The Role of Adenosine in Pulmonary Vein Isolation: A Critical Review

The cornerstone of atrial fibrillation (AF) ablation is pulmonary vein isolation (PVI), which can be achieved in more than 95% of patients at the end of the procedure. However, AF recurrence rates remain high and are related to recovery of PV conduction. Adenosine testing is used to unmask dormant pulmonary vein conduction (DC). The aim of this study is to review the available literature addressing the role of adenosine testing and determine the impact of ablation at sites of PV reconnection on freedom from AF. Adenosine infusion, by restoring the excitability threshold, unmasks reversible injury that could lead to recovery of PV conduction. The studies included in this review suggest that adenosine is useful to unmask nontransmural lesions at risk of reconnection and that further ablation at sites of DC is associated with improvement in freedom from AF. Nevertheless it has been demonstrated that adenosine is not able to predict all veins at risk of later reconnection, which means that veins without DC are not necessarily at low risk. The role of the waiting period in the setting of adenosine testing has also been analyzed, suggesting that in the acute phase adenosine use should be accompanied by enough waiting time

Cardiac MRI to Investigate Myocardial Scar and Coronary Venous Anatomy Using a Slow Infusion of Dimeglumine Gadobenate in Patients Undergoing Assessment for Cardiac Resynchronization Therapy

n/

Voxel based adaptive meshless method for cardiac electrophysiology simulation

In this paper, an adaptive meshless method is described for solving the modified FitzHugh Nagumo equations on a set of nodes directly imported from the voxels of the medical images. The non-trivial task of constructing suitable meshes for complex geometries to solve the reaction-diffusion equations is circumvented by a meshfree implementation. The spatial derivatives arising in the reaction diffusion system are estimated using the Lagrangian form of scattered node radial basis function interpolant. Normal cardiac activation phenomena is fast, with a very steep upstroke and localised as compared to the size of the computational domain. To accurately capture this phenomena, a space adaptive method is presented where extra nodes are placed near the region of the activation front. The performance of the adaptive method is investigated first for synthetic geometry and then applied to a real-life geometry obtained from magnetic resonance imaging. Numerical results suggest that the presented method is capable of predicting realistic electrophysiology simulation effectivel