ECG interpretation

Question 1

What are the potential rhythms causing a narrow complex tachycardia?

Answer 1

1) Sinus tachy -p waves upright in lead 2 & inverted in avr and every qrs has a p wave
2) Atrial flutter - II, III avf show flutter waves - HR commonly 150bpm (2:1)
3) SVT - no visible p waves, fast rate