# A Wide QRS Complex Tachycardia with Variation of Ventriculoatrial Interval: What is the Mechanism?

## TL;DR

This paper discusses the mechanism behind a type of heart rhythm disorder with a wide QRS complex and changing ventriculoatrial interval.

## Contribution

The paper highlights how variation in a specific intracardiac interval can aid in diagnosing complex arrhythmias.

## Key findings

- Variation in intracardiac intervals can change tachycardia cycle length.
- Such changes can help distinguish between different types of arrhythmias.
- Intracardiac interval analysis is a diagnostic tool for wide complex tachycardia.

## 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.