Search Results
Results 451 - 500 of 2019
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Topilski Ian - - 2006
Various treatment modalities have been introduced to reduce the subaortic pressure gradient in patients with obstructive hypertrophic cardiomyopathy, including pacemaker insertion. Complete ventricular capture during pacing is essential and requires optimization of the atrioventricular interval (AVI). In this study, a protocol using echocardiographic examination assessing the changes in the left ...
Roberts Ashley D - - 2006
BACKGROUND: Pacing in children with congenital heart disease often requires alternate approaches to standard transvenous pacing. The surgical approach used to implant the pacemaker leads has been shown to impact lead survival. There is a paucity of pediatric literature describing the experience using a left thoracotomy approach. OBJECTIVES: To report ...
Gross Gil J - - 2006
Bradycardic states are associated with myocardial electrical remodeling predisposing to potentially lethal ventricular tachydysrhythmias. We used a novel model of complete heart block (CHB) in the rabbit to test the hypothesis that ventricular activation rate is the primary determinant of early bradycardic electrical remodeling. Chronic endocardial right ventricular demand (VVI) ...
Bai Rong - - 2006
Intermittent retrograde conduction over an accessory pathway (AP) is an uncommon phenomenon. We report a case of Wolff-Parkinson-White syndrome in which retrograde conduction of the bypass tract was present only during right ventricular (RV) outflow tract and left ventricular pacing or during RV inflow tract pacing with a fast pacing ...
Occhetta Eraldo - - 2006
OBJECTIVES: The aim of our study was to evaluate the feasibility, the safety, and hemodynamic improvements induced by permanent para-Hisian pacing in patients with chronic atrial fibrillation and narrow QRS who underwent atrioventricular (AV) node ablation. BACKGROUND: Right ventricular apical pacing, inducing asynchronous ventricular contraction, may impair cardiac function; permanent ...
Kindermann Michael - - 2006
OBJECTIVES: The Homburg Biventricular Pacing Evaluation (HOBIPACE) is the first randomized controlled study that compares the biventricular (BV) pacing approach with conventional right ventricular (RV) pacing in patients with left ventricular (LV) dysfunction and a standard indication for antibradycardia pacing in the ventricle. BACKGROUND: In patients with LV dysfunction and ...
Laske Timothy G - - 2006
BACKGROUND: Direct His bundle pacing results in rapid synchronous ventricular activation. However, clinical experiences with such pacing have been associated with long procedure times and compromised pacing and sensing performance. METHODS: We evaluated myocardial activation sequences (AS) for pacing of the His bundle and peri-His region and assessed acute pacing ...
van Beek Eugène - - 2006
Three patients with heart failure after chronic right ventricular apical pacing were treated with resynchronization. Biventricular pacing was used for two patients, and the other was treated with left univentricular pacing. In all patients, we observed a dramatic improvement of left ventricular dimension, function, and clinical state. We conclude that ...
Yeh Hung-I - - 2006
OBJECTIVE: We studied the response of the superior vena cava (SVC) myocardial sleeve to atrial fibrillation (AF). METHODS AND RESULTS: We examined adult male dogs without pacing (N=6) and after rapid atrial pacing (600 bpm) for 2 weeks (P2w; N=5) and 6-8 weeks (P6-8w; N=5). After pacing, the sleeve was ...
Tomioka Hideyuki - - 2006
OBJECTIVE: To investigate the effect of biventricular and high septal pacing on the normal contraction sequence of the helical ventricular myocardial band, and its impact on left ventricular function. METHODS: Ten pigs (25-68 kg) underwent analysis of percent segmental shortening (SS%) by sonomicrometry, with crystals placed along the fiber orientation ...
Liakopoulos Oliver J - - 2006
OBJECTIVE: To determine the effects of ventricular pacing on the normal contraction sequence of the helical ventricular myocardial band, and its' impact on left ventricular function. METHODS: Ten pigs (25-68 kg) underwent analysis of percent segmental shortening (%SS) by sonomicrometry, with crystals placed along the fiber orientation of the ascending ...
Hirashiki Akihiro - - 2006
OBJECTIVES: The relation between the occurrence of pacing-induced mechanical alternans and prognosis in patients with mild-to-moderate idiopathic dilated cardiomyopathy (IDCM) in sinus rhythm was investigated prospectively. The myocardial expression of genes for Ca2+-handling proteins in such patients was also examined. BACKGROUND: Mechanical alternans occurs in some patients with severe heart ...
