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. Twenty-one HF patients aged 72 ...

Biventricular (BiV) is extensively used in the treatment of congestive heart failure but so far no recommendations for optimized programming of atrioventricular-delay (AVD) settings have been proposed. Can AVD optimization be performed using a simple formula based on non-invasive doppler-echocardiography? 25 patients (ejection fraction 30+/-8%) received BiV ICDs. Doppler-echocardiographic evaluation ...

Biventricular (BIV) pacing can improve cardiac function in heart failure by altering the mechanical and electric substrates. We investigated the effect of BIV versus right ventricular (RV) pacing on the normal heart. Male New Zealand White rabbits (n=33) were divided into 3 groups: sham-operated (control), RV pacing, and BIV pacing ...

BACKGROUND: The value of myocardial perfusion SPECT (MPS) for patients with left bundle branch block (LBBB) or right ventricular apical (RVA) pacing seems reduced. The prognosis of patients with only abnormal activation related perfusion defects (AARD) due to LBBB or RVA-pacing is similar to those with a normal MPS. We ...

BACKGROUND: The right ventricular septum (RVS) and Hisian area (HA) are considered more "physiological" pacing sites than right ventricular apex (RVA). Studies comparing RVS to RVA sites have produced controversial results. There are no data about variability of electromechanical activation obtained by an approach using fluoroscopy and electrophysiological markers. This ...

BACKGROUND: The value between paced QRS duration (pQRSd) and native QRS duration (nQRSd) in paced population has not been compared. The relation between nQRSd and pQRSd remains undefined now. METHODS AND RESULTS: A total of 310 right ventricular apex (RVA) paced patients were enrolled. The correlation coefficients between nQRSd and ...

BACKGROUND: Dual-chamber pacing is believed to have an advantage over single-chamber ventricular pacing. The aim of the study was to determine whether elderly patients with implanted pacemaker for complete atrioventricular block gain significant benefit from dual-chamber (DDD) compared with single-chamber ventricular demand (VVIR). METHODS: The study was designed as a ...

AIMS: To investigate whether cardiac resynchronization therapy (CRT) by means of biventricular (BiV) pacing can improve left ventricular (LV) function, remodelling and clinical status in chronically right ventricular (RV) paced patients with mild cardiomyopathy. METHODS AND RESULTS: Thirty-six chronically (10 +/- 7 years) RV paced patients with left ventricular ejection ...

OBJECTIVE: The study objective was to compare the left ventricular (LV) dyssynchrony and torsional behavior between right ventricular apical (RVA) and right ventricular septal (RVS) pacing. METHODS: Forty-six patients with symptomatic sick sinus syndrome and preserved LV function were assigned to 2 groups: RVA (n = 23) and RVS (n ...

BACKGROUND: Right ventricular apical (RVA) pacing promotes tricuspid regurgitation (TR), electromechanical dyssynchrony, and ventricular dysfunction. We tested a novel intramyocardial bipolar lead to assess whether stimulation of the atrioventricular septum (AVS) produces synchronous ventricular activation without crossing the tricuspid valve (TV). METHODS: A lead with an active external helix and ...

OBJECTIVE: Right ventricular (RV) pacing has been associated with abnormal cardiac electrical and mechanical dyssynchrony, resulting in impaired global and regional ventricular pump function. This study aimed to characterize the relative effects of pacing site on left ventricular (LV) activation patterns and associated hemodynamic performances. METHODS: Acute pacing was performed ...

Right ventricular (RV) apical pacing induces dyssynchrony by a left bundle branch block type electrical activation sequence in the heart and may impair left ventricular (LV) function. Whether these functional changes are accompanied by changes in myocardial perfusion, oxidative metabolism and efficiency, and the relation with the induction of LV ...

BACKGROUND: In healthy people the left ventricle presents a counter-clockwise apical rotation and a clockwise basal rotation ending in late systole. In early systole (during isovolumic contraction) there is a fast and inverse rotation (counter-clockwise at the base and clockwise at the apex). This opposite rotation between apex and base ...

BACKGROUND: Whether right ventricular outflow tract (RVOT) pacing is superior to right ventricular apex (RVA) pacing in terms of ventricular synchrony, cardiac function, and remodeling in patients with normal cardiac function is still unknown. HYPOTHESIS: Right ventricular outflow tract pacing is superior to RVA pacing in patients with normal cardiac ...

BACKGROUND: A properly placed stimulus on the T-wave during ventricular repolarization can result in ventricular fibrillation (VF). Initiation of VF with pacing on T-wave is a rare event with a few reported cases in the literature. We present a unique case of induced VF attributed to a pacing stimulus on ...

BACKGROUND: Transcoronary pacing for the treatment of bradycardia during percutaneous coronary intervention (PCI) is not well established, but may be a useful technique in interventional cardiology. We developed a porcine model to examine the feasibility and efficacy of transcoronary pacing during PCI. METHODS AND RESULTS: Eight pigs under general anesthesia ...

