Role of interatrial conduction in atrial fibrillation: Mechanistic insights from renewal theory-based fibrillatory dynamic analysis.

Background: Interatrial conduction has been postulated to play an important role in atrial fibrillation (AF). The pathways involved in interatrial conduction during AF remain incompletely defined.

Objective: We recently showed physiological assessment of fibrillatory dynamics could be performed using renewal theory, which determines rates of phase singularity formation (λ) and destruction (λ).

Prospective cross-sectional study using Poisson renewal theory to study phase singularity formation and destruction rates in atrial fibrillation (RENEWAL-AF): Study design.

Background: Unstable functional reentrant circuits known as rotors have been consistently observed in atrial fibrillation and are mechanistically believed critical to the maintenance of the arrhythmia. Recently, using a Poisson renewal theory-based quantitative framework, we have demonstrated that rotor formation (λ) and destruction rates (λ) can be measured using in vivo electrophysiologic data. However, the association of λ and λ with clinical, electrical, and structural markers of atrial fibrillation phenotype is unknown.

A Randomised Controlled Trial on the Effect of Nurse-Led Educational Intervention at the Time of Catheter Ablation for Atrial Fibrillation on Quality of Life, Symptom Severity and Rehospitalisation.

Background: Atrial Fibrillation (AF) is a common condition associated with impaired quality of life (QOL) and recurrent hospitalisation. Catheter ablation for AF is a well-established treatment for symptomatic patients despite medical therapy. We sought to examine the effect of point specific nurse-led education on QOL, AF symptomatology and readmission rate post AF ablation.

Assessment of oesophageal position by direct visualization with luminal contrast compared with segmentation from pre-acquired computed tomography scan-implications for ablation strategy.

Aims: Atrio-oesophageal fistula is a rare but often fatal complication of catheter ablation for atrial fibrillation (AF). Various strategies are employed to evaluate the oesophageal position in relation to the posterior left atrium (LA). These include segmentation of the oesophagus from a pre-acquired computed tomography (CT) scan and direct, real-time assessment of the oesophageal position using contrast at the time of the procedure.

Vertebral artery dissection secondary to defibrillation threshold testing.

We report a case of vertebral artery dissection presenting 2 days after ICD implantation with defibrillation threshold testing in a 57-year-old man with ischemic cardiomyopathy. The association between vertebral artery dissection and neck trauma and the role of DFT testing in ICD implantation are discussed.

Pulmonary venous isolation versus additional substrate modification as treatment for paroxysmal atrial fibrillation.

Background: Pulmonary vein isolation alone is ineffective in maintaining sinus rhythm in up to one third of patients with paroxysmal atrial fibrillation (AF). We compared pulmonary vein antral isolation plus additional limited ablation along the inferoposterior left atrium and epicardially within the adjacent coronary sinus (PVAI + CS) to pulmonary vein antral isolation (PVAI) alone in patients with paroxysmal AF.

Methods: Forty-two consecutive patients with paroxysmal AF were prospectively randomized to PVAI vs.

Left ventricular outflow tract ventricular tachycardia originating from the noncoronary cusp: electrocardiographic and electrophysiological characterization and radiofrequency ablation.

Noncoronary cusp (NCC) ventricular tachycardia is a rare form of monomorphic outflow tract tachycardia, and its electrocardiographic and electrophysiological characteristics have not been well described previously. The NCC should be considered for catheter ablation if attempts to eliminate ventricular tachyarrhythmia were unsuccessful in the other common anatomical sites of the left ventricular outflow tract.

Effects of components of ischemia on the Kv4.3 current stably expressed in Chinese hamster ovary cells.

We investigated the effects of three components of ischemia: external acidosis (pH=6.0), extracellular hyperkalemia ([K(+)]=20 mmol/l), and resting membrane depolarization to -60 mV, on Kv4.3 current stably expressed in Chinese Hamster Ovary cells.