Active clinical trials for "Heart Block"

The purpose of this study is to determine the effectiveness of the Micra AV 2.0 device during exercise or elevated heart rates. Participation in research studies is voluntary. In this study, participants will already be planned to have a Micra AV 2.0 device implanted. Participants will then undergo treadmill exercise testing and wear a Holter monitor. For each participant, the tracking performance of the Micra AV 2.0 will be evaluated at rest and during exercise. Follow up visits will occur as part of standard of care and each participant will be enrolled in the study for up to 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%

The purpose of this registry is to evaluate the safety and effectiveness of LBBA pacing/sensing in patients already implanted with the Tendril STS 2088 lead.

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 purpose of the Micra Atrial TRacking Using A Ventricular AccELerometer 2 (MARVEL 2) study is to demonstrate safe and effective operation of the MARVEL 2 features for providing AV synchronous pacing in patients with normal sinus node function and AV block

The aim of this study is to compare the effectiveness of multiple modalities of cardiac resynchronisation therapy using high precision acute electrical and haemodynamic measurements.These modalities include biventricular pacing and conduction system pacing utilising His bundle and left bundle pacing. Conduction system pacing is a more physiological form of pacing. The study hypothesises that this will produce more effective cardiac resynchronisation.

Some newborns are born with congenital heart block (CHB), a condition occurring in babies with neonatal lupus. The first part of the study will test the effectiveness of fluorinated steroids, including dexamethasone, in improving the heart function and general health of newborns who have auto-antibody-associated CHB. The second part of this study will use ultrasound and heart monitoring to observe high-risk pregnant women and their fetuses during the third trimester of pregnancy.

The purpose of this study is to analyze the effect of left ventricular lead pacing location in the non-left bundle branch block (non-LBBB) heart failure patient population. The left ventricular lead pacing location will be guided by either the pacing site with the largest amount of dyssynchrony as measured by the LV electrical delay (QLV) or the physician's standard of care implant approach.

The study aims to use cardiac MRI scans and analysis techniques to evaluate differences in cardiac function after 12 months of pacing in patients with pacing leads placed in different positions within the right ventricle (apically or septally).