Final answer:
The treatment for refractory SVT due to WPW involves antiarrhythmic medications like potassium channel blockers, catheter ablation, and potentially, the implantation of an artificial pacemaker or urgent cardioversion or defibrillation in severe cases.
Step-by-step explanation:
The treatment for refractory Supraventricular Tachycardia (SVT) due to Wolff-Parkinson-White (WPW) syndrome may involve several approaches. Initially, antiarrhythmic medications, such as potassium channel blockers like procainamide or amiodarone, can be used to manage the heart rhythm. These medications work by impeding the movement of potassium ions through voltage-gated K+ channels, therefore affecting the repolarization phase of the action potential, which can help restore normal heart rhythm.
In more severe cases, and when medication is not sufficiently effective, an individual may require a procedure called catheter ablation. This procedure targets and destroys the abnormal electrical pathways in the heart that are causing the arrhythmia. In urgent situations, controlled electric shocks in the form of cardioversion or defibrillation may also be employed to reset the heart's rhythm. For chronic cases that do not respond to less invasive treatments, the implantation of an artificial pacemaker can be considered to maintain a regular heart rate.