Note the premature ventricular contraction (PVC) that triggers the AVNRT in this ECG. If a premature atrial contraction (PAC) or premature ventricular contraction (PVC) occurs at the right time ...

This is a narrow-complex QRS rhythm which is quite fast. Looking closely at the last part of the QRS complex in leads V1 and V2, P waves can be seen. This is considered a "short RP tachycardia ...