Site-Specific Ventricular Tachycardia Inducibility.

Background: Programmed electrical stimulation (PES) is an essential part of ventricular tachycardia (VT) ablation procedures, but VT is not always inducible, usually for reasons that are not clear.

Objectives: This study sought to review pacing site-specific failure of PES to induce scar-related VT and to provide a potential mechanistic explanation of the phenomena using a computer simulation.

Methods: Six patients in whom aggressive PES from traditional RV pacing sites failed to induce VT, but VT was easily inducible from a nontraditional site, were reviewed.

Percutaneous VT Ablation via RA-to-LV Access in Patients With Double Mechanical Valves: A Multicenter Registry.

Background: In patients with mechanical aortic and mitral valves requiring catheter ablation of ventricular tachycardia (VT), a technique for access from the right atrium (RA) to the left ventricle (LV) via puncture of the inferoseptal process of the LV was previously described in a single-center series.

Objectives: This study sought to report the multicenter experience of VT ablation using this novel LV access approach.

Methods: We assembled a multicenter registry of patients with double mechanical valves who underwent VT ablation with RA-to-LV access.

Idiopathic Annular Ventricular Arrhythmias.

Idiopathic arrhythmias originating from the mitral and tricuspid annuli are commonly encountered in clinical practice. This review focuses on distinguishing features of ventricular arrhythmias arising from these structures and the importance of distinguishing idiopathic arrhythmias from those associated with structural heart disease. Each region along the mitral and tricuspid annuli (including the cardiac crux and para-Hisian region) is then discussed separately, with a particular emphasis on the ablation strategies and pitfalls for each.

MRI findings in six dogs with ependymoma of the brain and spinal cord.

There are few published descriptions of the MRI appearance of canine intracranial or spinal cord ependymoma. In this multicenter, retrospective, secondary analysis, case series study, three veterinary radiologists independently reviewed and recorded imaging characteristics of MRI studies in six dogs with histopathologically confirmed ependymoma (three intracranial and three spinal cord cases). A consensus was reached when there was disagreement on specific features.