Heart Block

Researchers are evaluating two different pacing methods for patients with slow heart rates in this multi-center trial. The study compares the standard right ventricular pacing with a newer physiological pacing approach, which includes His bundle pacing or left bundle pacing. This trial aims to better understand the effects of these pacing methods on heart function and patient outcomes over time, including a sub-study focused on heart muscle changes related to pacing. Participants will receive a pacemaker implanted at a participating center and be randomly assigned to either right ventricular pacing or physiological pacing. For physiological pacing, if His or left bundle pacing is not successful, biventricular pacing will be used instead. The trial includes an optional echocardiographic sub-study for some patients to assess heart changes over 24 months. Participants will be followed for up to 78 months, with assessments at baseline and every six months. Researchers will measure outcomes such as survival, heart failure events, quality of life questionnaires, symptoms, device-related safety events, and heart rhythm data collected from the pacemakers. The sub-study will use echocardiograms to evaluate changes in heart volume and pumping efficiency. This comprehensive follow-up aims to capture both clinical effects and mechanistic insights of the pacing methods.

Researchers are studying chronic heart failure patients who have a specific heart conduction problem called nonspecific intraventricular conduction delay (NICD). This randomized, controlled trial aims to compare the effects of a newer pacing method called left bundle branch area pacing combined with left ventricular pacing (LOT-CRT) against the traditional biventricular pacing (BiVP) method. The goal is to see which method better preserves heart function in patients with NICD over a follow-up period of at least six months. Participants will be randomly assigned to one of two groups. In the LOT-CRT group, patients receive a right atrial lead, an implantable cardioverter defibrillator lead, a left ventricular pacing lead, and a left bundle branch area pacing lead. The BiVP group receives the same leads except for the left bundle branch area pacing lead. The study will follow participants for a minimum of six months to compare the effects of these pacing methods on heart function and clinical outcomes. During the study, participants will undergo assessments including echocardiograms to measure left ventricular ejection fraction at baseline and six months. Other evaluations include paced QRS durations, heart function classifications, quality of life questionnaires, walking tests, blood tests for heart failure biomarkers, and monitoring of arrhythmias and hospitalizations. Researchers will also track the success rate of the left bundle branch area pacing implantation. Safety and clinical outcomes will be closely monitored throughout the study, which is expected to last over three years for recruitment and follow-up.

Researchers are evaluating the safety and effectiveness of the AVEIR VR LP and AVEIR AR LP leadless pacemaker systems in patients who need pacemakers in France. This national registry study, called "France LEADLESS," aims to confirm how these devices perform under normal conditions in patients needing VVI(R), AAI(R), or DDD(R) pacemakers, and to collect information about patient characteristics and device indications. The study is observational, retrospective and prospective, and non-randomized, following patients who have received these devices. Participants in this registry have been or will be implanted with the AVEIR VR LP or AVEIR AR LP devices, either individually or used together. The study monitors the devices over time, focusing on their safety and effectiveness up to 24 months after implantation. Secondary measures include tracking device stimulation thresholds, detection, atrioventricular synchronization, and remaining service life over 36 months. The study involves no experimental treatments but follows real-world use of these leadless pacemakers. During the study, patient data and device performance are collected and monitored regularly for up to three years after implantation. Researchers evaluate safety and effectiveness outcomes and gather detailed patient and device information. Participants are followed to confirm how well the devices work and to monitor any changes or issues over time. The total participation duration can extend to 36 months after device implantation, allowing long-term observation of device function and patient status.

