ECG Features

• Regular rhythm with ventricular rate >100 beats/min
• Narrow QRS complexes unless aberrant conduction
• P waves buried in the QRS complex, immediately following a short RP interval (<90 ms) or long RP interval
• Note: ~90% of all supraventricular tachycardias associated with (1) AV nodal reentrant tachycardia (~60%) or (2) AV reentrant tachycardia (~30%)