OBJECTIVES The purpose of this study was twofold: to assess whether biatrial pacing is superior to single-site pacing and capable of reducing the frequency of episodes of paroxysmal atrial fibrillation (PAF); and to compare pacing of the proximal coronary sinus (PCS) with the distal coronary sinus (DCS) and the effects of sequential or simultaneous biatrial pacing. BACKGROUND Interatrial cond...

We aimed to determine whether sex differences in humans extend to the dynamic response of the left ventricular (LV) chamber to changes in heart rate (HR). Several observations suggest sex influences LV structure and function in health; moreover, this physiology is also affected in a sex-specific manner by aging. Eight postmenopausal women and eight similarly aged men underwent a cardiac cathete...

It is well known that there is considerable spatial inhomogeneity in the electrical properties of heart muscle, and that the many interventions that increase this initial degree of inhomogeneity all make it easier to induce certain cardiac arrhythmias. We consider here the specific example of myocardial ischemia, which greatly increases the electrical heterogeneity of ventricular tissue, and of...

OBJECTIVES This study was designed to assess the impact of prevention of bradycardia with physiologic pacing on the severity of obstructive sleep apnea. BACKGROUND Apneic episodes during sleep are associated with slowing of the heart rate during apnea and tachycardia with subsequent arousal. Patients with permanent pacemakers may have reduced episodes of sleep apnea when their pacemaker rate ...

BACKGROUND Observational studies suggest that conventional right ventricular apical pacing may have a deleterious effect on left ventricular function. In this study, we examined whether biventricular pacing is superior to right ventricular apical pacing in preventing deterioration of left ventricular systolic function and cardiac remodeling in patients with bradycardia and a normal ejection fra...

To evaluate disorders of regional wall motion in patients with coronary artery disease, we developed a method to detect the boundary of the cineventriculograms with the aid of minicomputers. Each image of the left ventriculogram, taken at 60 frames/sec, was transferred to computer through a flying spot scanner and stored in the disc. The endocardial margin was automatically traced along the max...

To evaluate disorders of regional wall motion in patients with coronary artery disease, we developed a method to detect the boundary of the cineventriculograms with the aid of minicomputers. Each image of the left ventriculogram, taken at 60 frames/sec, was transferred to computer through a flying spot scanner and stored in the disc. The endocardial margin was automatically traced along the max...

BACKGROUND Has been reported that patients exhibiting prolonged paced QRS duration tend to have more serious heart disease, and the paced QRS duration can be an effective indicator of impaired left ventricular function. However, the acute and chronic hemodynamic effects of paced QRS duration and pacing sites during right ventricular (RV) pacing remain unknown. METHODS A total of 14 patients w...

INTRODUCTION Recent studies have reported the use of temporary epicardial atrial pacing as prophylaxis for postoperative atrial fibrillation (AF). The aim of this study was to assess the effect of pacing therapies for prevention of postoperative AF using meta-analysis. METHODS AND RESULTS Using a computerized MEDLINE search, eight pacing prophylaxis trials with 776 patients were included in t...

BACKGROUND Conventional right ventricular (RV) apex pacing can lead to adverse clinical outcome associated with asynchronous activation and reduced left ventricular (LV) pump function. We investigated to what extent alternate RV (septum) and LV (septum, apex) pacing sites improve LV electric activation, mechanics, hemodynamic performance, and efficiency over 4 months of pacing. METHODS AND RE...