a scientific statement from the American Heart Association Council on Nutrition, Physical Activity, and Metabolism: endorsed by the American College of Cardiology Foundation. Circulation. 2007 Mar 27;115(12):1643-1655.

Ackerman MJ. State of postmortem genetic testing known as the cardiac channel molecular autopsy in the forensic evaluation of unexplained sudden cardiac death in the young. Pacing Clin Electrophysiol. 2009 Jul;32 Suppl 2:S86-9.

Ackerman MJ. Rowland T. Sudden unexpected death in young athletes: reconsidering “hypertrophic cardiomyopathy”. Pediatrics. 2009 Apr;123(4):1217-22.

Hershberger RE, Lindenfeld J, Mestroni L, Seidman CE, Taylor MR, Towbin JA; Heart Failure Society of America. Genetic evaluation of cardiomyopathy–a Heart Failure Society of America practice guideline. J Card Fail. 2009 Mar;15(2):83-97.

Devinsky O. Sudden, unexpected death in epilepsy. N Engl J Med. 2011 Nov 10;365(19):1801-11.

Kaltman JR, Thompson PD, Lantos J, et al. Screening for sudden cardiac death in the young: report from a national heart, lung, and blood institute working group. Circulation. 2011 May 3;123(17):1911-8.

Paterick TE, Jan MF, Seward JB, Tajik AJ. March Madness 2011: for whom the bell tolls? Am J Med. 2012 Mar;125(3):231-5.

Ilina MV, Kepron CA, Taylor GP, Perrin DG, Kantor PF, Somers GR. Undiagnosed heart disease leading to sudden unexpected death in childhood: a retrospective study. Pediatrics. 2011 Sep;128(3):e513-20.

Goldsmith JC, Bonham VL, Joiner CH, Kato GJ, Noonan AS, Steinberg MH. Framing the research agenda for sickle cell trait: building on the current understanding of clinical events and their potential implications. Am J Hematol. 2012 Mar;87(3):340-6.

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    5. Patients and their families are counseled and educated.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.

  • Interpersonal and Communication Skills
    17. A therapeutic and ethically sound relationship with patients is created and sustained.
    18. Using effective nonverbal, explanatory, questioning, and writing skills, the healthcare professional uses effective listening skills and elicits and provides information.
    19. The health professional works effectively with others as a member or leader of a health care team or other professional group.

  • Systems Based Practice
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.
    25. Quality patient care and assisting patients in dealing with system complexities is advocated.
    26. Partnering with health care managers and health care providers to assess, coordinate, and improve health care and how these activities can affect system performance are known.


    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital