Interpretation
- Regular Narrow Complex Tachycardia at a rate of 239/min
- Inverted P waves after the QRS in Lead II (called pseudo-s waves)
- Upright P waves are also seen after the QRS in Lead V1 (called pseudo-r waves)
The pseudo-R and pseudo-S waves are caused by retrograde transmision of atrial depolarisation from the AV node, and are seen in AVNRT, so this tachycardia is Slow-Fast AVNRT (Common AVNRT).