Atrioventricular Nodal Reentrant Tachycardia in Implantable Cardioverter Defibrillators: Diagnosis and Troubleshooting

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.

Successful Identification of and Discrimination Between Atrial and Ventricular Arrhythmia with the Aid of Pacing and Defibrillator Devices

The presence of supraventricular tachycardia is the leading cause of inappropriate shock in ICD recipients, and it can be a significant cause of morbidity, psychological distress and worsened clinical outcome. Modern pacing and ICD systems offer a number of discriminators that are integrated into algorithms to differentiate sustained ventricular tachycardia from supraventricular tachycardia. These algorithms can be adapted and optimised for each individual patient to ensure that only those arrhythmias that need treatment through the use of an ICD, are actually treated. This review summarises the single- and dual-chamber discriminators that can be used in the detection and classification of tachyarrhythmias.

Clinical predictors of heart block during atrioventricular nodal reentrant tachycardia ablation: A multicenter 18-year experience

BACKGROUND

Catheter ablation is considered the first-line treatment of symptomatic atrioventricular nodal reentrant tachycardia (AVNRT). It has been associated with a risk of heart block (HB) requiring a pacemaker. This study aims to determine potential clinical predictors of complete heart block as a result AVNRT ablation.

METHODS

Consecutive patients undergoing catheter ablation for AVNRT from January 2001 to June 2019 at two tertiary hospitals were included. We defined ablation-related HB as the unscheduled implantation of pacemaker within a month of the index procedure. Use of electroanatomic mapping (EAM), operator experience, inpatient status, age, sex, fluoroscopy time, baseline PR interval, and baseline HV interval was included in univariate and multivariate models to predict HB post ablation.

RESULTS

In 1708 patients (56.4 ± 17.0 years, 61% females), acute procedural success was 97.1%. The overall incidence of HB was 1.3%. Multivariate analysis showed that age more than 70 (odds ratio [OR] 7.907, p ≤ .001, confidence interval [CI] 2.759-22.666), baseline PR ≥ 190 ms (OR 2.867, p = .026, CI 1.135-7.239) and no use of EAM (OR 0.306, p = .037, CI 0.101-0.032) were independent predictors of HB.

CONCLUSION

Although the incidence of HB post AVNRT ablation is generally low, patients can be further stratified using three simple predictors.

ATP - A friend with benefits

Anti-tachycardia pacing (ATP) has gained widespread acceptance to treat ventricular tachyarrhythmias and prevent implantable defibrillator shocks. A 63-year-old lady with nonischemic cardiomyopathy underwent insertion of a primary prevention biventricular implantable cardioverter defibrillator (BIV-ICD). Post implant she was found to have recurrent episodes of atrioventricular nodal re-entry tachycardia (AVNRT) based on device electrograms. In this report, we describe the use of anti-tachycardia pacing to manage this tachycardia.

Catheter Ablation of Atrioventricular Nodal Re-entrant Tachycardia: Facts and Fiction

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Atrioventricular 1:1 tachycardia effectively terminated by antitachycardia pacing : What is your diagnosis?

This case describes a tachycardia with a 1:1 atrioventricular relationship that was effectively terminated with antitachycardia pacing by the implantable cardioverter defibrillator. The differential diagnosis and clues that allow the reader to establish the correct diagnosis are discussed. The case also serves to analyse technical features of Boston Scientific dual-chamber defibrillators.