Wu Li-qun - - 2006
BACKGROUND: Nominal atrioventricular (AV) interval in dual chamber pacemaker (DDD) is not the best AV delay in the majority of patients with atrioventricular block. To find a simple method for optimizing AV delay adjustment, we assessed surface electrocardiography (ECG) for optimizing AV delay during dual chamber pacing. METHODS: DDD pacemakers ...
Olshansky Brian - - 2006
BACKGROUND: Unnecessary right ventricular (RV) pacing in patients with implantable cardioverter defibrillators (ICD) may adversely affect heart failure morbidity and total mortality. Inhibition of Unnecessary RV Pacing with AV Search Hysteresis in ICDs (INTRINSIC RV) is a prospective, multicenter, randomized trial evaluating outcomes in ICD recipients programmed to single-chamber pacing ...
Manolis Antonis S - - 2006
BACKGROUND: The purpose of this article is to critically review the data accumulated to date from studies evaluating the hemodynamic and clinical effects of right ventricular apical pacing during conventional permanent cardiac pacing. The data from studies comparing the effects of right ventricular apical pacing and alternate site ventricular pacing ...
Ravi Krishna - - 2006
Low-energy defibrillation is very desirable in cardiac rhythm management. We previously reported that ventricular fibrillation (VF) can be synchronized with a novel synchronized pacing technique (SyncP) using low-energy pacing pulses. This study sought to create a line of block during VF using SyncP. SyncP was performed in six isolated rabbit ...
Berberian George - - 2006
OBJECTIVE: Previous work from our laboratory has demonstrated that optimization of biventricular pacing is load dependent. Cardiac output was maximized with a ventricular-ventricular delay of +40 milliseconds (right ventricle-first pacing) during right ventricular pressure overload and with a ventricular-ventricular delay of -40 milliseconds (left ventricle-first pacing) during right ventricular volume ...
Victor Frederic - - 2006
OBJECTIVES: This study compared chronic right ventricular (RV) pacing at the septum versus apex. BACKGROUND: Chronic RV apical pacing may be detrimental to ventricular function. This randomized, pilot study examined whether, compared with apical, permanent septal pacing preserves cardiac function. METHODS: Ablation of the atrioventricular junction for permanent AF, followed ...
Martinez Claudia - - 2006
Since the first implantation of a cardiac pacemaker in the second half of the 20th century, there have been evolutionary and revolutionary advances in the technology developed for patients with heart rhythm disturbances. These advances, however, have instead failed to demonstrate that mimicry of physiology by a pacing system would ...
Bian Weining - - 2006
This study examines how a zigzag pattern of conduction, a form of structural heterogeneity frequently found in old or diseased hearts, affects the vulnerability to reentry during rapid pacing. A central rectangular island (8x4 mm) containing a predefined zigzag pattern was created in cultured isotropic monolayers of neonatal rat ventricular ...
Rubaj Andrzej - - 2006
Immune system activation and oxidative stress are involved in the pathogenesis of heart failure (HF). We aimed to test the hypothesis that upgrading from right ventricular pacing (RVp) to biventricular pacing (BiVp) can counteract these phenomena. 28 HF patients, with BiVp were switched to RVp for one week, and then ...
Celiker Alpay - - 2006
The dual-chamber pacing systems allow for AV synchrony, but generally require the placement of two separate transvenous leads. Single-lead atrioventricular synchronous pacing system (VDD) using single-pass leads has been accepted as therapeutic alternative for atrioventricular block with normal sinus node function. The aim of this study is to evaluate clinical ...
Yeh Kuan-Hung - - 2006
This case study describes a patient with complete heart block inadvertently paced from the left ventricular posterior wall due to perforation of interventricular septum by a temporary pacing catheter. This is a rare but potentially fatal complication of pacing. The frontal chest radiograph neither identified abnormalities nor could determine the ...
Komsuoglu Baki - - 2006
We report a case of hypertrophic obstructive cardiomyopathy (HOCM) that was markedly improved by biventricular pacing. A 55-year-old woman with HOCM presented with palpitation and presyncope. Electrophysiologic study revealed an atrioventricular nodal reentrant tachycardia. After radiofrequency catheter ablation, a Mobitz type II atrioventricular block developed and a permanent pacemaker implantation ...
Sweeney Michael O - - 2006
Clinical trials in patients with pacemakers for sinus node dysfunction or atrioventricular block (AVB) and implantable cardioverter-defibrillators provide increasing evidence showing that desynchronization of ventricular electrical activation and contraction, induced by conventional right ventricular apex (RVA) pacing, is a serious threat for long-term cardiac morbidity and mortality. The risk of ...
