Calcium Channel Blockers With Antiarrhythmic Properties

Understanding Non-Dihydropyridine Calcium Channel Blockers

Non-dihydropyridine calcium channel blockers are known for their antiarrhythmic effects and are commonly used in the management of various heart rhythm disorders. The primary medications in this category include diltiazem and verapamil. These drugs work by influencing the electrical activity in cardiac tissues, particularly in the sinoatrial and atrioventricular nodes.

Diltiazem: Managing Supraventricular Arrhythmias

Diltiazem effectively reduces the automaticity and conduction velocity of the sinoatrial node and atrioventricular node. This mechanism makes it particularly useful in treating supraventricular tachyarrhythmias such as atrial fibrillation and atrial flutter. It helps control ventricular rate and restore normal heart rhythm in patients experiencing these conditions.

Verapamil: Controlling Heart Rate and Preventing Arrhythmias

When taken orally, verapamil is effective in managing ventricular response in patients with atrial fibrillation or atrial flutter. It also plays a key role in preventing episodes of paroxysmal supraventricular tachycardia (PSVT). By slowing down the conduction through the atrioventricular node, verapamil helps maintain a stable heart rhythm and reduces the frequency of sudden arrhythmic events.

Intravenous Use for Acute Arrhythmia Management

Intravenous administration of these calcium channel blockers is often used in emergency settings. Diltiazem and verapamil can effectively convert PSVT and certain types of ventricular tachycardia back to normal sinus rhythm. They are also valuable in controlling rapid ventricular rates during atrial fibrillation or flutter, providing rapid relief and stabilizing the patient's condition.

Additional Therapeutic Benefits

Beyond their antiarrhythmic properties, these medications are also used to treat angina pectoris by reducing myocardial oxygen demand and improving blood flow to the heart. Additionally, they have shown benefits in managing hypertrophic cardiomyopathy, where they help reduce left ventricular outflow tract obstruction and improve symptoms such as shortness of breath and chest discomfort.