Physiology of slow pathway conduction during sinus rhythm: evidence from high density mapping within the triangle of Koch.

Purpose: To evaluate nature of AV nodal activation in patients with AVNRT using high density electro-anatomic mapping (HD-EAM).

Methods: HD-EAM was created in 30 patients with AVNRT from the triangle of Koch (ToK) in sinus rhythm (SR). Isochronal late activation maps (ILAM) were created.

Direct Current Ablation of Deep Substrate Arrhythmia.

Direct-current ablation has been reinvestigated in animal models with considerably good outcomes and safety margins. Its modified version using biphasic energy lowers the current density further, minimizing its complications. We report a first-in-human ablation of ventricular tachycardia using biphasic direct current with short-term success and no procedural complications.

Substrate Targeted Ablation of Atrial Fibrillation Guided by High Density Voltage Mapping: Long-Term Results.

Background: Long-term ablation results for atrial fibrillation (AF) have been disappointing, particularly for non-paroxysmal AF (NPAF). We hypothesize fibrosis in paroxysmal AF (PAF) and NPAF would be reflected in voltage fragmentation and visualized by high density mapping. Targeted ablation of discrete low voltage bridges (LVB) would eliminate endocardial fragmentation and should have a positive effect on long-term sinus rhythm (SR) survival.

Epicardial bridge via the coronary sinus musculatures revealed by ultra-high-definition mapping.

Mapping and ablation of perimitral flutter, a macro-reentrant tachycardia, can be sometimes challenging. We describe a case of perimitral atrial flutter following the pulmonary vein isolation in which mitral isthmus ablation failed to terminate the arrhythmia due to epicardial-endocardial breakthrough via the muscle fibers of coronary sinus. Ultra-high-definition mapping system was utilized to locate the epicardial bridge, and spot ablation of the lesion subsequently terminated the arrhythmia.

Air Entrapment Causing Inappropriate Shock From a Subcutaneous Implantable Cardioverter Defibrillator.

Subcutaneous implantable cardioverter defibrillator (S-ICD) is an accepted alternative to conventional transvenous devices. Their efficacy in arrhythmia management is comparable to ICDs. However, those devices also have limitations such as lack of anti-tachycardia pacing capability or higher occurrence of device oversensing associated with inappropriate shocks.

A new methodology for atrial flutter ablation by direct visualization of cavotricuspid conduction with voltage gradient mapping: a comparison to standard techniques.

Aims: To demonstrate that critical conduction within the cavotricuspid isthmus (CTI) can be directly visualized by voltage gradient mapping and facilitate efficient ablation compared to standard techniques.

Methods And Results: Group 1 (1 operator, n = 11) ablated based upon contact voltage measurements and voltage gradient mapping. Ablation targeted low-voltage bridges (LVBs) within the CTI.

Direct visualization of the slow pathway using voltage gradient mapping: a novel approach for successful ablation of atrioventricular nodal reentry tachycardia.

Aims: Ablation of atrioventricular nodal reentry tachycardia (AVNRT) has become treatment of choice because of a high success and low complication rate. Most ablations are successful in utilizing an anatomic approach, but anatomic variance, unusual pathway locations, or multiple pathways may complicate the procedure. Visualization of the slow pathway could expedite ablation success and enhance safety.

Is Bachmann's Bundle the only right site for single-site pacing to prevent atrial fibrillation? Results of a multicenter randomized trial.

The site of atrial pacing influences atrial activation patterns. It is believed that disparities in atrial activation and repolarization are contributors to the development and recurrence of atrial arrhythmias. We hypothesized that pacing from Bachmann's Bundle would improve clinical outcomes in patients with paroxysmal atrial fibrillation compared to right atrial appendage pacing.

Lack of a hypotensive effect with rapid administration of a new aqueous formulation of intravenous amiodarone.

Hypotension is the most frequent adverse event reported with intravenous amiodarone. Hypotension has been attributed to the vasoactive solvents of the standard formulation (Cordarone IV) and is not dose related, but related to the rate of infusion. Drug labeling calls for intravenous amiodarone to be administered over 10 minutes.

Clinical investigation of a new dual-chamber implantable cardioverter defibrillator with improved rhythm discrimination capabilities.

Introduction: Despite continuing advances, inappropriate implantable cardioverter defibrillator (ICD) therapies in response to nonventricular tachyarrhythmias continue to cause patient discomfort and increased follow-up demands.

Methods And Results: We investigated the performance of a new dual-chamber ICD (Photon DR, St. Jude Medical), with specific attention to its arrhythmia discrimination and detection capabilities.

Bachmann's bundle versus right atrial appendage capture.

The tissue in the high intraatrial septum in the region of Bachmann's Bundle (BB) exhibits electrophysiological properties that differ from the right atrial appendage (RAA). As BB pacing emerges as an alternative to RAA pacing, the feasibility of using automatic capture recognition technology in this location should be examined. At implant, active-fixation leads were consecutively placed in the RAA, then the BB in 18 patients (55.

Intravenous lidocaine versus intravenous amiodarone (in a new aqueous formulation) for incessant ventricular tachycardia.

The effectiveness of intravenous amiodarone for the treatment of incessant (shock resistant) ventricular tachycardia (VT) has not been established. This study evaluated the efficacy of a water-soluble amiodarone preparation or lidocaine for the treatment of shock-resistant VT. The trial was a double-blinded parallel design.