WPW--Wolf-Parkinson-White Syndrome

• Wolf-Parkinson-White Syndrome (WPW) is a reentrant rhythm disturbance that can degenerate into malignant wide complex tachydysrhythmias, which can be life-threatening.
• The likelihood of WPW with atrial fibrillation degenerating into ventricular fibrillation is exceedingly rare at 0.1%.
• Nodal agents, such as beta blockers, calcium channel blockers and adenosine, should not be used in wide complex tachycardias or atrial fibrillation for therapeutic or diagnostic purposes if WPW is suspected.
• Preferred agents for wide complex tachycardias where WPW is suspected are class 1A (e.g., procainamide) or class 3 (e.g., amiodarone) agents. ACLS 2005 guidelines emphasize the use of amiodarone in patients with depressed cardiac function (EF<40%).
• Electrolyte disturbances (e.g., hypokalemia, hyperkalemia and metabolic acidosis) can increase the risk for arrhythmia and Sudden Cardiac Death.