Interpretation
There are P waves intermittently present – the negative deflections in Leads II,III and AVF (arrows on image).
The ladder diagram provides the official solution. There is a Tachycardia at 140/min with retrograde (V-A) conduction.
Note the changing R-P intervals, consistent with Wenckebach prolongation, unit a “dropped P waves” occurs.
Conclusion: the rhythm is Ventricular Tachycardia with 4:3 Wenckebach V-A Conduction.
The Ventriculo-Atrial association proves that the ventricle is in command.