Active clinical trials for "Atrioventricular Block"

The primary purpose of the study is to evaluate if patients with a standard indication for permanent ventricular pacing, left ventricular ejection fraction without limit, or any QRS duration will profit from the prevention of ventricular desynchronisation.

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

This study periodically assessed patients' cardiac function and prognosis by cardiac ultrasound, NYHA cardiac function class, 6-minute walk distance, quality of life score (QoL), and clinical events at follow-up, with the aim of assessing whether LBBP is no less effective than CRT in patients with left ventricular ejection fraction (LVEF) <50% and estimated percentage of ventricular pacing >40% of cardiac dysfunction.

Heart transplants save the lives of nearly 500 children in heart failure per year. Columbia is one of the largest pediatric heart transplant centers in the world, averaging 25 transplants per year, and providing ongoing care to nearly 250 children with transplanted hearts. After transplant, children are at increased risk to develop sudden onset of abnormally fast heart rates. This research project will study adenosine, a medication that is routinely used to slow fast heart rates in non-transplanted children (i.e. normal hearts), and its effects on the transplanted heart. Adenosine is often not used in patients with transplanted hearts because, based on prior limited research in adult patients, the standard adult dose may have a longer medication effect, producing a slower heart rate for an undesirable period of time. However, the current alternatives to adenosine treatment are either inappropriate for the pediatric age range, or have increased risk of unwanted side effects. This research project will answer two questions: is adenosine safe to give a child who has had a heart transplant, and will it be effective in treating the fast heart rate? All pediatric heart transplant patients undergo regular heart testing, known as a cardiac catheterization, one or more times per year. Three days before testing, participants will be asked to stop a regular medication, dipyridamole, because it slows the breakdown of adenosine in the body, and may increase its effects. (Of note, all patients that are on dipyridamole are also on aspirin, which gives a second line of heart protection, and will not be stopped.) After regular cardiac catheterization, all patients will already have intravenous (IV) access to give medication. Also, this setting allows the opportunity to have a back-up pacing catheter in the heart, ensuring that there will not be a longer than desired effect from the medication. Adenosine will be given per a low-dose protocol until either the medication effect is seen or the maximum dose is reached. There will be no difference in procedure recovery period time, and patients will resume regular home medications after finishing the test. As Columbia is one of largest pediatric heart transplant centers in the world, studying the effects of adenosine at low doses will benefit the investigators population greatly, either to find a new recommended medication dose, or to provide evidence that this medication is truly inadvisable for the investigators patients. The initial study was completed with all 80 patients enrolled and tested. Subsequent testing is now ongoing on patients in whom dipyridamole was stopped prior to their initial testing with a repeat study without discontinuing the dipyridamole. We anticipate re-testing about 30 of the 80 patients.

This is a randomized, prospective clinical trial to determine the effects of two different pacemaker atrioventricular delay (AV delay) settings on heart function in patients with dual chamber pacemakers implanted for symptomatic bradycardia with long PR intervals (delayed conduction between upper and lower chambers of the heart). The study will compare a long, fixed AV delay (standard) with an optimized AV delay for each individual using echocardiography (experimental).

The purpose of this study is to explore if there is a less harmful way to pace patients with first-degree AV-block to ensure that the negative effects inferred by the pacing do not outweigh the positive effects of AV-synchrony. The main hypothesis of the study is that His-bundle pacing will offer a more physiological mode of pacing in patients with first-degree AV-block than conventional pacing. Patients scheduled for catheter ablation of atrial fibrillation (AF) in sinus rhythm, with first degree AV-block, normal QRS duration less than 120 ms and normal left ventricular ejection fraction will be included. During the AF ablation three different pacing modes (atrial, AV-synchronous and His-bundle pacing) at two different rates (5 to10 bpm above the basal rate and at 100 bpm) will be performed and evaluated using echocardiography. After the completion of all six pacing protocols (i.e., three modes at two different rates) the experimental part of the procedure ends. The primary end-point will be echocardiographic evidence of dyssynchrony. Secondary end-points will include left ventricular ejection fraction, left ventricular volume, mitral regurgitation, septal to posterior wall motion delay and inter-ventricular wall motion delay. Since the research study is conducted in parallel with the standard catheter ablation, we do not anticipate any additional side effects as a result of the study.

The SEPTAL-PM study is aimed to compare the right ventricular apical and right ventricular septal position of the right ventricular lead in patients implanted with a pacemaker for conventional anti-bradycardia pacing indications requiring permanent right ventricular pacing ; the primary endpoint is the evolution of the left ventricular ejection fraction assessed by contrast echocardiography at 18-months follow-up.

Conventional right ventricular (RV) apical pacing may result in asynchronous ventricular contraction with delayed left ventricular activation, interventricular motion abnormalities, and worsening of left ventricular ejection fraction. His pacing is preserving a synchronous contraction and may prevent a decrease in left ventricular ejection fraction. Hypothesis: His-pacing preserves left ventricular function and is a feasable alternative compared to RV septal septal pacing in patients with AV-block.

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).

Heart failure is a progressive disease that decreases the pumping action of the heart. This may cause a backup of fluid in the heart and may result in heart beat changes. When there are changes in the heartbeat, sometimes a pacemaker is used to control the rate and rhythm of the heartbeat. In this trial, the researchers will test if pacing both the left and right lower half of the heart (ventricles) will: decrease the number of hospital and clinic visits due to heart failure symptoms extend life delay heart failure symptoms as compared to those who are paced in only one ventricle (the right ventricle)