Spontaneous resumption of severe infranodal conduction disturbances that followed COVID-19 vaccination.

We report reversible severe infranodal conduction disturbances that followed COVID-19 vaccination in a young woman. Right and left bundle branch conduction were impaired and recovered at different times, resulting in reversible paroxysmal complete atrioventricular block.

Premature ventricular contraction arising from the left coronary sinus cusp: Which signal is the target of ablation?

We described a premature ventricular contraction arising from the left coronary sinus cusp, in which we discussed about the interpretations of the signals recorded there. Our case provided further insights into the interpretation of signals recorded at the coronary sinus cusp during premature ventricular contraction ablation.

Demonstration of differential ventricular overdrive pacing during long RP' supraventricular tachycardia.

We described the differential ventricular overdrive pacing during long RP' supraventricular tachycardia and discussed about its response leading to the dianosis.

Age-related nitration/dysfunction of myogenic stem cell activator HGF.

Mechanical perturbation triggers activation of resident myogenic stem cells to enter the cell cycle through a cascade of events including hepatocyte growth factor (HGF) release from its extracellular tethering and the subsequent presentation to signaling-receptor c-met. Here, we show that with aging, extracellular HGF undergoes tyrosine-residue (Y) nitration and loses c-met binding, thereby disturbing muscle homeostasis. Biochemical studies demonstrated that nitration/dysfunction is specific to HGF among other major growth factors and is characterized by its locations at Y198 and Y250 in c-met-binding domains.

The value of functional substrate mapping in ventricular tachycardia ablation.

In the setting of structural heart disease, ventricular tachycardia (VT) is typically associated with a re-entrant mechanism. In patients with hemodynamically tolerated VTs, activation and entrainment mapping remain the gold standard for the identification of the critical parts of the circuit. However, this is rarely accomplished, as most VTs are not hemodynamically tolerated to permit mapping during tachycardia.

High-resolution mapping of reentrant atrial tachycardias: Relevance of low bipolar voltage.

Background: Bipolar voltage is widely used to characterize the atrial substrate but has been poorly validated, particularly during clinical tachycardias.

Objective: The purpose of this study was to evaluate the diagnostic performance of voltage thresholds for identifying regions of slow conduction during reentrant atrial tachycardias (ATs).

Methods: Thirty bipolar voltage and activation maps created during reentrant ATs were analyzed to (1) examine the relationship between voltage amplitude and conduction velocity (CV), (2) measure the diagnostic ability of voltage thresholds to predict CV, and (3) identify determinants of AT circuit dimensions.

Atrial activation sequence changes during ventricular overdrive pacing: What is the mechanism?

We describe atrial activation sequence changes during ventricular overdrive pacing in a patient with a concealed left-sided accessory pathway and discuss its potential mechanism.

A pilot study on nitration/dysfunction of NK1 segment of myogenic stem cell activator HGF.

Protein tyrosine residue (Y) nitration, a post-translational chemical-modification mode, has been associated with changes in protein activity and function; hence the accumulation of specific nitrated proteins in tissues may be used to monitor the onset and progression of pathological disorders. To verify the possible impact of nitration on postnatal muscle growth and regeneration, a pilot study was designed to examine the nitration/dysfunction of hepatocyte growth factor (HGF), a key ligand that is released from the extracellular tethering and activates myogenic stem satellite cells to enter the cell cycle upon muscle stretch and injury. Exposure of recombinant HGF (a hetero-dimer of α- and β-chains) to peroxynitrite induces Y nitration in HGF α-chain under physiological conditions.

True Brugada syndrome ECG or Brugada phenocopy ECG? Can the ECG itself tell us the diagnosis?

We described a type 1 Brugada electrocardiogram and discussed about the potential diagnostic electrocardiographic indicators to differentiate true Brugada syndrome and Brugada phenocopy.

Distribution of atrial low voltage induced by vein of Marshall ethanol infusion.

Introduction: Systematic and quantitative descriptions of vein of Marshall (VOM)-induced tissue ablation are lacking. We sought to characterize the distribution of low voltage observed in the left atrium (LA) after VOM ethanol infusion.

Methods And Results: The distribution of ethanol-induced low voltage was evaluated by comparing high-density maps performed before and after VOM ethanol infusion in 114 patients referred for atrial fibrillation ablation.

Strategy for repeat procedures in patients with persistent atrial fibrillation: Systematic linear ablation with adjunctive ethanol infusion into the vein of Marshall versus electrophysiology-guided ablation.

Introduction: The optimal strategy after a failed ablation for persistent atrial fibrillation (perAF) is unknown. This study evaluated the value of an anatomically guided strategy using a systematic set of linear lesions with adjunctive ethanol infusion into the vein of Marshall (Et-VOM) in patients referred for second perAF ablation procedures.

Methods And Results: Patients with perAF who underwent a second procedure were grouped according to the two strategies.

Preoperative personalization of atrial fibrillation ablation strategy to prevent esophageal injury: Impact of changes in esophageal position.

Introduction: Due to changes in esophageal position, preoperative assessment of the esophageal location may not mitigate the risk of esophageal injury in catheter ablation for atrial fibrillation (AF). This study aimed to assess esophageal motion and its impact on AF ablation strategies.

Methods And Results: Ninety-seven AF patients underwent two computed tomography (CT) scans.