Tricuspid valve (TV) disease (which includes surgical repair) can impede transvenous endocardial right ventricular pacing. A lead crossing the TV can damage and be damaged by the valve, especially in the presence of mechanical prostheses (valve, annuoplasty ring, artificial chordae). Surgical epicardial lead placement requires sternotomy or thoracotomy and pericardotomy, with associated morbidi...

OBJECTIVE To evaluate whether thromboembolism in sick sinus syndrome can be predicted by pacing mode, atrial fibrillation, or echocardiographic findings. METHODS Patients were randomised to single chamber atrial (n = 110) or ventricular (n = 115) pacing. They were divided into subgroups with and without brady-tachy syndrome at time of randomisation. The occurrence of atrial fibrillation and t...

INTRODUCTION The effect of Angiotensin-(1-7) (Ang-(1-7)) on atrial autonomic remodeling is still unknown. We hypothesized that Ang-(1-7) could inhibit sympathetic nerve remodeling in a canine model of chronic atrial tachycardia. MATERIALS AND METHODS Eighteen dogs were randomly assigned to sham group, pacing group and Ang-(1-7) group. Rapid atrial pacing was maintained for 14 days in the paci...

Although atrial synchronous and rate-responsive ventricular pacing have been compared, the importance of maintaining synchronized atrial systole in addition to rate responsiveness has been incompletely defined. That is, the effects of these two pacing modes on cardiac volumes and contractility have not been studied. Accordingly, 16 patients with normal ventricular function were studied while in...

BACKGROUND It recently has been demonstrated that during atrial fibrillation, a short and variable excitable gap exists, allowing regional control of atrial fibrillation by local stimulation. In the present study, we visualized the process of excitation during regional entrainment of atrial fibrillation by rapid pacing. METHODS AND RESULTS In six open-chest dogs, the excitation of the left at...

A 68-year-old man with sick sinus syndrome (SSS) was referred to our department for pacemaker implantation. After implantation of a pacemaker with rate-responsive dual chamber (DDDR) mode and minimized ventricular pacing (MVP) functions, paroxysmal atrial fibrillation (PAF) repeatedly developed. Pacemaker memory showed that the intrinsic atrioventricular (AV) (atrial pacing-ventricular sensing ...

The effect of cardiac pacing, through a wide range of pacing rates, has been studied in 13 patients in stable sinus rhythm within 24 hours of operation. Using first atrial and then ventricular pacing, the cardiac rate was raised to 60% above control value. The effects of atrial and ventricular pacing were compared by observing the differences in the various parameters measured at corresponding ...

BACKGROUND Active fixation leads have provided stable atrial and ventricular pacing; however, long-term follow-up data have not been satisfactory. The purpose of this study was to investigate the long-term reliability of active fixation leads and their electrical characteristic stability. METHODS A total of 1196 pacing leads were implanted in 830 patients consecutively between 2002 and 2013. ...

The relation between QT interval and heart rate has been studied in a group of patients undergoing physiological exercise, in a group undergoing atrial pacing without exercise, and in a group with complete heart block undergoing exercise at a fixed ventricular rate controlled by cardiac pacing. The expected shortening in QT interval during physiological exercise is only in part the result of th...

A permanent transvenous pacemaker lead was placed across the atrial septum and retained in the left ventricle for eight years. M-mode echocardiograms showed a linear echocardiographic density in the left atrium and mitral valve. Cross-sectional echocardiograms further defined the location and course of the pacing lead.