Researchers are studying atrial tachycardia (AT) that occurs after ablation of atrial fibrillation (AF) or cardiac surgery. This condition is difficult to treat due to the complex nature of the heart tissue and the mechanisms causing AT. The study aims to compare two methods of catheter ablation for AT—standard versus minimalized approaches—to see which leads to better arrhythmia-free survival. The trial is prospective, randomized, and conducted at multiple centers to improve understanding using new ultra-high-density mapping techniques. Participants will receive catheter-based ablation using radiofrequency to treat their AT. They will be randomly assigned to either a standard ablation approach or a minimalized ablation approach targeting the clinical AT. The study will evaluate various procedural details such as procedure duration, fluoroscopy time, radiofrequency application time, ablated heart area, and the number of blocked lines. Both groups will be monitored during the procedure with advanced mapping techniques to assess the underlying heart substrate and AT mechanisms. During the study, participants will undergo assessments including ECG documentation of AT, intraprocedural mapping, and evaluations of arrhythmia recurrence over one year. Researchers will measure the recurrence of sustained arrhythmia lasting more than 30 seconds as the primary outcome after one year. Other measures include inducibility of AT after ablation, predictability of secondary AT from mapping, and procedure-related parameters. Participants will be followed for safety and treatment effectiveness throughout the study period, which started in December 2020 and is expected to continue until June 2027.

Researchers are investigating the role of focal electrical activations in maintaining persistent atrial fibrillation (AF). The study evaluates a new mapping technique called RETRO-Mapping, designed to detect these focal activations during AF. This approach aims to better understand the mechanisms behind persistent AF and whether targeting these focal drivers can improve treatment outcomes compared to standard care. All participants will undergo a standard pulmonary vein isolation (PVI) procedure using advanced 3D electroanatomic mapping systems. After PVI, patients are randomly assigned to either a control group, which receives RETRO-Mapping without additional ablation, or an intervention group, where RETRO-Mapping is used to identify and ablate focal activation sites. The intervention includes mapping 30-second segments of the atria, ablating identified focal activations, and assessing changes in AF cycle length to evaluate treatment effects. Participants will be monitored through detailed intra-procedural measurements, including AF cycle length in the coronary sinus and left atrial appendage. The main outcome is the change in AF cycle length during the procedure, and a secondary outcome is freedom from AF one year after treatment. The study involves follow-up assessments and safety monitoring, with a total participation duration extending to at least one year to track long-term effects and recurrence.

Researchers are investigating the effects of cardiac resynchronization therapy (CRT) in patients with symptomatic heart failure who have a low left ventricular ejection fraction (LVEF of 35% or less) and left bundle branch block (LBBB). About one-third of patients receiving CRT do not show improvement, and this study aims to understand how CRT affects coronary blood flow in the left anterior descending artery (LAD) in patients with non-ischemic dilated cardiomyopathy and LBBB. The study hypothesizes that CRT improves heart function not only by resynchronizing the heart's contractions but also by enhancing blood flow in coronary arteries. The study will enroll 60 patients with heart failure caused by non-ischemic dilated cardiomyopathy and LBBB, some with CRT devices and some without. Researchers will measure absolute coronary flow and resistance in the LAD using invasive procedures, including fractional flow reserve (FFR), with CRT devices turned on and off to compare effects. These measurements will help evaluate how CRT influences blood flow and heart muscle work. Participants will undergo invasive flow measurements during the study procedure to assess coronary blood flow and heart function. Researchers will closely monitor absolute coronary flow during the procedure to understand the impact of CRT. The study is conducted at an outpatient cardiology clinic and involves assessing heart rhythm, medical therapy stability, and other heart health factors. The total duration and follow-up details are not specified, but the focus is on real-time measurements during the procedure.

Researchers are investigating how accurately a smartwatch can detect heart rhythm and conduction problems in patients with cardiovascular diseases. This observational study compares the heart readings from a smartwatch to those from a traditional 12-lead electrocardiogram (ECG) to see how similar the results are and how well the smartwatch's automatic diagnosis matches expert assessments. The study aims to improve early detection and monitoring of heart conditions to prevent serious health issues. Participants will have their heart activity recorded using an Apple Watch Series 4 and a conventional ECG device. The smartwatch will record two 30-second ECG tracings while the patient is at rest, attached to the left wrist with the right hand touching the sensor to complete the measurement. The conventional ECG will capture 12 leads including a 30-second rhythm trace. The smartwatch's automatic diagnoses will be compared with the conventional ECG results and interpreted by two independent cardiologists. During the study, participants provide clinical and demographic information and undergo both smartwatch and conventional ECG recordings. The researchers will analyze the similarity of heart rate, waveforms, and intervals between methods, along with the diagnostic accuracy of atrial fibrillation and other heart rhythm disorders. The main outcome is the agreement between the smartwatch and conventional ECG diagnoses. Safety and data quality will be monitored, and participants may withdraw at any time without affecting their medical care. The total study duration is around 30 days for outcome assessment.

