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Sudden natural death — causes by age and what the autopsy examines
Sudden natural death is unexpected death from disease; in adults it results mainly from coronary artery disease, and in the young from cardiomyopathies, coronary anomalies and inherited arrhythmias — so when the heart looks normal, the autopsy continues to genetic testing (molecular autopsy) and family screening.
Why it matters in the exam
The exam gives a description of sudden death and an autopsy finding and asks for the cause or the next step. In adults over 35 the common cause is coronary atherosclerosis, sometimes with fresh thrombus or an old scar, and even without a visible infarct — because in the first hours of ischaemia there is no gross change and death is caused by arrhythmia. Other causes: left ventricular hypertrophy from hypertension, aortic dissection, pulmonary embolism, intracerebral haemorrhage, asthma and epilepsy (SUDEP).
In the young the leading causes are hypertrophic cardiomyopathy (with myocyte disarray), arrhythmogenic right ventricular cardiomyopathy (replacement of muscle by fat and fibrosis), myocarditis, anomalous origin of a coronary artery running between the aorta and pulmonary artery, and coronary aneurysms after childhood Kawasaki disease. Anabolic steroid use, for example in an athlete with acne, baldness, small testes and an enlarged heart, is linked to hypertrophy and sudden death.
When the heart is structurally normal and toxicology is negative, inherited arrhythmias — long QT, Brugada, CPVT — must be considered, and blood or tissue kept frozen for genetic testing. The finding requires referral of first-degree relatives for cardiological assessment, because lives can be saved. A full cardiac examination includes weighing, measuring wall thickness, sectioning the coronary arteries at close intervals and histological sampling according to protocol.
Key points
- Adults: coronary atherosclerosis is the common cause.
- Young: cardiomyopathies, coronary anomalies and myocarditis.
- In the first hours of ischaemia there is no visible change.
- Normal heart: genetic testing and family screening.
- Anabolic steroids are linked to hypertrophy and sudden death.
Summary table
| Age group | Common cause | Autopsy finding | Further step |
|---|---|---|---|
| Over 35 | Coronary atherosclerosis | Stenosis or thrombus, scar; sometimes no visible infarct | Histology from several areas |
| Young | Hypertrophic cardiomyopathy | Wall thickening, myocyte disarray | Family screening |
| Young | Arrhythmogenic cardiomyopathy | Fat and fibrosis in the right ventricle | Family screening |
| Young | Anomalous coronary origin, aneurysm after Kawasaki | Abnormal course or aneurysm | Ask about childhood illness |
| Normal heart | Inherited arrhythmia | No structural finding | Genetic testing and family screening |
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Sources
- Association for European Cardiovascular Pathology: Guidelines for autopsy investigation of sudden cardiac death, 2017 update — Protocol, sampling and molecular autopsy
- ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death, 2022 — Investigation of unexplained sudden death and family screening
- Knight's Forensic Pathology, 4th edition (2016) — Sudden natural death
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.