Samuel J. Asirvatham, M.D.

The purpose of this study is to verify that high Premature Ventricular Complex (PVC) burden is associated with increased risk of stroke and/or Transient Ischemic Attack (TIA), to examine outcomes such as stroke/TIA, atrial fibrillation/flutter, and all-cause mortality associated with PVCs, and to evaluate whether PVCs are associated with development of appendage dysfunction.

The purpose of this study is to obtain electro-anatomic maps of human myocardium in sinus rhythm and ventricular arrhythmias to identify activation patterns, identify and perform tissue ablation at targeted sites of interest that could play an important trigger for development of arrhythmias, and to perform histologic analysis of the myocardial tissue to identify triggers and/or targets for therapies to terminate ventricular arrhythmias.

The purpose of this study is to refine the technique for non-invasively determined potassium measurement and to determine whether or not the technique can be realized in a single channel-subcutaneous ECG implementation modality.

The purpose of this study is to learn about the effect of atrial fibrillation on memory and thinking. This study helps us to determine how often memory problems occur in patients with atrial fibrillation and identify factors that influence changes in memory and thinking.

Patients with a patent foramen ovale in the setting of endocardially placed cardiac implantable electronic devices such as pacemakers, defibrillators, or resynchronization therapies are likely at higher risk for paradoxical embolic events from device lead thrombus. The investigators are conducting this study to determine if the anticoagulant medication Apixaban is more effective at reducing MRI detected brain lesions compared to placebo.

Participants enrolled in this study will have been diagnosed with patent foramen ovale (PFO) and have been scheduled to have a cardiovascular implantable electronic device (CIED) such as a pacemaker, implantable cardioverter-defibrillator (ICD), or cardiac resynchronization therapy (CRT) device implanted. A PFO is a condition when there is a hole in the septum (the wall separating the right and left sides) of the heart. The purpose of this study is to determine whether closing the PFO with the GORE® Cardioform Septal Occluder in people with an endocardial device leads reduces the risk of recurrent stroke or imaging-confirmed transient ischemic attack (TIA) compared to not closing the PFO.

This study aims to perform a prospective analysis of patients undergoing fibrillation ablations and compare the validity of the electroanatomical registration with superimposed angiography. In addition, this study aims to compare and understand the relationship between the cardiac vessels.