The purpose of this study was to investigate the acute effect of right ventricular outflow tract (RVOT) pacing and right ventricular apex (RVA) pacing on synchronous ventricular activation and coronary flow dynamics. We enrolled 20 consecutive patients who underwent electrophysiologic study. Echocardiographic study including two-dimensional tissue tracking imaging and Doppler ...

Permanent biventricular pacing benefits patients with heart failure and interventricular conduction delay, but the importance of pacing with and without optimization in patients at risk of low cardiac output after cardiac surgery is unknown. We hypothesized that pacing parameters independently affect cardiac output. Accordingly, we analyzed aortic flow measured with ...

To investigate differences in latency intervals during right ventricular (RV) pacing and left ventricular (LV) pacing from the (postero-)lateral cardiac vein in cardiac resynchronization therapy (CRT) patients and their relationship to echo-optimized interventricular (V-V) intervals and paced QRS morphology. We recorded digital 12-lead electrocardiograms in 40 CRT patients during RV, ...

The objective of this study was to compare long-term clinical effects of biventricular pacing with isolated left ventricular pacing. Forty consecutive patients with idiopathic dilated cardiomyopathy and indication for cardiac resynchronization therapy were randomized to biventricular or isolated left ventricular pacing. Clinical and echocardiographic parameters were studied regularly prior to ...

This study used multi-detector row CT (MDCT) to evaluate the regional geometric parameters of left ventricle (LV) in patients and dogs after right ventricular apical (RVA) pacing. First, we measured and compared the global and regional wall motion parameters derived from MDCT images between three patients post RVA pacing and ...

The current report describes a manifestation of linking phenomenon in DDD pacemaker recipients: impairment of atrioventricular (AV) conduction and ensuing unnecessary right ventricular (RV) pacing. Three patients with second-degree AV block and sudden impairment of native AV conduction following pacemaker implantation are presented. Loss of native AV conduction was considered ...

Transvenous pacing leads are regularly placed in the right ventricular (RV) apex. Pediatric patients can develop myopathic changes after long-term RV apical pacing. Left ventricular (LV) mechanical dyssynchrony, estimated with echocardiography, may explain the acute decrease in LV function and long-term histopathologic changes. Ts-4w is an established echocardiographic measurement of ...

Temporary epicardial pacing wires are commonly placed during pediatric cardiac surgery. Data are sparse on postoperative pacing in this population. The objective of this study was to determine the frequency of use and identify predictors for the use of temporary epicardial pacing wires. Perioperative data were prospectively collected on all ...

A 37-year-old woman with idiopathic premature ventricular contractions (PVCs), exhibiting a right bundle branch block and inferior axis QRS morphology, underwent electrophysiological testing. The earliest ventricular activation with an isolated prepotential was observed within the great cardiac vein during the PVCs. Pacing from this site with an output of 10 ...

While successful termination by pacing of organized atrial tachycardias has been observed in patients, rapid pacing of AF can induce a local capture of the atrial tissue but in general no termination. The purpose of this study was to perform a systematic evaluation of the ability to capture AF by ...

The authors investigated acoustic cardiography, the digital analysis of electrocardiogram (ECG) and heart sounds, to detect phrenic nerve stimulation (PNS) and assess its hemodynamic significance. They studied 42 patients and induced 46 instances of PNS induced through cardiac pacing at various locations in the heart. These 46 instances of PNS ...

Pacing and entrainment maneuvers are essential for establishing the mechanism of supraventricular tachycardia (SVT), but may fail to do so if the SVT terminates or if pacing results in atrioventricular (AV) dissociation as opposed to entrainment of the arrhythmia. We present an unusual case of typical AV nodal reentrant tachycardia ...

Optimal left ventricular (LV) lead position improves the response to cardiac resynchronization therapy (CRT). However, in some patients it is not possible to position the LV lead at an optimal pacing site. The aim of this study was to determine whether optimization of the pacing settings atrioventricular delay (AVD) and ...

