1. 19 yr old boy Palpitations on effort since several weeks Normal echo Comments from Chandrashekhar and Tahmeed

2. Analyse- Atrial tachycardia --rapid and irregular ​with clear isoelectric line between the P waves with varying AV conduction. Notching on T wave and additional P waves seen on many beats; DDx: PACs/short. Runs of AT. While this appears to be irregular automatic tachy from the high RA, we have no comparison with the sinus P waves. The biphasic P in III and the completely negative P in V1 suggest site of origin anteroinferior to the sinus node.

3. Intracardiacs- there is variation in the atrial activation sequence, suggesting MAT. However, the catheters could be unsteady, since the Ps looked similar in the previous ECG. There is no pause to suggest a sinus complex. 500 ms

4. Faster speed

5. During RF energy- now there is sinus rhythm to compare- note the mildy positive P in V1

6. RF site- RAO 30. Between high crista and base of RA appendage

7. RF site-LAO 40

8. After this- no arrhythmia Final Diagnosis? Irregular incessant automatic atrial tachycardia. Successful RF ablation Next day-ECG normal.