The drug of choice in patient with Parkinson-White syndrome with fibrillation is –
Parkinson-White syndrome is another name for WPW (Wolff-Parkinson-White) syndrome. That's a condition where there's an accessory pathway causing pre-excitation on the ECG. Fibrillation in this context would likely be atrial fibrillation, which can be dangerous because the accessory pathway can conduct impulses rapidly, leading to ventricular fibrillation or very fast heart rates.
The question is asking for the drug of choice. I remember that in WPW with atrial fibrillation, certain antiarrhythmics are contraindicated because they can accelerate conduction through the accessory pathway. Verapamil and digoxin are big no-nos because they can increase the risk of ventricular fibrillation. So the correct drugs would be those that block the AV node but not the accessory pathway. Procainamide and ibutilide are options. Also, synchronized cardioversion might be necessary if the patient is hemodynamically unstable.
Looking at the options, the correct answer is probably procainamide or ibutilide. Let me check the standard guidelines. AHA/ACC guidelines suggest procainamide as a first-line for acute management of atrial fibrillation with WPW. So the correct answer is procainamide. The wrong options would include drugs like adenosine, which is not effective in WPW because it blocks the AV node but not the accessory pathway, and beta-blockers might be used but not first-line. Amiodarone is sometimes used but not first-line. So the incorrect options would be A, B, C, D, but since the user didn't provide the options, I need to make sure the explanation is accurate regardless.
The core concept here is the management of atrial fibrillation in WPW syndrome. The key is avoiding AV nodal blockers because they can worsen the situation. The correct drug should block the accessory pathway. Procainamide is a class IA antiarrhythmic that does this. The clinical pearl would be to remember that in WPW with AF, avoid verapamil/digoxin and use procainamide or ibutilide. Also, cardioversion is preferred if unstable.
**Core Concept**
Wolff-Parkinson-White (WPW) syndrome involves an accessory atrioventricular (AV) pathway, increasing risk of rapid conduction during atrial fibrillation (AF). Drug selection in AF with WPW must avoid AV nodal blockers (e.g., verapamil, digoxin), as these may accelerate ventricular rate via the accessory pathway, risking ventricular fibrillation.
**Why the Correct Answer is Right**
Procainamide (a class IA antiarrhythmic) is the drug of choice for acute AF in WPW. It slows conduction in both the AV node and accessory pathway by blocking sodium channels, stabilizing cardiac membrane potential. This reduces risk of rapid ventricular response and prevents re-entry circuit perpetuation. Procainamide is preferred over other agents like amiodarone in stable patients due to its predictable effect on accessory pathway conduction.
**Why Each Wrong Option is Incorrect**
**Option A:** Adenosine blocks the AV node but not the accessory pathway, accelerating vent