Wolf-Parkinson-White (WPW) OR Pre-excitation syndrome:

Wolf-Parkinson-White (WPW)

                                  Notice short PR interval and gradual upstroke of QRS complex

It's the premature excitation of the ventricular muscle before the normal conduction pathway delivers the normal electrical impulse due to the presence of an accessory bundle between Atria and Ventricle.

ECG would show:

1- Short PR interval

2- Wide QRS complex with an initial slow upstroke (called DELTA wave) before QRS complex

Management:

1- If the patient is clinically stable: use Procainamide, the use of B blockers or calcium channel blockers are absolutely contraindicated, because they may lead to over-riding of the bundle of Kent which may predispose to SVTs and VTs.

2- If the patient is Unstable: Electric cardio-version.

3- Ablation of the accessory bundle is the Definitive treatment.