A slurred QRS upstroke, ... the QRS complex 0.09, and PJ 0.21. Slurred onset of QRS complex producing a delta wave is best recorded in Lead V1 and also seen in Lead aVL and across the precordium.

Both QRS complexes have a slurred upstroke (↑,^), making the base of the QRS complex wider than the peak. The slurred upstroke is due to a delta wave; along with the short PR interval, this is a ...

Furthermore, these QRS complexes have a slurred upstroke (indicated by a right arrow [→] in Figure 2), especially obvious in leads I, aVL and V4-V6. Two narrow QRS complexes ...