Bidirectional block of the cavo-tricuspid isthmus (CTI) is a widely accepted endpoint for typical atrial flutter ablation, but its evaluation may be difficult, especially in the postero-anterior (clockwise) direction. The main goal was to evaluate pacing at the septal edge of the ablation line as an indicator of clockwise CTI ...

The present case illustrates that in patients with right ventricular (RV) failure and right bundle branch block it is possible to resynchronize the RV without further worsening RV or left ventricular (LV) pump function, even in cases with various degrees of atrioventricular block. The acute response to different pacing configurations ...

The need for pacing support in typical ICD patients is unknown. This study sought to determine whether atrial pacing with ventricular backup pacing is equivalent to ventricular backup pacing only in implantable cardioverter-defibrillator (ICD) patients. We randomized 1,030 patients from 84 sites with indications for ICDs, with sinus rhythm, and ...

The CAPTURE study evaluated the accuracy of automated atrial and right ventricular (RV) threshold algorithms. Modern pacemakers include many added features designed to improve the ease of patient follow-up, as well as algorithms to reduce pacing outputs and/or reduce the atrial or ventricular pacing percentages, thus improving longevity. Automated atrial ...

A case of accidental triggering of an intra-aortic balloon pump during systole is presented. The patient had a cardiac resynchronization therapy device in place preoperatively for heart failure. A temporary epicardial atrial pacing wire was used during separation from cardiopulmonary bypass for rate control. An intra-aortic balloon pump was necessary ...

Localization of the initial site of cardiac ectopic activity has direct clinical benefits for treating focal cardiac arrhythmias. The aim of the present study is to experimentally evaluate the performance of the equivalent moving dipole technique on noninvasively localizing the origin of the cardiac ectopic activity from the recorded body ...

Right ventricular (RV) apical pacing may result in ventricular dyssynchrony, which is associated with functional and morphological changes in the left ventricle (LV). Our aim is to assess contraction and hypertrophy-related protein expression changes in the LV after RV apical pacing. Six dogs underwent dual chamber pacemaker (DDD) implantation and ...

Increased matrix metalloproteinase (MMP) abundance occurs with adverse left ventricular (LV) remodeling in a number of cardiac disease states, including those induced by long-standing arrhythmias. However, whether regionally contained aberrant electrical activation of the LV, with consequent dyskinesia, alters interstitial MMP activation remained unknown. Electrical activation of the LV of ...

Biventricular pacing (BiVP) can increase cardiac output (CO) during acute failure of the left ventricle (LV) after cardiac surgery. This CO benefit is maximized by adjustment of atrioventricular (AVD) and interventricular (VVD) pacing delays. Real-time CO calculation could facilitate this optimization. Accordingly, we compared real-time automated analysis (AA) of CO ...

Precordial percussion is a technique by which a manual force is applied repeatedly to the chest of a patient experiencing an unstable bradycardic or asystolic rhythm. The force is used not to defibrillate the myocardium as is the case with the "precordial thump" in pulseless ventricular tachycardia/ventricular fibrillation but rather ...

Patients who are entirely dependent on ventricular pacing are typically at the mercy of a single ventricular lead and pacemaker output in order to provide physiologic support. This study presents a number of high-risk cases (two of which previously exhibited failure with standard pacing) in which ventricular pacing redundancy (VPR) ...

A case of inappropriate atrial pacing in a patient with a pacemaker programmed with Managed Ventricular Pacing (MVP) mode, a proprietary algorithm in Medtronic devices, is presented. The patient was an 84-year-old woman who presented in sinus rhythm with complete atrioventricular block. A dual-chamber pacemaker was implanted and programmed to ...

Prolonged right ventricular (RV) apical pacing is associated with progressive left ventricular dysfunction due to dysynchronous ventricular activation and contraction. RV septal pacing allows a narrower QRS compared to RV apical pacing, which might reflect a more physiological and synchronous ventricular activation. Previous clinical studies, which did not consistently achieve ...

