Type 2 antiarrhythmics are which general category?

Type 2 antiarrhythmics are which general category?

• A. Beta blockers
• B. Sodium channel blockers
• C. Calcium channel blockers
• D. Potassium channel blockers

Answer: (A)

Type 2 antiarrhythmics are beta-adrenergic blockers. They work by blocking beta receptors in the heart, which reduces sympathetic stimulation. This lowers the slope of automaticity in the SA node and slows conduction through the AV node, leading to a slower heart rate and slower AV conduction—useful for controlling tachyarrhythmias with rapid ventricular response. This differs from the other classes: sodium channel blockers (Type I) affect depolarization in atrial/ventricular tissue; calcium channel blockers (Type IV) mainly slow nodal conduction by inhibiting L-type calcium channels; potassium channel blockers (Type III) prolong repolarization and the QT interval. Examples of Type II agents include propranolol, metoprolol, and esmolol.

Type 2 antiarrhythmics are beta-adrenergic blockers. They work by blocking beta receptors in the heart, which reduces sympathetic stimulation. This lowers the slope of automaticity in the SA node and slows conduction through the AV node, leading to a slower heart rate and slower AV conduction—useful for controlling tachyarrhythmias with rapid ventricular response.

This differs from the other classes: sodium channel blockers (Type I) affect depolarization in atrial/ventricular tissue; calcium channel blockers (Type IV) mainly slow nodal conduction by inhibiting L-type calcium channels; potassium channel blockers (Type III) prolong repolarization and the QT interval. Examples of Type II agents include propranolol, metoprolol, and esmolol.