Active clinical trials for "Bundle-Branch Block"

The electromechanical dyssynchrony induced by the presence of LBBB is in some patients, but not all, the cause of progressive left ventricular systolic dysfunction and heart failure. Aims To investigate the clinical, ECG, imaging-derived features in a large cohort of patients affected by LBBB on ECG. To identify predictors of LBBB-induced LV systolic dysfunction and predictors of outcome in this population. To derive data which may have an impact on therapeutic management.

CRT is delivered from two electrodes on opposite sides of the heart [right (RV) and left ventricle (LV)] delivering stimulation for more efficient heart beats. There is flexibility in the sequence and temporal staggering of the stimulation from these two electrodes with a different optimum for different patients. However, standard techniques to figure out the optimal stimulation strategy like standard 12-lead surface electrical recording (ECG) or routine ultrasound have failed. The investigators have developed ECG imaging (ECGI) with 250 electrode surface recording combined with CT scan to reconstruct high resolution 4-dimensional panoramic electrical maps of the heart. The study seeks to enroll 56 patients undergoing CRT in a clinical trail to evaluate short and long term impact of using ECGI for optimal programming of CRT.

The purpose of this trial or study is to determine if pacemaker therapy can be a beneficial alternative to conventional medical therapy in patients with a history of moderate heart failure. The investigators are looking to enroll approximately 180 people in this trial. Patients will be randomized in two groups. One group will be implanted with a pacemaker and will continue to receive conventional medical therapy as prescribed by their doctor. The second group will continue to receive conventional medical therapy as prescribed by their doctor and will not be implanted with a pacemaker. Clinical histories, physical exams, and external device testing will be collected both at the time of enrollment in the trial and during follow-up study visits. Patients who enter the study will be seen for study visits at 1 month, 3 and 6 months.

RATIONALE: Cardiac resynchronization therapy (CRT) is known to improve cardiac performance and to reduce morbidity and mortality in reduced-ejection fraction heart failure (HFrEF) despite optimal medical therapy (OMT). Several studies have shown that patients with with left bundle branch block (LBBB) respond favourably to CRT, whereas there is less certainty about non-LBBB morphology. Specifically, whether patients with right bundle branch block (RBBB) and HFrEF benefit from CRT is unclear. Some studies suggest lack of favourable outcomes. It follows from this that VVI implantable defibrillator are implanted in most RBBB patients.On the other hand right ventricular bifocal stimulation could be useful as an alternative approach in patient with RBBB. It consists of two endocardial leads implanted in right ventricle. The first lead is implanted in His bundle area, and the second lead is in the right ventricle apex. In this way bifocal pacing could decrease the inter- and intraventricular delays, thus improving left ventricular hemodynamics. However no specifically randomized studies are designed to date. PURPOSE: To demonstrate the superiority of right ventricular bifocal stimulation over placebo (VVI implantable defibrillator) in RBBB and HFrEF despite OMT. DESIGN Multicenter prospective randomized, double blind cross-over study. MASKING Investigator responsible for device programming is masked from having knowledge about clinical, functional, and echocardiographic data. On the other hand echocardiographist is masked from having knowledge about stimulation mode. Patients are masked from having knowledge about their clinical, functional, and device data. POPULATION At least fifty patients would be enrolled. The enrollment period should be one year. Study overall duration should be two years. ELIGIBILITY CRITERIA RBBB and HFrEF (left ventricular ejection fraction ≤35%) in sinus rhythm, in NYHA class II-III or ambulatory IV despite OMT. EXCLUSION CRITERIA -Refusal or withdrawal of informed consent.Renal failure (glomerular filtration rate ≤ 60 ml/min).Life expectancy < 12 months.Active neoplasm.Permanent atrial fibrillation.40 days following acute coronary syndrome.Atrio-ventricular block (from second degree AV block).Valvular heart disease with surgery indications. PROTOCOL Each patient undergoes baseline assessment. Pharmacological therapy, hospitalization,NYHA functional class, QRS complex informations, type of heart disease and comorbidities are collected. Quality of life (QOL) is defined by Minnesota Living with Heart Failure questionnaire. Functional capacity is assessed by 6MWT (optionally by cardiopulmonary exercise test). Trans-thoracic echocardiogram is performed, analyzing: left-ventricle diameters and volumes, left-ventricle ejection fraction (LVEF), left atrial diameter and area, TAPSE,valvulopathy,systolic pulmonary artery pressure. All patients undergo bifocal right ventricular resynchronization therapy: right atrial lead is implanted, whereas the first ventricular lead is placed in His bundle area, and the second ventricular lead in the right ventricle apex. Then the leads are connected to the respective channels of a CRT-D generator.After the implant, all devices are programmed in VVI mode. After the first 40±10 days (first f-up) patients are 1:1 randomized to VVI mode 40 beats/minute (placebo arm) or bifocal DDD-mode 60 beats/minute (with VV delay 0 msec and optimal AV delay). After six months (second f-up) a clinical and instrumental assessment equal to baseline is performed, as well as devices electrical parameters control. Then arms cross-over is performed (from VVI-mode to bifocal DDD-mode and vice versa). At 12 months (end of follow-up) an evaluation equal to that performed at 6 months is assessed. Echocardiographic data are unravelled to the investigator responsible for device programming. In this way the stimulation mode able to determine the best clinical improved (VVI or bifocal DDD mode) is programmed and the study closes. PRIMARY ENDPOINT The main assumption is that bifocal stimulation can increase of at least 20% the distance walked during 6MWT in respect of baseline and VVI-mode.The primary endpoint is the distance walked (expressed by meters) during 6MWT, as assessed at baseline, 6-months follow-up and 12 months follow up. Specifically changes in 6MWT observed during bifocal DDD-mode compared to baseline and to VVI mode would be significative if there is an increase of at least 20%. SECONDARY ENDPOINT Secondary endpoint is bifocal stimulation therapy response, defined by at least one of the following criteria, evaluated at baseline, 6-months follow-up and 12 months-follow-up in comparison to baseline and VVI mode: NYHA functional class improvement; changes in 6MWT, defined by an increase in distance walked major or equal to 30%; LVEF improvement major or equal to 25%;Left ventricular telesystolic volume reduction major or equal to 15%

