20-year old patient with sudden onset of palpitations. What does the ECG show?
Describe and interpret this ECG
ECG ANSWER and INTERPRETATION
When you see a regular narrow complex tachycardia at 150 bpm, you should think of four main diagnoses:
- Atrial flutter with 2:1 block (especially in elderly, IHD, CCF)
- AV-nodal reentry tachycardia (“SVT”)
- Orthodromic AV reentry tachycardia in WPW
- Sinus tachycardia — should see P waves but may be hidden in the T waves (e.g. with concurrent 1st degree AV block). There should also be some HR variability compared to the other 3 rhythms.
The next step is a therapeutic trial of vagal maneouvres and/or adenosine… (see Quiz ECG 017).