Researchers are studying patients with non-valvular atrial fibrillation who are scheduled to have a combined procedure involving atrial fibrillation ablation and left atrial appendage (LAA) occlusion. This prospective, multi-center, randomized controlled trial aims to compare two methods for selecting the size of the LAA occluder device during the procedure. The study is sponsored by the First Affiliated Hospital of Shantou University Medical College and seeks to evaluate the accuracy of size selection using two imaging approaches. Participants are randomly assigned to one of two groups: the CT group, where the LAA occluder size is chosen based on preoperative cardiac CT measurements, and the DSA group, where size selection is guided by intraoperative digital subtraction angiography (DSA) measurements. Both methods are used after completing the atrial fibrillation ablation. The trial measures various outcomes including the accuracy of occluder size selection during the procedure, procedural success, procedure-related times, and incidence of major adverse events within three months after the procedure. Participants will have clinical follow-ups before hospital discharge and at three months after surgery, with telephone follow-ups conducted annually for up to five years. The study monitors procedure success, device-related leaks at three months, and any major adverse events related to the device or procedure. The total participation duration can extend up to five years, allowing careful assessment of both immediate and longer-term outcomes.

Atrial fibrillation (AF) is the most common heart rhythm disorder worldwide, affecting about 3% of adults and expected to increase due to longer lifespans and more diagnoses. This study aims to prospectively evaluate a large group of patients undergoing AF ablation to identify clinical and procedural factors that predict success in preventing arrhythmia recurrence over the medium to long term. The main goal is to determine which parameters best predict freedom from clinical atrial arrhythmias 12 months after the procedure. Patients with indications for AF ablation will receive treatment following standard care at participating centers. The study collects data on procedural success immediately after ablation and tracks patients for 12 months to monitor for arrhythmia recurrence, other atrial arrhythmias, and any adverse events. The study will also assess patient-reported outcomes, ECG changes before and after ablation, and healthcare resource use. This observational study enrolls consecutive patients meeting eligibility criteria without altering their treatment plan. Participants will be followed for 12 months after their ablation procedure, with data collected on clinical history, drug therapy, arrhythmia recurrences, adverse events, and patient symptoms. Evaluations include acute procedural success, ECG monitoring, and questionnaires on quality of life and symptom severity. Researchers will analyze these data to identify factors associated with long-term success and safety of AF ablation. This study provides real-world insights into the management and outcomes of patients undergoing AF ablation over time.

Researchers are evaluating the Agilis Radiofrequency (RF) Transseptal System to study its initial safety and performance in crossing the atrial septum for accessing the left atrium and left ventricle during cardiac electrophysiology and interventional cardiology procedures. This early feasibility study involves a first-in-human, acute setting without long-term follow-up visits. The research aims to assess both safety and procedure success during hospital stay. Participants will undergo a transseptal procedure using the Agilis RF TSP System, which employs a radiofrequency wire to cross the atrial septum. The study focuses on an acute procedure setting with monitoring through hospital discharge, with no additional follow-up visits required. The procedure intends to facilitate access for left atrial and left ventricular interventions. During the study, participants will be observed from the time of device insertion through discharge from the hospital. Researchers will measure the rate of serious adverse events related to the device or procedure and the success rate of transseptal access as determined by the physician. The total participation time covers the procedure and hospital stay, with safety monitored periprocedurally.