BACKGROUND: The optimal right ventricular pacing site remains controversial. The aim of this study was to assess how acute right ventricular outflow tract (RVOT) pacing affects global left ventricular function and intraventricular dyssynchrony of the left ventricle. METHODS: Thirty-six patients with sick sinus syndrome and intact intrinsic atrioventricular conduction were ...

Right ventricular pacing increases the risk of heart failure in adults with structural heart disease. The impact of prolonged right ventricular pacing in adults without structural heart disease is not fully characterized and may depend on interactions of pacing with abnormal substrate predisposing to ventricular dysfunction. We assessed the effect ...

AIMS: Right ventricular apical pacing can have deleterious effects and the His bundle has been widely reported to be an alternative site. This paper presents our experience with permanent His-bundle pacing (HBP). METHODS AND RESULTS: Patients referred for pacemaker implants (regardless of block type) were screened to determine if temporary ...

Ventricular pacing causes early myocardial shortening at the pacing site and pre-stretch at the opposing ventricular wall. This contraction pattern is energetically inefficient and may lead to decreased cardiac function. This study was designed to describe the acute effects of right ventricular apical (RV(a)) pacing on dyssynchrony and systolic function ...

Chronic right ventricular apical pacing (RVAP) has been associated with negative hemodynamic and clinical effects. The aim of the present study was to compare RVAP with right ventricular septal pacing (RVSP) in terms of echocardiographic features and clinical outcomes. A total of 93 patients without structural heart disease and with ...

Brief periods of ventricular pacing during the early reperfusion phase (pacing-induced postconditioning, PPC) have been shown to reduce infarct size as measured after 2 h of reperfusion. In this study, we investigated (1) whether PPC leads to maintained reduction in infarct size, (2) whether abnormal mechanical load due to asynchronous ...

OBJECTIVES: Determine if temporary artificial cardiac pacing can be accomplished from transesophageal or transgastric pacing sites. ANIMALS, MATERIALS AND METHODS: Nine purpose bred Beagle dogs had a multipolar electrophysiology pacing catheter inserted transnasally and advanced into the distal esophagus or stomach under general anesthesia. Artificial atrial pacing was attempted using ...

BACKGROUND AND PURPOSE: Permanent right ventricular apical pacing can result in heart failure due to ventricular mechanical dyssynchrony. The purpose of the study was to define differences in left ventricular dyssynchrony between high septal pacing and apical pacing using tissue Doppler imaging (TDI) and two-dimensional (2D) speckle-tracking echocardiography (STE). METHODS: ...

The benefits obtained with cardiac resynchronization therapy are directly related to the occurrence of continuous biventricular pacing. We report a case of intermittent loss of biventricular pacing due to ventricular oversensing that worsened the functional status of the patient.

The effect of right ventricular (RV) pacing on tricuspid regurgitation (TR) is debatable and is presumed to be related to an interference with valve closure by the electrode. The aim of the study was to determine the impact of pacing per se on TR grade. The study group included 23 ...

BACKGROUND: Worsening in clinical and cardiac status has been noted after chronic right ventricular pacing, but it is uncertain whether atriobiventricular (BiVP) is preferable to atrio-right ventricular pacing (RVP). Conventional versus Multisite Pacing for BradyArrhythmia Therapy study (COMBAT) sought to compare BiVP versus RVP in patients with symptomatic heart failure ...

OBJECTIVE: The aim of this study was to compare the cross-follow-up results in DDD or AAISafeR mode and to describe the safety and effectiveness of this pacing mode. METHODS: The Symphony 2450/2550 cardiac pacemakers were implanted in 30 patients with sick sinus syndrome between February 2006 and September 2006. They ...

