short PR interval, less than 3 small squares (120 ms) slurred upstroke to the QRS indicating pre-excitation (delta wave) broad QRS secondary ST and T wave changes
Localising the accessory pathway An accessory pathway, bundle of Kent, exists between atria and ventricles and causes early depolarisation of the ventricle. The location of the pathway may be deduced as follows:-
LOCATION V1 V2 QRS axis
left posteroseptal (type A) +ve +ve left right lateral (type B) -ve -ve left left lateral (type C) +ve +ve inferior (90 degrees) right posteroseptal -ve -ve left anteroseptal -ve -ve normal
Thank you to Michael Bosshart for providing his recording.