Yongmei Cha, M.D.

Participants in this study will either have heart failure (HF) and are scheduled to undergo cardiac resynchronization therapy pacemaker (CRT-P) or cardiac resynchronization therapy defibrillator (CRT-D) implantation, or have atrioventricular (AV) block and are scheduled to undergo dual chamber pacemaker implantation. In this study additional heart rhythm measurements will be collected during the implant procedure to better understand how His bundle and/or parahisian pacing (HISP) effects electrical conduction in the hearts of patients with HF or AV block. The hypothesis is that His bundle or parahisian pacing (HISP) may normalize atrioventricular (AV) conduction with a narrow combination of the Q wave, R wave and S wave (QRS complex) in functional bundle branch block or conduction delay in patients with heart failure (HF).

The purpose of this study is to determine the long-term outcome of cardiac resynchronization therapy (CRT) recipients with congestive heart failure and any indications for CRT at Mayo Clinic.   

This study is being done to determine whether there is an increase in sympathetic nerve activity before the onset of ventricular arrhythmias.

The purpose of this study is to collect electrogram data from an investigational lead placed in an extravascular space, for the development of a future Implantable Cardioverter Defibrillator (ICD) system.

The purpose of this study is to evaluate the detection performance and safety of an investigational Wearable Cardioverter defibrillator (WCD). 

Congestive heart failure (CHF) affects nearly 5 million Americans and claims more than 300,000 lives annually. A primary pathophysiologic mechanism in this deadly syndrome is an abnormally enhanced sympathetic nervous system that results in profound peripheral vasoconstriction, attenuated cardiovascular reflexes, higher susceptibility to ventricular arrhythmias, and sudden cardiac death. The reduction in mortality and morbidity in CHF by pharmacologic neurohumoral antagonists such as beta-receptor inhibitor and angiotensin II-converting enzyme (ACE) inhibitor has taught us that regulation of the impaired neurohumoral axis is important for improving clinical outcome. In addition, an emerging nonpharmacologic approach, cardiac resynchronization therapy (CRT), has shown promise for improving symptoms and quality of life in patients with New York Heart Association (NYHA) functional class III or IV and intraventricular conduction delay. However, despite significant advances in CHF treatment in the past two decades, a gap remains between clinical outcome and the mechanisms of the protective effects of these modern therapies.

CHF is associated with increased concentrations of circulating norepinephrine (NE), down-regulation of adrenergic nerve terminals, and abnormal NE reuptake. The suppression of cardiac sympathetic nerve endings could be reversed by CRT, a novel anti-heart failure therapy, by rebalance cardiac sympathetic activity, and improve cardiac function in patients with heart failure.

The purpose of the MODULAR ATP Clinical Study is to demonstrate safety, performance, and effectiveness of the Modular Cardiac Rhythm Management (mCRM) Therapy System.

This study is being done to determine if apixaban is more safe, when compared to warfarin, at reducing the risk of bleeding during CIED procedures.

The purpose of this study is to demonstrate safety and effectiveness of the Extravascular Implantable Cardioverter Defibrillator (EV ICD) System.

Medtronic is sponsoring the Micra Continued Access (CA) study to provide continued access to the Micra System while the marketing application is under review by the Food and Drug Administration (FDA).

The purpose of this study is to gather information on the safety and effectiveness of cardiac resynchronization therapy (CRT) in patients who have mild heart failure (HF) and left bundle branch block (LBBB).

The purpose of this study is to gather information to develop and validate a predictive tool for predicting the response to CRT therapy.

The purpose of this clinical study is to evaluate the safety and efficacy of the Micra Transcatheter Pacing System and to assess long term performance.

The purpose of this study is to use a noninvasive method of recording together skin sympathetic nerve activity and electrocardiogram (ECG) to assess the sympathetic activity of the heart. The potential use of this is in the prediction of ventricular arrhymia and identifying the response to resynchronization therapy.

The purpose of this study is to assess the feasibility of enrolling, randomizing treatment strategies and retaining participants with frequent premature ventricular contractions (PVCs) and associated cardiomyopathy (CM).

The purpose of this study is to investigate skin sympathetic nerve activity (SKNA) in correlation with cardiac arrhythmias and/or heart failure.

The purpose of this study is to demonstrate the event rate of the primary outcome, defined as failure of DFT at a single shock at 10 Joules below maximal capacity of the device.

The purpose of this study is to evaluate the safety and effectiveness of the WiSE-LV System for Cardiac Re-synchronization Therapy.

The effect of cardiac pacing leads on tricuspid regurgitation is unclear. This study will determine whether using a smaller diameter leads and an alternate position in the ventricle, the proximal septum, will reduce tricuspid regurgitation than larger leads placed in the apex.

The purpose of this study is to utilize neuECG, a new method to directly and non-invasively record skin sympathetic nerve activity (SKNA) and electrocardiogram (ECG), to non-invasively assess the effects radiofrequency catheter ablation (RFCA) on SKNA in patients at high risk for life-threatening ventricular arrhythmias (VA).

The purpose of this study is to examine characteristic (electrophysiological) of ventricular arrhythmias, ablation technique and outcomes in patients with prosthetic valve.