Which symptoms are typical of hyperthyroidism affecting the cardiovascular system, and how do anti-thyroid medications help?

• A. Tachycardia, palpitations, atrial fibrillation, systolic hypertension; weight loss; antithyroid medications reduce thyroid hormone production and alleviate tachycardia.
• B. Bradycardia and hypotension; no effect from antithyroid meds.
• C. Chest pain due to reduced thyroid hormones; antithyroid meds relieve pain.
• D. Edema and hyperkalemia; antithyroid meds increase hormone production.

Answer: (A)

Hyperthyroidism increases metabolic rate and adrenergic sensitivity, so the heart often runs faster and harder. This produces tachycardia, palpitations, and can lead to atrial fibrillation and a systolic-dominant hypertension pattern, with weight loss from the accelerated metabolism. Anti-thyroid medications work by reducing the synthesis of thyroid hormones, lowering circulating T3 and T4. With fewer hormones driving the heart, heart rate and contractility decrease, the risk of arrhythmias like atrial fibrillation diminishes, and symptoms such as palpitations and elevated systolic blood pressure improve. They don’t help with conditions typical of low thyroid hormone, like bradycardia or hypotension, and they don't cause edema or hyperkalemia or increase hormone production.