Israel Carsten W - - 2006
Asynchronous ventricular pacing has been shown to increase the risk of development of atrial fibrillation (AF) because of various mechanisms: retrograde atrioventricular (AV) conduction with increase in atrial pressure causing acute atrial stretch and reverse flow in the pulmonary veins, mitral regurgitation, reduced coronary blood flow, adverse neuroendocrine reactions, etc. ...
Hsieh Ming-Jer - - 2006
In the past, patients requiring permanent pacing with difficult right ventricular (RV) access were usually subjected to epicardial pacing by a surgical approach. This report describes a young patient with univentricular physiology following repeated palliative surgery for complex congenital heart disease. The patient had symptomatic complete heart block and a ...
Fröhlig Gerd - - 2006
AIMS: To examine the performance of AAIsafeR2, a new pacing mode to minimize the cumulative proportion of ventricular pacing in patients who do not need regular ventricular support. METHODS AND RESULTS: The safety of AAIsafeR2 was examined in 123 recipients (73 +/- 12 years old, 51% men) of dual chamber ...
McGavigan Andrew D - - 2006
PURPOSE OF REVIEW: The traditional site for ventricular pacing, the right ventricular apex, produces an abnormal pattern of ventricular depolarization and there is growing evidence that pacing from this site is associated with adverse functional and structural changes in the left ventricle. This is manifest clinically as an increased morbidity ...
Liu Z - - 2006
This paper presents a novel electrocardiographic inverse approach for imaging the 3-D ventricular activation sequence based on the modeling and estimation of the equivalent current density throughout the entire myocardial volume. The spatio-temporal coherence of the ventricular excitation process is utilized to derive the activation time from the estimated time ...
Etienne Yves - - 2006
Cardiac resynchronisation therapy (CRT) using biventricular (BIV) pacing has proved its effectiveness to correct myocardial asynchrony and improve clinical status of patients with severe congestive heart failure (CHF) and widened QRS. Despite a different effect on left ventricular electrical dispersion, left univentricular (LV) pacing is able to achieve the same ...
Zhong Jing-quan - - 2006
BACKGROUND: It was the aim of this study to investigate the variation in metalloproteinase and tissue inhibitor of metalloproteinase (TIMP) connexin levels during tachycardia-induced cardiomyopathy (TIC). METHODS: Canine models of TIC were established by rapid right atrial pacing at 350-400 beats per min for 8 weeks in 11 dogs, with ...
Watanabe Kuniyoshi - - 2006
The MCMS-0102 cardiac pacemaker for rapid ventricular pacing to induce heart failure in animals has been improved in terms of miniaturization and performance. To determine the performance of the new MCMS-0102, six devices were implanted in beagle dogs, and two of these devices were reimplanted for continued pacing in a ...
Tang Liang - - 2006
Ventricular fibrillation (VF) can be synchronized with a novel synchronized pacing technique (SyncP) using low-energy pacing pulses, which causes pace termination of VF. Synchronized pacing (SyncP) is defined as optical recording guided real-time detection and stimulation of spatiotemporal excitable gaps. In this paper, we investigate the effect of post-shock SyncP ...
Zanon Francesco - - 2006
INTRODUCTION: Much clinical evidence has shown that right ventricular (RV) apical pacing is detrimental to left ventricular function. Preservation of the use of the His-Purkinje (H-P) system may be ideal in heart block that is restricted to the AV node, but may be of no benefit when H-P disease exists. ...
Budeus Marco - - 2006
BACKGROUND: Many patients with ICD receive different antiarrhythmic drugs (e.g. sotalol, amiodarone, beta-blockers) because of ventricular or atrial tachycardias. These drugs can cause AV-block or chronotropic incompetence resulting in a higher percentage of ventricular pacing. METHODS: We analyzed in a retrospective study the impact of DDD(R) versus VVI(R) mode on ...
Hsiao Hsiang-Chiang - - 2006
BACKGROUND: Abnormal activation of the ventricles via right ventricular apical pacing deteriorates cardiac function, which may explain the increased mortality of patients with congestive heart failure receiving permanent pacemakers. We hypothesized that pacing at alternative sites may cause less detrimental effects on the cardiac function. METHODS: Five symptomatic patients with ...
