Question

Calcium Channel Blockers are contraindicated in

• A. Acute Left Ventricular Failure
• B. Essential Hypertension
• C. Peripheral Vascular Disease
• D. Primary Pulmonary Hypertension

Hint:

Think about what a drug that weakens heart contraction would do to an already failing heart.

Answer 1

The Correct Option is A

Step 1: Start from the drug's core action.
Calcium channel blockers work by blocking calcium entry into muscle cells, which relaxes blood vessel walls and, for some members of this drug group, also weakens the force with which the heart muscle squeezes.

Step 2: Match this action against acute left ventricular failure.
An acutely failing left ventricle is already unable to pump adequately. Adding a drug that cuts contraction strength even further removes the little reserve the heart has left, risking a sudden drop in cardiac output and blood pressure. This makes the drug class unsafe in this setting.

Step 3: Go through the remaining choices one by one.
Essential hypertension is actually one of the main reasons these drugs are prescribed, since they lower blood pressure by relaxing vessels. Peripheral vascular disease benefits from the vessel widening effect of dihydropyridine agents rather than being harmed by it. Primary pulmonary hypertension patients who show a positive response on vasodilator testing are treated with high dose calcium channel blockers as first line therapy, so this is not an absolute contraindication.

Step 4: Settle on the answer.
Only the acutely failing heart is truly put at risk by the negative effect on contraction, making acute left ventricular failure the correct contraindication.