Verapamil

Verapamil is a Non-Dihydropyridine Calcium Channel Blocker (Non-DHP CCB).

It primarily affects cardiac tissue and AV nodal conduction.

Used in:

• Dysrhythmias (rate control)
• Stable Angina
• Hypertension

→ Calcium Channel Blockers

Verapamil blocks L-type calcium channels in:

• SA node
• AV node
• Myocardial tissue
• Vascular smooth muscle (less than DHPs)

Effects:

• ↓ Heart rate
• ↓ AV nodal conduction
• ↓ Contractility
• Mild ↓ Afterload

Primary action = cardiac.

Verapamil slows:

• Phase 0 depolarization in nodal tissue
• AV nodal conduction velocity

Prolongs:

• PR interval

Used for:

• Rate control in atrial fibrillation
• SVT termination (AV nodal dependent)

• ↓ Heart rate
• ↓ Contractility
• Mild vasodilation

Reduces myocardial oxygen demand by:

• Lowering heart rate
• Lowering contractility

Arrhythmias:

• Rate control in AF
• SVT (AV nodal reentry)

Angina:

• Alternative to Beta-Blockers
• Useful when beta-blockers contraindicated

Hypertension:

• Less commonly first-line
• Useful in select patients

Common:

• Bradycardia
• Hypotension
• Constipation (classic)
• Peripheral edema (less than DHPs)

Serious:

• AV block
• Worsening heart failure

Avoid in:

• Heart Failure with Reduced EF
• High-grade AV block
• Severe bradycardia

Avoid combination with:

• Beta-Blockers

(risk of heart block)

Compared to:

• Amlodipine

Verapamil:

• Slows AV node
• Reduces heart rate
• Stronger cardiac effects

Amlodipine:

• Primarily vasodilator
• Minimal AV node effect

• Non-DHP CCB
• Slows AV node
• Decreases contractility
• Prolongs PR interval
• Causes constipation
• Avoid in HFrEF
• Avoid with beta-blockers

• Calcium Channel Blockers
• Non-Dihydropyridines
• Diltiazem
• Beta-Blockers
• Dysrhythmias
• Heart Failure