Drug of choice for maintenance therapy in PS VT is-
**Core Concept**
PSVT (Paroxysmal Supraventricular Tachycardia) is a type of cardiac arrhythmia characterized by a sudden, brief episode of rapid heart rate originating from the atria. Maintenance therapy aims to prevent recurrence of these episodes.
**Why the Correct Answer is Right**
The drug of choice for maintenance therapy in PSVT is typically a beta-blocker, specifically metoprolol or propranolol. These medications work by blocking the effects of catecholamines on the heart, thereby reducing the frequency and duration of PSVT episodes. Beta-blockers also slow the heart rate and reduce the force of contraction, which can help to prevent the initiation of PSVT.
**Why Each Wrong Option is Incorrect**
**Option A:** Digoxin is not typically used for maintenance therapy in PSVT, as it can actually increase the risk of PSVT episodes in some patients.
**Option B:** Calcium channel blockers, such as verapamil, can be used to treat PSVT episodes but are not the first-line choice for maintenance therapy.
**Option C:** Amiodarone is a powerful antiarrhythmic medication, but it is usually reserved for more severe or resistant cases of PSVT.
**Clinical Pearl / High-Yield Fact**
Beta-blockers are a good initial choice for maintenance therapy in PSVT because they are effective, well-tolerated, and can be easily titrated to achieve the desired effect.
**Correct Answer:** C. Amiodarone