PSVT patient develop CHB post radiofrequency ablation

A 81 yr/male was admitted to JIPMER hospital, Pondicherry, India with chief complaints of palpitation on and off since last 4 years. Patient was a known case of diabetes mellitus since last 4 yr and was on medical management.  Patient ECG done which was suggestive of Paroxysmal supraventricular tachycardia.

ECG of the patient (Click on the image to enlarge it)

ECG is showing narrow QRS, regular tachycardia at rate around 188 beats per minute, clearly visible P wave were not seen, few doubtful P wave merged into QRS complex seen in lead V1??Pseudo R wave , no other ST-T segment changes seen, so the ecg is suggestive of narrow complex tachycardia differential diagnosis being AVNRT most likely.
Patient underwent radiofrequency ablation for the PSVT. Following ablation ECG of the patient suggestive of high grade block.

ECG 2 

ECG is showing sinus bradycardia at rate 54 beats per minute, PR interval around 240 msec, QT interval 400 msec, QTc 380 msec, so pre-excitation seen, No ST-T wave changes seen.


                               ECG 3 suggestive of Complete heart block(Click on image to enlarge it)

 ECG is suggestive of heart rate around 60 beats per minute, there is complete AV dissociation, there is no consistent relationship between P wave and QRS complex, QRS complex of narrow in morphology, atrial rate around 100 beats per minute so the ECG is suggestive of  Complete heart block.

Patient underwent successful Pacemaker ablation and was discharged in stable condition.

Thank you.