Delta waves in ECG are characteristic of

(A) Wolf Parkinson White syndrome# DELTA WAVES are quite rare and represent a slurring of the QRS complex associated with Wolff-Parkinson-White syndrome. This may lead to tachycardias, and should be evaluated. Intermittent delta waves are certainly possible and often imply that the accessory pathway does not conduct very rapidly. This situation is relatively rare.> Wolff-Parkinson-White Preexcitation> Although not a true IVCD, this condition causes widening of QRS complex and, therefore, deserves to be considered here QRS complex represents a fusion between two ventricular activation fronts:> Early ventricular activation in region of the accessory AV pathway (Bundle of Kent)> Ventricular activation through the normal AV junction, bundle branch system ECG criteria include all of the following: Short PR interval (<0.12s) Initial slurring of QRS complex (delta wave) representing early ventricular activation through normal ventricular muscle in region of the accessory pathway Prolonged QRS duration (usually >0.10s) Secondary ST-T changes due to the altered ventricular activation sequence