Question:medium
A 65-year-old patient with history of atrial flutter is being considered for long-term prophylaxis to prevent recurrence. The cardiologist decides to start a calcium channel blocker for rate control and prevention of rapid ventricular response. Which calcium channel blocker is most appropriate?
A 65-year-old patient with history of atrial flutter is being considered for long-term prophylaxis to prevent recurrence. The cardiologist decides to start a calcium channel blocker for rate control and prevention of rapid ventricular response. Which calcium channel blocker is most appropriate?
Show Hint
For AF or atrial flutter rate control, use diltiazem or verapamil, not amlodipine.
Updated On: May 14, 2026
- Amlodipine
- Nifedipine
- Diltiazem
- Felodipine
Show Solution
The Correct Option is C
Solution and Explanation
Step 1: Understanding the Question:
The question asks for the selection of a Calcium Channel Blocker (CCB) specifically used for "rate control" in a supraventricular arrhythmia (Atrial Flutter).
Step 2: Detailed Explanation:
Classification of CCBs:
- Dihydropyridines (DHP): Amlodipine, Nifedipine, Felodipine. These primarily cause vasodilation and have little to no effect on the heart's conduction system.
- Non-Dihydropyridines (Non-DHP): Diltiazem and Verapamil. These act on both the vessels and the heart.
Mechanism of Action: Non-DHP CCBs like Diltiazem work by blocking L-type calcium channels in the Sinoatrial (SA) and Atrioventricular (AV) nodes. This slows AV conduction and prolongs the refractory period.
Clinical Use in Flutter/Fibrillation: For Atrial Flutter, the goal of a CCB is to prevent a 1:1 or 2:1 conduction of rapid atrial impulses to the ventricles. By slowing the AV node, Diltiazem maintains a safe heart rate (rate control).
- DHP CCBs (A, B, D) are ineffective for arrhythmias and can cause reflex tachycardia, which might worsen the situation.
Prophylaxis: Diltiazem is often used for long-term oral rate control in patients who cannot tolerate beta-blockers.
Step 3: Final Answer:
Diltiazem is the correct choice as it is a Non-DHP CCB with significant AV nodal blocking properties.
The question asks for the selection of a Calcium Channel Blocker (CCB) specifically used for "rate control" in a supraventricular arrhythmia (Atrial Flutter).
Step 2: Detailed Explanation:
Classification of CCBs:
- Dihydropyridines (DHP): Amlodipine, Nifedipine, Felodipine. These primarily cause vasodilation and have little to no effect on the heart's conduction system.
- Non-Dihydropyridines (Non-DHP): Diltiazem and Verapamil. These act on both the vessels and the heart.
Mechanism of Action: Non-DHP CCBs like Diltiazem work by blocking L-type calcium channels in the Sinoatrial (SA) and Atrioventricular (AV) nodes. This slows AV conduction and prolongs the refractory period.
Clinical Use in Flutter/Fibrillation: For Atrial Flutter, the goal of a CCB is to prevent a 1:1 or 2:1 conduction of rapid atrial impulses to the ventricles. By slowing the AV node, Diltiazem maintains a safe heart rate (rate control).
- DHP CCBs (A, B, D) are ineffective for arrhythmias and can cause reflex tachycardia, which might worsen the situation.
Prophylaxis: Diltiazem is often used for long-term oral rate control in patients who cannot tolerate beta-blockers.
Step 3: Final Answer:
Diltiazem is the correct choice as it is a Non-DHP CCB with significant AV nodal blocking properties.
Was this answer helpful?
0
