Matthew P Smelley

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The incidence of persistent and permanent AF will likely continue to increase as the population ages and as patients with structural heart disease live longer. Many catheter-based ablation techniques have been developed to treat AF. This paper will review which of these approaches have been demonstrated to be effective for ablation of persistent and(More)
BACKGROUND The Medtronic Sprint Fidelis defibrillator lead has a high failure rate and was recalled in October 2007. OBJECTIVE The purpose of this study was to determine the incremental cost of the management of this lead to Medicare. METHODS Real hospital cost data in U.S. dollars were collected on 32 patients with a Medtronic Sprint Fidelis lead who(More)
BACKGROUND A hypertensive response to exercise (HRE) is associated with false-positive stress echocardiograms and myocardial perfusion single photon emission computed tomography (myocardial perfusion imaging [MPI]) defects even in the absence of coronary artery disease (CAD). Transient ischemic dilation (TID) of the left ventricle on stress MPI is a marker(More)
The differential for a large mass impinging on the left atrium should include a hiatal hernia. When a hiatal hernia is suspected, the patient can be asked to ingest a carbonated beverage. Oftentimes, the beverage and bubbles can help delineate the herniation on echocardiography. This technique can make the diagnosis, but it is not always successful. WE(More)
Current electrocardiographic technology is limited in its ability to detect pacemaker stimuli secondary to the use of 150 Hz low-pass bandwidth filters designed to block high-frequency interference. Software solutions to improve the sensitivity of pacemaker stimulus detection are associated with imperfect specificity. The following case reports include(More)
INTRODUCTION The purpose of this study was to determine the safety and efficacy of using a novel radiofrequency (RF) powered transseptal needle to perform transseptal puncture (TSP). METHODS TSP was performed in 35 consecutive patients undergoing left-sided catheter ablation (mean age = 51 years; male = 71%) using a RF powered transseptal needle (NRG,(More)
Adenosine triphosphate-sensitive potassium (K(ATP)) channels are thought to mediate the stress response by sensing intracellular ATP concentration. Cardiomyocyte K(ATP) channels are composed of the pore-forming Kir6.2 subunit and the regulatory sulfonylurea receptor 2 (SUR2). We studied the response to acute isoproterenol in SUR2 null mice as a model of(More)
In the vasculature, ATP-sensitive potassium channels (KATP) channels regulate vascular tone. Mice with targeted gene disruptions of KATP subunits expressed in vascular smooth muscle develop spontaneous coronary vascular spasm and sudden death. From these models, it was hypothesized that the loss of KATP channel activity in arterial vascular smooth muscle(More)
INTRODUCTION Insulation defects are a leading cause of transvenous lead failure. The purpose of this study was to determine the effects of electrocautery on transvenous lead insulation materials. METHODS A preparation was done to simulate dissection of a transvenous lead from tissues. Radiofrequency energy was delivered using a standard cautery blade at(More)
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