Which test is required for all patients with new-onset heart failure or new-onset atrial fibrillation to evaluate an endocrine cause?

Which test is required for all patients with new-onset heart failure or new-onset atrial fibrillation to evaluate an endocrine cause?

• A. TSH level
• B. Lipid panel
• C. Troponin
• D. CBC

Answer: (A)

Thyroid dysfunction is a frequent, reversible cause of both heart failure and atrial fibrillation. Thyroid hormones affect heart rate, contractility, and overall cardiac metabolism, so excess thyroid hormone can trigger atrial fibrillation, while low thyroid function can contribute to heart failure symptoms. Because of this, screening for thyroid disease with a TSH level is the most appropriate initial test in patients with new-onset heart failure or new-onset atrial fibrillation. If the TSH is abnormal, measuring free T4 (and possibly T3) helps define the exact thyroid status and guide treatment. The other tests don’t target endocrine causes: lipid panels assess lipid risk factors for atherosclerosis, troponin detects acute myocardial injury, and CBC looks for anemia or infection.

Thyroid dysfunction is a frequent, reversible cause of both heart failure and atrial fibrillation. Thyroid hormones affect heart rate, contractility, and overall cardiac metabolism, so excess thyroid hormone can trigger atrial fibrillation, while low thyroid function can contribute to heart failure symptoms. Because of this, screening for thyroid disease with a TSH level is the most appropriate initial test in patients with new-onset heart failure or new-onset atrial fibrillation. If the TSH is abnormal, measuring free T4 (and possibly T3) helps define the exact thyroid status and guide treatment.

The other tests don’t target endocrine causes: lipid panels assess lipid risk factors for atherosclerosis, troponin detects acute myocardial injury, and CBC looks for anemia or infection.