View clinical trials related to Atrial Remodeling.
Filter by:Heart failure with reduced left ventricular ejection fraction (HFrEF) is the most common form of chronic heart failure in subjects ≤ 75 years of age. Beta-blocker therapy greatly reduces mortality and improves ventricular function in HFrEF patients, but 30-40% of patients do not show improvement in ventricular function with beta blockade. An extensive gene signaling network downstream from the beta1-adrenergic receptor, the primary target of beta-blocker therapy is likely important for development and progression HFrEF. Pathologic changes in this gene signaling network are only reversed towards normal levels when ventricular function improves. One potential mechanism for failure to improve ventricular function in HFrEF patients unresponsive to beta blocker therapy is a lack of heart rate reduction. Ivabradine is an FDA-approved medication believed to have therapeutic benefit in HFrEF patients through reduction in heart rate independent of beta-blockade. Ivabradine has been shown to reduce the risk of hospitalization for worsening HF in patients with stable, symptomatic chronic heart failure with reduced EF (≤ 35%)in sinus rhythm with resting heart rate ≥ 70 bpm and who are on maximally tolerated doses of beta blockers or who have a contraindication to beta blockers. Given the high rate of mortality and hospitalization of HFrEF patients even with current therapies, there is a large unmet need for improving HFrEF therapy. The goals of this study are to test the hypothesis that heart rate reduction is an important antecedent for improvement in ventricular function, and to identify components of the beta1-adrenergic receptor gene signaling network responsible for improvement in ventricular function caused by heart rate reduction.
The purpose of this study is to study clinical factors and (blood) biomarkers related to progression of Atrial Fibrillation (AF) in patients diagnosed with self-terminating AF with special reference to hypercoagulability. All patients will be continuously monitored for their atrial rhythm to assess AF progression, either through an implantable loop recorder (Reveal LinQ) or via the atrial lead of a cardiac implantable electronic device (CIED), both in combination with the CareLink home monitoring system. Remote monitoring and interrogation will be installed and used on a daily basis.
The study is aimed at testing the hypothesis whether atrial fibrillary rate (AFR), as a measure of atrial electrical remodeling assessed from surface ECG, is predictive of sinus rhythm maintenance after electrical cardioversion. Earlier studies performed in a retrospective fashion suggested that high AFR exceeding 350-360 fibrillations per minute is an independent predictor of AF relapse after cardioversion, particularly in patients with duration of AF episode not exceeding 30 days, however this hypothesis has not been tested in a prospective study. CASAF is an observational study that will enroll patients with short duration (< 30 days) AF admitted for electrical cardioversion. Admission ECG will be extracted in a digital format and processed off-line for estimation of AFR. AF relapse will be assessed during 6-weeks long follow-up period during which ECG control will be scheduled at week 1 and 6.
Cardiac resynchronization therapy with pacemaker alone, or in combination with a cardioverter-defibrillator, prolongs life and decreases risk of heart failure exacerbation in patients with low ejection fraction and wide QRS. Some patients achieve decrease in QRS duration 6 months after cardiac resynchronization therapy. Such phenomenon is called reverse electrical remodeling of native conduction. Retrospective analysis showed that reverse electrical remodeling of the native conduction after at least 6 months of CRT is associated with decreased rate of ventricular arrhythmias and better survival. This study is designed to study reverse electrical remodeling prospectively.
Atrial fibrillation (AF) is the most common arrhythmia present in 1% of population under 60 years of age and reaching up to 15% at 80 years. AF is associated with reduced quality of life, increased morbidity, mortality and health economic costs. Presentation of AF differs substantially among patients ranging from self-limiting short episodes (paroxysmal AF), longstanding episodes (persistent AF) where direct current (DC) cardioversion is needed, to chronic atrial fibrillation. Treatment of AF is individually tailored in accordance to symptoms, type of AF and thromboembolic risk. The standard treatment of symptomatic persistent AF is DC-cardioversion preceded by anticoagulant treatment with Warfarin. According to guidelines DC-cardioversion can be performed when anticoagulation treatment has been in therapeutic range for at least 4 weeks. However introduction of Pradaxa (Dabigatran) has enabled an earlier DC cardioversion, reducing time to cardioversion to a 3 week period. During anticoagulation treatment persistence of AF contributes to left atrial remodeling and increases in inflammatory and neurohumoral biomarkers. The prolonged duration of AF and the remodeling of the left atrium increase the risk of AF recurrence after DC-cardioversion. Early cardioversion of patients with persistent AF is possible if preceded by transesophageal echocardiography (TEE). The TEE guided DC- cardioversion, as demonstrated in the ACUTE study, is a safe and efficient alternative to conventional treatment. This treatment regime is not routinely used in clinical practice. The aim of this study is to compare early DC-cardioversion (within 72 hours) to conventional treatment (Pradaxa prior to DC-cardioversion). 140 patients with persistent AF will be randomized to early cardioversion preceded by TEE in accordance with guidelines or conventional treatment with Pradaxa for 4 weeks prior to DC-cardioversion. The investigators will determine the outcome in the two groups regarding: - Left atrial function and size assessed by left atrial strain, left atrial ejection fraction and left atrial volume. - Inflammatory and neurohumoral biomarkers including ANP, BNP,IL6 and CRP. - Time to recurrence of AF (AF documented by ECG or Holter monitoring) Comprehensive transthoracic echocardiography, 12 lead ECG, biomarkers and Holter monitoring will be performed at the time of randomization, 4 weeks, 3 month and 6 month post DC-cardioversion. Furthermore all patients will be followed for symptomatic AF recurrence for a period of one year. AF recurrence will be documented by 12 lead ECG.
A consequence of chronic RV pacing is a process of electrical remodeling that alters myocardial repolarization to reflect the altered depolarization induced by the RV lead. When RV pacing is discontinued, the altered repolarization persists for several weeks. This phenomena is traditionally described as "T-wave memory" based upon the 12-lead ECG appearance of inverted T-Waves. The investigators are using the ECGI technique to produce three dimensional electroanatomical images of this phenomena in patients with dual chamber pacemakers. Echocardiography will also be used to image the mechanical effects of RV pacing and T-wave memory. The images will show the spatial distribution of altered repolarization and allow us to correlate any mechanical consequences of this phenomena that may exist.
Aim of the study is to compare in hypertensive patients the effect of one year therapy with ACE-inhibitor (RAMIPRIL) or angiotensin II receptor blocker (IRBESARTAN) on left atrial remodelling and diastolic function.
The purpose of this study is to determine whether irbesartan will reduce the rate of recurrent atrial high rate episodes and the development of clinical sustained atrial fibrillation in patients with hypertension and permanent pacemaker.