Supraventricular tachycardia triggering polymorphic ventricular tachycardia

Mitral Valve Prolapse with Syncope: Don't Judge the Book by its Cover!

A 33-year-old female with recurrent syncope episodes showed normal ECG and Holter results, but had mitral valve prolapse (MVP) with moderate mitral regurgitation (MR) on an echocardiogram. Cardiovascular magnetic resonance (CMR) revealed mitral annulus disjunction (MAD) with fibrosis. She received an implantable loop recorder (ILR). Several months later, she experienced a syncope event, which correlated with self-terminating polymorphic ventricular tachycardia (PMVT) preceded by narrow complex tachycardia, which was proven to be atrioventricular nodal reentrant tachycardia (AVNRT) in an electrophysiology study. Post-ablation, she had no recurrences of syncope. This case highlights the importance of ILR in avoiding unnecessary ICDs in MVP patients with syncope.

Message From an Automated External Defibrillator

This case report describes a man in his 80s who received shock from an automated external defibrillator that registered 3 types of tachycardia.

"Narrow-Wide-Narrow" QRS Complex Tachycardia-Beware the Smartwatch Monsters

This case report describes an 18-year-old woman with palpitations associated with chest pain and lightheadedness.

Unusual presentation of supraventricular tachycardia degenerating into ventricular fibrillation during pregnancy: Aortocaval compression the probable culprit

Cardiac arrhythmias are common and often benign in pregnancy. However, haemodynamic instability can occur when tachyarrhythmias are accompanied by aortocaval compression, which can lead to loss of cardiac output. We present an atypical case of a pregnant woman with a supraventricular tachyarrhythmia, which degenerated into ventricular fibrillation arrest while supine due to aortocaval compression. Inducible atypical atrioventricular nodal re-entry tachycardia was subsequently detected on electrophysiological study and presumed to be the most likely initial supraventricular tachyarrhythmia.

Catheter ablation via the left atrium for atrioventricular nodal reentrant tachycardia: A narrative review

Background

Since 1996, it has been recognized that catheter ablation for atrioventricular nodal reentrant tachycardia (AVNRT) may require an approach through the left atrium.

Objective

The purposes are to present a case report and to provide a comprehensive narrative review on this topic.

Methods

A literature review of all articles that provided detailed information on patients who underwent catheter ablation via the left atrium for AVNRT was performed. The primary search queried PubMed using Medical Subject Headings (MeSH) terms "atrioventricular nodal reentrant tachycardia" and "left." The secondary search was performed by manual review of reference lists and Google Scholar citations of manuscripts retrieved by the primary search. The review was limited to the English language.

Results

The searches yielded 30 articles that described 79 patients. A case report was added. Therefore, the final review consisted of 80 patients. The prevalence of left atrial ablation for patients with AVNRT undergoing catheter ablation at tertiary care centers was approximately 1%. Failed right atrial ablation, with or without coronary sinus ablation, was the most common indication for left atrial ablation. Pooled data from 3 cohort studies estimated the acute success rate for radiofrequency ablation of the slow pathway at the septal or inferoparaseptal segments of the mitral valve annulus after failed right-sided ablation to be 90%. There were no reports of atrioventricular block requiring permanent pacemaker implantation.

Conclusion

Catheter ablation of the slow pathway via the left atrium is an important technique for AVNRT cases that are refractory to conventional ablation.