Several attempts have been made to refine selection criteria for cardiac resynchronisation therapy (CRT) in heart failure patients with reduced ejection fraction (HFrEF). Previously proposed parameters probably do not sufficiently reflect the underlying mechanical dyssynchrony of the left ventricle (LV). Earlier work of our research group suggests that better candidate selection can rely on the direct observation or measurement of this LV mechanical dyssynchrony by means of non-invasive imaging. In this study apical rocking and other non-invasive measures of LV mechanical dyssynchrony will be applied to evaluate regional myocardial workload and metabolism, and determine their predictive value in CRT response.

This study is looking at whether the electrical treatment provided by a special type of pacemaker called a Cardiac Resynchronization Therapy (CRT) pacemaker may keep a patient's heart failure from getting worse. When the lower heart chambers (i.e. ventricles) are electrically paced to beat together by the CRT pacemaker, blood may be pumped to the body more efficiently. The CRT pacemaker being studied in this clinical trial is approved by the US Food and Drug Administration (FDA) for patients with moderate to severe heart failure, whose hearts pump blood inefficiently. In the MIRACLE EF study, patients who have heart failure with slightly less inefficient hearts will be observed to see if the electrical pacing treatment is better than not getting the treatment. This study is being conducted to support FDA approval of this type of pacemaker for people whose heart failure is less inefficient.

Heart failure (HF) affects 5 million Americans and is responsible for more health-care expenditure than any other medical diagnosis. Approximately half of all HF patients have electrocardiographic prolongation of the QRS interval and ventricular dyssynchrony, a perturbation of the normal pattern of ventricular contraction that reduces the efficiency of ventricular work. Ventricular dyssynchrony is directly responsible for worsening HF symptomatology in this subset of patients. Resynchronization of ventricular contraction is usually achieved through simultaneous pacing of the left and right ventricles using a biventricular (BiV) pacemaker or implantable cardioverter-defibrillator. Clinical trial evidence supporting the use of BiV pacing in patients with prolonged QRS duration was obtained almost exclusively in patients with a left bundle-branch block (LBBB) electrocardiographic pattern. Recent evidence suggests that resynchronization of ventricular contraction in patients with LBBB can be obtained by univentricular left ventricular pacing with equal or superior clinical benefits compared to BiV pacing. Animal studies suggest that ventricular resynchronization can be obtained in subjects with right bundle-branch block (RBBB) through univentricular right ventricular pacing. No clinical trial evidence exists to support the use of BiV pacing in patients with RBBB. Thousands of patients with symptomatic HF and RBBB currently have univentricular ICDs in place for the prevention of sudden cardiac death. Most of these devices are currently programmed to avoid RV pacing. We aim to determine if ventricular resynchronization delivered through univentricular RV pacing improves symptoms in patients with RBBB and moderate to severe HF who have previously undergone BiV ICD implantation for symptomatic heart failure. We further aim to determine if ventricular resynchronization improves myocardial performance and ventricular geometry as detected by echocardiographic measures and quality of life for patients with HF and RBBB. We hypothesize that RV univentricular pacing delivered with an atrio-ventricular interval that maximizes ventricular synchrony is equivalent to BiV pacing for improvement in cardiac performance, HF symptoms, and positive ventricular remodeling in patients with HF and RBBB.

This clinical study has been designed to test whether a new pacing therapy would lead to improvement in heart function, symptoms and quality of life in a specific group of heart failure patients. This group has a unique electrical conduction problem (Right Bundle Branch Block) that did not respond well to the current available pacing therapy.

The present study will randomize 50 symptomatic heart failure patients with severely reduced left ventricular ejection fraction (LVEF) and a true left bundle branch block to either direct HIS-pacing or biventricular pacing and follow them for at least six months. The outcome is how often it is possible to achieve HIS-pacing at implant and during follow-up and if HIS-pacing leads to differences in symptoms or measurable clinical parameters as compared to biventricular pacing.

In adults with chronic low back pain, the investigators will compare the effectiveness of the medial bundle branch block on three lumbar levels (L3-L4, L4-L5 and L5-S1) performed either by radiographic guidance or by ultrasound approach according to a transverse approach. The objective of this study will be to evaluate the benefit of these both procedures on pain, on the practice of daily activities and the incidence of adverse events in order to show whether the two modalities are equivalent.