# Initiation of a Wide QRS Complex Tachycardia with Alternating Ventriculoatrial Interval: What Is the Mechanism?

## TL;DR

This paper discusses the mechanisms behind a specific type of heart rhythm disorder called wide QRS complex tachycardia.

## Contribution

The paper highlights how changes in intracardiac intervals can help diagnose the cause of this arrhythmia.

## Key findings

- Variations in intracardiac intervals can affect tachycardia cycle length.
- These changes can be diagnostic for different types of arrhythmias.

## Abstract

The differential diagnosis for wide complex tachycardia includes all causes of narrow complex tachycardia with bundle branch block, all causes of narrow complex tachycardia with antegrade pre-excitation, ventricular tachycardia, and antidromic and other pre-excited reciprocating tachycardias. The variation in a specific intracardiac interval that causes a subsequent change in the tachycardia cycle length or another intracardiac interval can be diagnostic in these arrhythmias.