Höijer Carl J - - 2006
AIMS: To investigate whether patients with previously implanted conventional pacemakers and severe heart failure benefit from an upgrade to a biventricular system. METHODS AND RESULTS: Study inclusion criteria were New York Heart Association (NYHA) classes III and IV, dominant paced rhythm, and no left bundle branch block in the pre-pacing ...
van Gelder Berry M - - 2005
OBJECTIVES: We sought to investigate the effect of intrinsic conduction over the right bundle on the maximum rate of left ventricular pressure rise (LVdP/dt(max)) during left ventricular (LV) pacing compared to biventricular (BiV) pacing. BACKGROUND: Simultaneous BiV pacing and LV pacing both improve LV function in patients with heart failure ...
van Huysduynen Bart Hooft - - 2005
BACKGROUND: Proarrhythmic effects of cardiac resynchronization therapy (CRT) as a result of increased transmural dispersion of repolarization (TDR) induced by left ventricular (LV) epicardial pacing in a subset of vulnerable patients have been reported. The possibility of identifying these patients by ECG repolarization indices has been suggested. OBJECTIVES: The purpose ...
Di Pede Francesco - - 2005
INTRODUCTION: Spontaneous or pacing-induced interatrial conduction delay may affect the outcome of heart failure patients treated with cardiac resynchronization therapy (CRT). The objective of this study was to evaluate the impact of the atrial pacing site (right atrial appendage, RAA; and low interatrial septum, LIS) during biventricular (BV) pacing on ...
Pastore Carlos Alberto - - 2006
Body surface potential mapping assessed mean cardiac electrical activation times displayed by isochronal maps in the right ventricle (RV; right ventricle mean activation time [mRV]), anterior septal area (anterior septal area mean activation time [mAS]), and left ventricle (left ventricle mean activation time [mLV]) of 28 patients (mean, 61.07 years; ...
Petrac Dubravko - - 2005
AIM: To compare ventricular rate responsive (VVIR) pacing with dual chamber rate responsive (DDDR) pacing and antiarrhythmic drugs for the treatment of patients with persistent atrial fibrillation after atrioventricular node ablation. METHODS: One hundred two patients with persistent atrial fibrillation eligible for the atrioventricular node ablation were randomly assigned to ...
Lee Pi-Chang - - 2005
BACKGROUND: Atrioventricular nodal reentrant tachycardia (AVNRT) can be usually induced by atrial pacing or extrastimulation. However, it is less commonly induced only by ventricular pacing or extrastimulation. OBJECTIVE: The purpose of this retrospective study was to investigate the electrophysiologic characteristics in patients with slow-fast form AVNRT that could be induced ...
Peichl Petr - - 2005
BACKGROUND: Biventricular pacing (BiV) is employed as the current standard for cardiac resynchronisation therapy. Other pacing modalities have been proposed as alternatives; however, data on changes in electrical activation sequence caused by pacing from various sites are limited. AIM: To describe changes in activation patterns during different ventricular pacing modes ...
Gabor Sabine - - 2005
OBJECTIVE: Cardiac re-synchronization therapy for treatment of heart failure requires transvenous insertion of both a right ventricular and left ventricular pacing lead. Implantation of the latter by way of the coronary sinus often fails. Therefore, alternative techniques for insertion are required. We applied a simple video-assisted surgical technique (VATS) using ...
Doshi Rahul N - - 2005
BACKGROUND: Chronic right ventricular pacing has been reported to promote cardiac dyssynchrony. The PAVE trial prospectively compared chronic biventricular pacing to right ventricular pacing in patients undergoing ablation of the AV node for management of atrial fibrillation with rapid ventricular rates. METHODS AND RESULTS: One hundred and eighty-four patients requiring ...
Laske Timothy G - - 2005
BACKGROUND: Advances in endocardial device design have been limited by the inability to visualize the device-tissue interface. The purpose of this study was to assess the validity of an isolated heart approach, which allows direct ex vivo intracardiac visualization, as a research tool for studying endocardial pacing systems. METHOD OF ...
Wang Ruxing - - 2005
To observe blood B-type natriuretic peptide (BNP) level changes and the clinical implications in different periods and different cardiac pacing modes, the BNP levels of 105 patients with permanent cardiac pacing were assayed before pacemaker implantation and 1 day, 1 week, 1 month, 3 months, 6 months, and 9 months ...
Miyoshi Fumito - - 2005
BACKGROUND: The recent studies showed that right ventricular (RV) pacing was associated with worsening of heart failure. The aim of this study is to clarify the clinical significance of paced QRS duration during RV pacing to predict congestive heart failure (CHF) patients. METHODS AND RESULTS: This study enrolled in 92 ...
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