Biventricular (BiV) pacing or cardiac resynchronization therapy (CRT) is an established therapy for heart failure in adults. In children, cardiac dyssynchrony occurs most commonly following repair of congenital heart disease (CHD) where multisite pacing has been shown to improve both hemodynamics and ventricular function. Determining which patient types would specifically ...

Infants and children with congenital aortic stenosis and coarctation of the aorta can be treated by catheter intervention. There are several pharmacological and mechanical techniques described to overcome the balloon movement; none, however, have proved entirely satisfactory. An alternative method to achieve balloon stability is the use of rapid ventricular ...

BACKGROUND: Randomized trials have demonstrated benefits of biventricular (BiV) pacing in patients with advanced heart failure, intraventricular conduction delay, and atrial fibrillation (AF) post-atrioventricular (AV) node ablation. The AV Node Ablation with CLS and CRT Pacing Therapies for Treatment of AF trial (AVAIL CLS/CRT) was designed to demonstrate superiority of ...

Heart failure leads to gross cardiac structural changes. While cardiac resynchronization therapy (CRT) is a recognized treatment for restoring synchronous activation, it is not clear how changes in cardiac shape and size affect the electrical pacing therapy. This study used a human heart computer model which incorporated anatomical structures such ...

Renin-angiotensin system (RAS) is activated in the fibrillating atria. Angiotensin-(1-7) [Ang-(1-7)] counterbalances the actions of angiotensin II (Ang II). To investigate the effects of Ang-(1-7) on the long-term atrial tachycardia-induced atrial fibrosis and atrial fibrillation (AF) vulnerability, eighteen dogs were assigned to sham group, paced group, or paced+Ang-(1-7) group, 6 ...

Introduction: Infants and children with congenital aortic stenosis and coarctation of the aorta can be treated by catheter intervention. There are several pharmacological and mechanical techniques described to overcome the balloon movement; none, however, have proved entirely satisfactory. An alternative method to achieve balloon stability is the use of rapid ...

OBJECTIVES: Little is known about coronary sinus lead performance in patients with cardiac resynchronization therapy devices. We evaluated the impact of clinical and technical parameters on coronary sinus lead performance over long-term follow-up. METHODS: From February 1999 to July 2004, 235 patients (181 men; mean age, 68 +/- 9 years; ...

Sustained atrial fibrillation (AF) was induced by atrial burst pacing, and monophasic action potentials (MAPs) were recorded. MAP alternans was observed at a cycle length (CL) of 167.5 ± 28.2 msec before burst pacing and 201.3 ± 40.2 msec after burst pacing. AF > 5 minutes duration was induced in ...

AIMS: Managed ventricular pacing (MVP) and Search AV+ are representative dual-chamber pacing algorithms for minimizing ventricular pacing (VP). This randomized, crossover study aimed to examine the difference in ability to reduce percentage of VP (%VP) between these two algorithms. METHODS AND RESULTS: Symptomatic bradyarrhythmia patients implanted with a pacemaker equipped ...

AIMS: Biventricular pacing (BiP) is an effective treatment in systolic heart failure (HF) patients with prolonged QRS. However, approximately 35% of the patients receiving BiP are classified as non-responders. The aim of this study is to evaluate the acute effects of VV-optimization on systolic heart function. METHODS: Twenty-one HF patients ...

Cardiac hypertrophy develops in response to increases in afterload, most commonly as the result of hypertension. When left untreated, cardiac hypertrophy commonly progresses to heart failure, one of the leading causes of death in the US. A number of studies have shown that reversing cardiac hypertrophy can decrease the progression ...

BACKGROUND: Evaluation of repolarization during sequentional biventricular pacing. METHODS: Patients with biventricular devices, and left ventricular leads placed to the basal part of lateral left ventricular wall were enrolled. QRS, QTc, JTc, and corrected Tpeak-Tend intervals were compared during sequentional biventricular, left ventricular, and right ventricular pacing. RESULTS: Five patients ...