# The missing P waves in wide QRS tachycardia

## TL;DR

A patient with a fast heart rate was initially thought to have a serious heart condition but was later correctly diagnosed and treated with a less severe condition.

## Contribution

This case highlights the importance of accurate diagnosis in wide QRS tachycardia using electrophysiological studies.

## Key findings

- Initial diagnosis of ventricular tachycardia was incorrect.
- Electrophysiological study revealed atrioventricular nodal reentrant tachycardia.
- Successful treatment with radiofrequency ablation resolved the tachycardia.

## Abstract

A 57-year-old male patient presented with paroxysmal palpitations for 2 years. The patient’s blood pressure was 120/76 mmHg; his heart rate was 149 beats/min. The presenting electrocardiogram showed a wide QRS complex tachycardia with an irregular rhythm. The RR intervals were irregular, and there were more complex QRS waves than P waves. The patient was first diagnosed with ventricular tachycardia. The ECG during sinus rhythm revealed a complete right bundle-branch block. The patient underwent an invasive electrophysiological study and was then diagnosed with atrioventricular nodal reentrant tachycardia (AVNRT). Following successful slow pathway radiofrequency ablation (located at the anterior part of the coronary sinus ostium), tachycardia was no longer inducible.