Dual 1:2 tachycardia: What is the mechanism?

Widening of the QRS complex during the wide complex tachycardia: What is the mechanism?

Tachycardia-induced tachycardia, or so-called double tachycardia, appears to be a relatively rare condition. This article is protected by copyright. All rights reserved.

Simultaneous narrow and wide QRS complex tachycardia: Misdiagnosis or Missed diagnosis?

Tachycardia-induced tachycardia, or so-called double tachycardia, appears to be a relatively rare condition. Regardless of the mechanism, this case illustrates the importance of assessing the response to multiple different pacing maneuvers in determining the mechanism of narrow and wide QRS complex tachycardias, rather than relying upon a single maneuver, even one that is believed to be diagnostic. This article is protected by copyright. All rights reserved.

Transient changes in QRS morphology during a narrow complex tachycardia: What is the mechanism?

The observation of electrograms and electrocardiograms recorded in sinus rhythm can offer important initial information about the mechanism of arrhythmia. Some patients may have both bundle branch aberrancy or a bystander pathway or multiple pathways, giving rise to varying degrees of QRS fusion. There is need to focus on any change in cycle length of the tachycardia and morphology of QRS during tachycardia. This article is protected by copyright. All rights reserved.

Transition from Two Wide to A Narrow QRS Complex Tachycardia: What is the mechanism of tachycardia and transition?

Spontaneous transition from one tachycardia to another tachycardia poses a challenge to the electrophysiologists and most likely occurs by multiple mechanisms. This article is protected by copyright. All rights reserved.

An interesting response to His-synchronous ventricular stimulation: What is the mechanism of this supraventricular tachycardia?"

Inappropriate therapies are frequent in patients with ICDs and are associated with adverse outcomes, including increased mortality. Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common reentrant narrow complex tachycardia and a cause of inappropriate therapies in these patients. The differential diagnosis of narrow QRS complex tachycardia with ventriculoatrial (VA) dissociation or variable block to the atrium is a pivotal role to avoid inappropriate ICD implantation or then shock therapies. This article is protected by copyright. All rights reserved.

Telltale termination of an A-on-V tachycardia with two blocked atrial activations: What is the mechanism?

The termination of tachycardia may provide important clues toward the mechanism of the tachycardia and that close vigilance may clinch the diagnosis before proceeding to other pacing maneuvers.

Unusual response to His-refractory atrial premature complex: What is the mechanism?

A 32-year-old woman underwent radiofrequency catheter ablation of narrow QRS tachycardia that was terminated with intravenous adenosine.