This 78-year-old woman with a long-standing history of coronary artery disease is admitted to the cardiology ward for treatment of congestive heart failure:

• Sinus rhythm with sinus arrhythmia and premature atrial beats – Ventricular rate 64/min
• AV dissociation due to a competing junctional rhythm
• Rightward axis
• Non-specific intra-ventricular conduction block 
• T wave abnormality, consider inferior and anterolateral ischemia

Comment: Beats labeled “J” are junctional escapes whereas others are conducted beats.  Slowing of the sinus node forces the junction to fire and causes AV dissociation.  P-waves that happen to come relatively soon after a QRS complex are conducted with a long AV interval because firing of the junction causes AV node refractoriness.