A 40-year-old man had exertional syncope; which history finding is most likely to determine the diagnosis?

A 40-year-old man had exertional syncope; which history finding is most likely to determine the diagnosis?

• A. Recent viral illness
• B. Low blood pressure at rest
• C. No family history of cardiac disease
• D. Family history of sudden cardiac death

Answer: (D)

Exertional syncope in a middle-aged adult often points to a structural or electrical heart disease that can be inherited. The most informative history finding is a family history of sudden cardiac death, because many conditions that cause exercise-induced syncope—such as hypertrophic cardiomyopathy or inherited arrhythmia syndromes—have a strong familial pattern. When relatives die suddenly, it raises the likelihood of an occult cardiomyopathy or channelopathy and steers the evaluation toward targeted tests like ECG and echocardiography, with possible genetic testing. In contrast, a recent viral illness suggests myocarditis but is less determinative, low resting blood pressure indicates baseline hypotension without explaining exertional syncope, and no family history lowers suspicion for inherited disease, though it doesn’t rule it out.

Exertional syncope in a middle-aged adult often points to a structural or electrical heart disease that can be inherited. The most informative history finding is a family history of sudden cardiac death, because many conditions that cause exercise-induced syncope—such as hypertrophic cardiomyopathy or inherited arrhythmia syndromes—have a strong familial pattern. When relatives die suddenly, it raises the likelihood of an occult cardiomyopathy or channelopathy and steers the evaluation toward targeted tests like ECG and echocardiography, with possible genetic testing. In contrast, a recent viral illness suggests myocarditis but is less determinative, low resting blood pressure indicates baseline hypotension without explaining exertional syncope, and no family history lowers suspicion for inherited disease, though it doesn’t rule it out.