BACKGROUND: Previous large animal heart failure models led to inhomogeneous results. Therefore, we developed a novel model combining rapid pacing with forced ventricular desynchronization. METHODS: Heart failure was induced in 20 pigs during a pacing period of 21 days. Group A (n = 10) received one right ventricular lead (220 ...

Right ventricular apical (RVA) pacing may induce mechanical dyssynchrony. However, its impact on patients with normal ejection fraction (EF) is not fully understood. This study examined the prevalence and predictors of RVA pacing-induced systolic dyssynchrony by real-time three-dimensional echocardiography (RT3DE), and evaluated its impact on left ventricular (LV) function. Ninety-three ...

OBJECTIVES: We sought to evaluate the impact of the left ventricular (LV) pacing site on hemodynamic response to cardiac resynchronization therapy (CRT). BACKGROUND: CRT reduces morbidity and mortality in heart failure patients. However, 20% to 40% of eligible patients may not fully benefit from CRT device implantation. We hypothesized that ...

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 ...

The ventricular sense response (VSR) algorithm enforces biventricular pacing on ventricular sensing to maximize biventricular pacing in patients with atrial fibrillation. This report describes a case of recurrent ventricular tachycardia that may be facilitated by this enforced pacing algorithm.

Pediatric patients with complete heart block (CHB) often require pacemaker therapy. Adult studies have shown chronic right ventricular pacemaker therapy may be associated with decreased echocardiographic parameters and increased brain natriuretic peptide (BNP) values. The goal of this study was to determine if there are echocardiographic or BNP changes in ...

Right ventricular apical (RVA) stimulation, although beneficial in the treatment of symptomatic bradycardia, has proven detrimental in a substantial percentage of pacemaker recipients, leading to iatrogenic deterioration of left ventricular structure and function. Alternative right ventricular pacing sites appeared advantageous but their superiority has not been proven. Biventricular stimulation is ...

Biventricular pacing is an efficient treatment to improve symptoms and clinical outcome in patients with drug-refractory heart failure, low left ventricular ejection fraction and wide QRS. The basis of the treatment is the permanent delivery of biventricular pacing. During the follow-up of biventricular devices the assessment of permanent biventricular capture ...

The pacing site has been shown to influence functional improvement with cardiac resynchronization therapy. We evaluated the effects of the pacing site on left ventricular (LV) function in an animal model. Equilibrium radionuclide angiography was acquired in sinus rhythm (NSR) and with ventricular pacing, from three pacing sites in seven ...

AIMS: The immediate effects of electric remodelling on the left ventricular (LV) function by dual-chamber pacemakers remain unknown. The purpose of our study was to assess the interaction between heart rates and right ventricular pacing (VP) on LV contractility and diastolic function. METHOD AND RESULTS: Twenty-five patients with dual-chamber pacemakers ...

OBJECTIVE: To compare left ventricular synchronization and systolic performance with transvenous pacing of the right ventricular apex (RVA), left ventricular free wall (LVF) or simultaneous pacing of the RVA and LVF (BiV). ANIMALS, MATERIALS AND METHODS: Seven canine patients with complete heart block. Prospective study evaluating effect of pacing site. ...

The goal of this work was to investigate the hemodynamic effects of simultaneous left ventricular (LV) pacing site (LVPS) and interventricular pacing delay (VVD) variation with biventricular pacing (BiVP) during acute LV failure. Simultaneously varying LVPS and VVD with BiVP has been shown to improve hemodynamics during acute right ventricular ...

In pulmonary arterial hypertension (PAH), duration of myofiber shortening is prolonged in the right ventricular (RV) free wall (RVfw) compared with that in the interventricular septum and left ventricular free wall. This interventricular mechanical asynchrony eventually leads to right heart failure. We investigated by computer simulation whether, in PAH, early ...

BACKGROUND: The detrimental effects of right ventricular (RV) apical pacing on left ventricular function has driven interest in alternative pacing sites and in particular the mid RV septum and RV outflow tract (RVOT). RV septal lead positioning can be successfully achieved with a specifically shaped stylet and confirmed by the ...

BACKGROUND: The increasing data suggest an association between chronic right ventricular (RV) and left ventricular (LV) dysfunction. We sought to determine the effect of temporary interruption of long-term RV pacing on LV function and mechanical dyssynchrony in children and young adults with complete heart block. METHODS: Twelve patients aged 20.0 ...

Inadvertent placement of a pacemaker lead in the left ventricle (LV) is a rare complication of pacing. We describe a case of inadvertent LV pacing where the ventricular lead traversed the mediastinum and accessed the heart through the posterior wall of the left atrium. Both transesophageal echo and venography were ...

A 65-year-old man with frequent premature ventricular contractions (PVCs) underwent electrophysiological testing. Although an excellent pace map was obtained from the right coronary cusp (RCC), radiofrequency ablation at that site interrupted the PVCs transiently. Successful ablation was achieved in the left coronary cusp with earlier local ventricular activation during the ...

BACKGROUND: Therapeutic hypothermia (TH, 30 degrees C) protects the brain from hypoxic injury. However, TH may potentiate the occurrence of lethal ventricular fibrillation (VF), although the mechanism remains unclear. The present study explored the hypothesis that TH enhances wavebreaks during VF and S(1) pacing, facilitates pacing-induced spatially discordant alternans (SDA), ...

