In ACS, which scenario is a contraindication to beta-blocker therapy?

• A. Asymptomatic atrial fibrillation
• B. Cardiogenic shock
• C. Hypertension with tachycardia
• D. Normal blood pressure with tachycardia

Answer: (B)

In ACS, beta-blockers reduce myocardial oxygen demand by lowering heart rate, contractility, and blood pressure, which helps limit infarct size and improves survival in stable patients. The major contraindication is cardiogenic shock, because the heart already fails to maintain adequate output; adding a beta-blocker further depresses contractility and can precipitate or worsen life-threatening hypotension and poor organ perfusion. In a scenario with cardiogenic shock, the risk of further hemodynamic collapse outweighs any potential benefit.

The other situations described do not by themselves disqualify beta-blocker therapy. Asymptomatic atrial fibrillation can often benefit from rate control, hypertension with tachycardia is a common indication for beta-blockade to reduce myocardial workload, and tachycardia with normal blood pressure may be managed once the patient is stabilized. The key is recognizing when shock or significant hypotension is present, which makes beta-blockade unsafe.