This study examines the changes in pacing threshold and R- or P-wave amplitude during the first 30 minutes after implantation of tined and screw-in leads. The leads examined were those of 1 manufacturer (Medtronic) and consisted of 3 ventricular pacing leads (model numbers 6957 unipolar screw-in [11 patients], 6961 unipolar tined [12 patients] and 6962 bipolar tined [7 patients]) and 1 atrial l...

OBJECTIVES We evaluate the acute effects on hemodynamics of bi-atrial (BiA) pacing with the optimal atrioventricular (AV) delays, in comparison with high right atrial (HRA) pacing and coronary sinus (CS) pacing. BACKGROUND Bi-atrial pacing has been suggested as one of the alternative therapy for preventing the recurrence of atrial fibrillation (AF). There are, however, few reports on the hemo...

Introduction Patients with single-ventricle physiology palliated to a Fontan can be at risk for high-grade atrioventricular block, necessitating permanent pacemaker placement. Historically, epicardial leads have been used for these patients given the concern for clot formation within the Fontan pathway or systemic ventricle. However, epicardial pacing systems are fraught with issues, including ...

BACKGROUND Atrial septal pacing (ASP) has been shown to shorten P-wave duration (PWD) and reduce recurrence of atrial fibrillation (AF) in patients with bradyarrhythmias. However, variability of interatrial connections and atrial conduction properties may explain ASP's modest clinical benefit. The aim of this study was to assess the effect of ASP site on the duration of the paced P wave. METH...

PURPOSE To assess the effectiveness of bipolar epicardial atrial pacing using an active fixation bipolar endocardial lead implanted on the atrial surface in an experimental model. METHODS A total of ten Large White adult pigs underwent pacemaker implantation under general anesthesia. Atrial pacing and sensing parameters were obtained at the procedure, immediate postoperative period and on the...

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...

OBJECTIVE To evaluate the acute effects on haemodynamic variables of biatrial pacing in comparison with high right atrial (HRA) pacing and left lateral atrial pacing. PATIENTS AND DESIGN 23 patients were paced from the HRA site, the lateral site of the coronary sinus (CS), and both sites on two fixed atrioventricular delays (100 and 150 ms) during atrioventricular sequential pacing at 80 and ...

To the Editor: I read with interest the article on the treatment of patients who have sick sinus syndrome (SSS) with single-chamber atrial pacing by Anderson et al.1 However, their finding of the annual risk of secondor third-degree atrioventricular (AV) block of only 0.6% per year contrasts somewhat with the reported findings that abnormal AV conduction was demonstrated in 57% to 67% of patien...

BACKGROUND The blockade of angiotensin II (Ang II) formation has protective effects on cardiovascular tissue; however, the role of Ang II in atrial electrical remodeling is unknown. The purpose of this study was to investigate the effects of candesartan and captopril on atrial electrical remodeling. METHODS AND RESULTS In 24 dogs, the atrial effective refractory period (AERP) was measured bef...

The effect of atrial pacing and recording site and ventricular pacing site on assessment of conduction over the accessory pathway (AP) was examined in a group of patients with the Wolff-Parkinson-White syndrome. The importance of initial localization of the AP by recording the sequence of retrograde atrial activation during circus movement tachycardia is demonstrated. Inability to record or pac...