Pharmacological Modulation of Right Ventricular Endocardial-Epicardial Gradients in Brugada Syndrome.

Background We explored the hypothesis that increased cholinergic tone exerts its proarrhythmic effects in Brugada syndrome (BrS) through increasing dispersion of transmural repolarization in patients with spontaneous and drug-induced BrS. Methods BrS and supraventricular tachycardia patients were studied after deploying an Ensite Array in the right ventricular outflow tract and a Cardima catheter in the great cardiac vein to record endo and epicardial signals, respectively. S-S restitution curves from the right ventricular apex were conducted at baseline and after edrophonium challenge to promote increased cholinergic tone.

Effect of mental stress on dynamic electrophysiological properties of the endocardium and epicardium in humans.

Background: Striking temporal associations exist between ventricular arrhythmia and acute mental stress, for example, during natural disasters, or defibrillator shocks associated with stressful events. We hypothesized that electrophysiological changes in response to mental stress may be exaggerated at short coupling intervals and hence relevant to arrhythmia initiation.

Objective: The aim of this study was to determine the dynamic response in human electrophysiology during mental stress.

Dynamic conduction and repolarisation changes in early arrhythmogenic right ventricular cardiomyopathy versus benign outflow tract ectopy demonstrated by high density mapping & paced surface ECG analysis.

Aims: The concealed phase of arrhythmogenic right ventricular cardiomyopathy (ARVC) may initially manifest electrophysiologically. No studies have examined dynamic conduction/repolarization kinetics to distinguish benign right ventricular outflow tract ectopy (RVOT ectopy) from ARVC's early phase. We investigated dynamic endocardial electrophysiological changes that differentiate early ARVC disease expression from RVOT ectopy.

Noncontact mapping guided ablation of right ventricular outflow tract ectopy in a patient with interruption of the inferior vena cava and azygos continuation.

A 58-year-old woman with symptomatic multiple monomorphic premature ventricular beats of a right ventricular outflow tract origin was referred for ablation. An inferior vena cava interruption with azygos continuation was discovered during catheter placement. This case describes positioning of the noncontact mapping array and successful radiofrequency ablation in this challenging anatomy.

High-density substrate mapping in Brugada syndrome: combined role of conduction and repolarization heterogeneities in arrhythmogenesis.

Background: Two principal mechanisms are thought to be responsible for Brugada syndrome (BS): (1) right ventricular (RV) conduction delay and (2) RV subepicardial action potential shortening. This in vivo high-density mapping study evaluated the conduction and repolarization properties of the RV in BS subjects.

Methods And Results: A noncontact mapping array was positioned in the RV of 18 BS patients and 20 controls.