BACKGROUND Transmural scar occupying left ventricular (LV) pacing regions has been associated with reduced response to cardiac resynchronization therapy (CRT). However, spatial influences of lead tip delivery relative to scar at both pacing sites remain poorly explored. This study evaluated scar distribution relative to LV and right ventricular (RV) lead tip placement through coregistration of ...

Background: Despite the progress of cardiac arrhythmia research and the advance of the pacemaker technology, much remains unknown about how the external pacing interacts with the heart’s intrinsic activity. Methods: We present an open source computer model that is capable to simulate intrinsic heart rhythm under both normal and pathological conditions, and its interactions with extrinsic dual-c...

The heterotopically transplanted rat heart undergoes significant atrophy and a shift from V1 to V3 isomyosin. The purpose of this study was to pace the cardiac isograft and determine whether an increase in heart rate would attenuate the changes in cardiac mass and isoenzyme distribution. Nonpaced transplanted hearts were compared with hearts in which pacing was initiated at 7 Hz, 24 hours after...

The safety and efficacy of temporary pericardial pacing wires have been accepted and their use is common after cardiac operations. Complications related to pacing wire removal are unusual but it can be serious and even catastrophic. We report an unusual case of bleeding due the laceration and rent created in the saphenous vein graft wall by the metallic tip of the pacing wire at the time of pac...

BACKGROUND In patients with triple valve replacement developing third-degree atrioventricular block (AVB), the most appropriate approach for permanent pacemaker implantation remains questionable. CASE PRESENTATION In this case presentation, we first described the approach of implantation of the cardiac resynchronization therapy pacemaker (CRT-P) via one bipolar pacing lead in middle cardiac v...

We sought to evaluate the impact of biventricular (BiV) pacing with ventricular fusion by intrinsic atrioventricular nodal (AVN) conduction (BiV + intrinsic pacing) on clinical outcomes in patients with chronic heart failure (CHF) receiving cardiac resynchronization therapy (CRT).A total of 44 patients were randomized to receive either BiV or BiV + intrinsic pacing for one month. Echocardiograp...

We describe the case of a 37-year-old woman who presented with complete right bundle branch block and right axis deviation. She was admitted to our hospital due to severe heart failure and was dependent on inotropic agents. Cardiac resynchronization therapy was initiated but did not improve her condition. After the optimization of the pacing timing, we performed earlier right ventricular pacing...

Reentrant waves propagating in a ring or annulus of excitable media are a model of the basic mechanism underlying a major class of irregular cardiac rhythms known as anatomical reentry. Such reentrant waves are terminated by rapid electrical stimulation (pacing) from an implantable device. Because the mechanisms of such termination are poorly understood, we study pacing of anatomical reentry in...

We report a patient who did not improve after standard optimization of atrioventricular and intraventricular pacing timing, but showed response to cardiac resynchronization therapy (CRT) after increasing left ventricular (LV) pacing output. Increasing LV pacing output is one of the useful optimization methods for CRT nonresponder.

OBJECTIVES Biventricular pacing acutely improves left ventricular function in patients with heart failure and left ventricular dyssynchrony. Pressure-volume loop analysis has shown acute perioperative hemodynamic benefits of biventricular pacing immediately after weaning from cardiopulmonary bypass in patients undergoing coronary artery bypass grafting, but whether these effects can be maintain...