For infants with congenital complete atrioventricular block (CCAVB), the choice of pacing modalities is limited. Due to their size and surgical limitations, neonates typically start with an epicardial right ventricular pacing system, then upgrade to right-sided dual-chamber pacing once appropriate size is achieved. These modes are generally well tolerated. However, ...

We describe effects of pacing lead position and cardiac microanatomy on electrical pacing parameters. Passive fixation transvenous pacing leads were implanted in anterior interventricular veins in isolated swine hearts (n = 6). Electrical pacing parameters were measured in 3 implant positions (5 implant sites each): touching myocardial side of venous ...

We report the technique of transatrial delivery of the Medtronic 3830 SelectSecure lead (Medtronic Inc., Minneapolis, MN, USA) for right ventricular endocardial pacing in two young adults with congenital heart disease who had multiple pacing lead failures and superior vena cava occlusion. The deflectable catheter delivery system used to position ...

The right ventricular apex (RVA) has been the elective site for placing endocardial pacing leads since 1959 when Furman described the use of the transvenous route for pacemaker implantation. This site was used because it is easily accessible, readily identified and associated with a stable position and reliable chronic pacing ...

AIM: The study aimed to determine if right ventricular apical pacing is associated with adverse change in atrial substrate compared with right ventricular septal pacing. METHODS: Patients with septal leads and dual-chamber devices with more than 3 months of follow-up and 70% or higher cumulative percentage of ventricular pacing were ...

: To test an alternative to catheter and open-heart techniques, by documenting the feasibility of implanting an unmodified mechanical aortic valve (AoV) in the off pump, beating heart using the universal cardiac introducer (UCI) attached to the left ventricular (LV) apex. : In six pigs, the LV apex was exposed ...

BACKGROUND: Intracardiac impedance (ICZ) has been known to reflect contractile capacity of the heart, and a strong relationship has been documented between stroke volume and ICZ. In this pilot study, conducted in heart failure patients during implantation of a biventricular device, we investigated acute changes in multiple vector ICZ signals ...

Early electrocardiographic diagnosis of acute coronary ischaemia on the paced electrocardiogram is possible [H. Kilic, E. Atalar, N. Ozer, K. Ovunc, S. Aksoyek, F. Ozmen, R. Akdemir. Early electrocardiographic diagnosis of acute coronary ischaemia on the paced electrocardiogram. Int J Cardiol 2008; 130: 14-18.] and could be helpful in an ...

Cardiac pacing is the only effective treatment for patients with sick sinus syndrome and atrioventricular conduction disorders. In cardiac pacing, the endocardial pacing lead is typically positioned at the right ventricular (RV) apex. At the same time, there is increasing indirect evidence, derived from large pacing mode selection trials and ...

Para-Hisian pacing at high output simultaneously captures the His bundle or proximal right bundle, as well as the adjacent ventricular myocardium. At lower output, direct His-bundle, or right-bundle, capture is lost which causes an increase in the stimulus to atrium interval. We describe a case with an increment of 68 ...

BACKGROUND: Optimal right ventricular (RV) pacing site in patients referred for permanent cardiac pacing remains controversial. A prospective randomized trial was done to compare long-term effect of permanent RV apex (RVA) vs RV outflow tract (RVOT) pacing on the all-cause and cardiovascular mortality. METHODS AND RESULTS: A total of 122 ...

BACKGROUND: Right ventricular septal (RVS) pacing is an alternative to right ventricular apical (RVA) pacing, but there is limited information about its influence on long-term left ventricular (LV) synchrony and function. METHODS AND RESULTS: A total of 55 patients undergoing dual-chamber pacemaker implantation with normal QRS duration and preserved LV ...

BACKGROUND: We investigated the benefits of the more physiological activation achieved by left ventricular (LV) endocardial pacing (ENDO) as compared with conventional epicardial (EPI) LV pacing in cardiac resynchronization therapy. METHODS AND RESULTS: In 8 anesthetized dogs with experimental left bundle-branch block, pacing leads were positioned in the right atrium, ...

AIMS: Right ventricular pacing increases the risk of persistent atrial fibrillation (AF) in the long term. The effects of right ventricular pacing on paroxysmal AF (PAF) are unknown. The aim was to examine the effect of right ventricular pacing on AF burden (AFB) in patients with symptomatic drug-resistant PAF. Pooled ...

BACKGROUND: The VDD/R pacing is accepted as an alternative to DDD/R pacing in patients with atrioventricular conduction block (AVB) and intact sinus node function. AIM: To determine the relationship between parameters obtained during assessment of the patient for the implantation procedure, using electrocardiographic (ECG) and echocardiographic (ECHO) data, and the ...

Atrioventricular nodal (AVN) ablation with concomitant pacemaker implantation is one of the strategies that reduce symptoms in patients with atrial fibrillation (AF). However, the long-term adverse effects of right ventricular (RV) apical pacing have led to the search for alternating sites of pacing. Biventricular pacing produces a significant improvement in ...