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

It has both cardiac and vascular effects and is commonly used for rate control and angina.

Used in:

• Dysrhythmias
• Stable Angina
• Hypertension

→ Calcium Channel Blockers

Diltiazem blocks L-type calcium channels in:

• SA node
• AV node
• Myocardial tissue
• Vascular smooth muscle

Effects:

• ↓ Heart rate
• ↓ AV nodal conduction
• ↓ Contractility (mild-to-moderate)
• ↓ Afterload

Compared to Verapamil:

• Slightly less negative inotropy
• More vasodilatory effect

Diltiazem slows:

• AV nodal conduction
• Nodal depolarization

Prolongs:

• PR interval

Used for:

• Rate control in atrial fibrillation
• SVT management

• ↓ Heart rate
• ↓ Contractility (less than verapamil)
• ↓ Systemic vascular resistance

Improves angina by:

• Reducing myocardial oxygen demand
• Mild coronary vasodilation

Arrhythmias:

• Rate control in AF
• SVT

Angina:

• Alternative to Beta-Blockers
• Useful in vasospastic angina

Hypertension:

• Secondary option
• Particularly useful when rate control also desired

Common:

• Bradycardia
• Hypotension
• Peripheral edema
• Fatigue

Serious:

• AV block
• Worsening heart failure

Less constipation than Verapamil.

Avoid in:

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

Use caution with:

• Beta-Blockers (risk of heart block)

Verapamil:

• Stronger cardiac suppression
• More constipation

Amlodipine:

• Pure vasodilator
• Minimal AV nodal effect

Diltiazem:

• Balanced cardiac + vascular effects
• Commonly used for AF rate control

• Non-DHP CCB
• Slows AV node
• Moderate negative inotropy
• Useful in AF with hypertension
• Avoid in HFrEF
• Avoid combining with beta-blockers

• Calcium Channel Blockers
• Non-Dihydropyridines
• Verapamil
• Amlodipine
• Dysrhythmias
• Heart Failure