Natural Deaths: Practice Question

A 27-year-old woman with purging-type bulimia nervosa is found unresponsive at home. In the absence of evidence of trauma, intoxication, or another acute illness, which immediate mechanism is most likely to explain sudden death?

Fatal cardiac arrhythmia due to purging-associated hypokalemia (electrolyte disturbance)
Neoplasia
Volume loss
Hypoglycemia
Caloric or protein malnutrition

Show Answer and Explanations

Fatal cardiac arrhythmia due to purging-associated hypokalemia (electrolyte disturbance) — Correct answer

Correct. Recurrent self-induced vomiting and other purging behaviors can cause potassium and other electrolyte losses, often with hypochloremic metabolic alkalosis. Hypokalemia can alter cardiac electrical activity and precipitate QT abnormalities and potentially fatal ventricular arrhythmias. In this causal sequence, bulimia nervosa is the underlying disorder; the electrolyte disturbance is the immediate pathophysiologic mechanism, and fatal arrhythmia is the terminal event.

Neoplasia

Incorrect. Neoplasia is not supported by the clinical scenario and is not a characteristic acute mechanism of sudden death associated with purging-type bulimia nervosa.

Volume loss

Incorrect as the best answer. Volume depletion can coexist with vomiting, laxative misuse, or diuretic misuse and may worsen renal perfusion and electrolyte abnormalities, but it is less specific than hypokalemia-related electrical instability as the classic sudden-death mechanism in purging-type bulimia nervosa.

Hypoglycemia

Incorrect as the best answer. Hypoglycemia may occur with inadequate intake, but it is less characteristic than purging-associated hypokalemia and arrhythmia as the classic explanation for sudden death in this scenario.

Caloric or protein malnutrition

Incorrect as the best answer. Caloric or protein malnutrition can produce chronic medical complications in severe eating disorders, but it is not the classic immediate mechanism of sudden death from recurrent purging in bulimia nervosa.

Summary

Summary: In purging-type bulimia nervosa, recurrent vomiting and/or laxative or diuretic misuse can cause fluid, electrolyte, and acid-base disturbances. Potassium depletion, often with hypochloremic metabolic alkalosis, can produce cardiac electrical instability and fatal arrhythmias. Thus, the underlying disorder is bulimia nervosa, while electrolyte disturbance is the immediate pathophysiologic mechanism and arrhythmia is the terminal event. In forensic practice, this conclusion requires corroborating postmortem, toxicologic, and circumstantial evidence.

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