[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"health-study-detail:100659009":3},{"organization":4,"outcomesModule":7,"designInfo":19,"detailedDescription":26,"studyPopulation":18,"armGroups":27,"interventions":41,"overallOfficials":18,"centralContacts":18,"locations":18,"responsibleParty":56,"collaborators":18,"id":58,"slug":59,"hasResults":60,"nctId":61,"briefTitle":62,"officialTitle":63,"acronym":18,"eligibilityCriteria":64,"healthyVolunteers":60,"sex":65,"minAge":66,"maxAge":18,"enrollmentInfo":67,"targetDuration":18,"studyType":70,"phases":71,"briefSummary":73,"conditions":74,"keywords":18,"overallStatus":77,"whyStopped":18,"lastUpdateSubmitDate":78,"lastUpdatePostDateStruct":79,"startDateStruct":82,"completionDateStruct":84,"leadSponsor":86,"locationsCount":18},{"fullName":5,"class":6},"China National Center for Cardiovascular Diseases","OTHER_GOV",{"primaryOutcomes":8,"secondaryOutcomes":13,"otherOutcomes":18},[9],{"measure":10,"description":11,"timeFrame":12},"Successful implantation of the Micra leadless pacemaker","Defined as successful deployment of the Micra leadless pacemaker during the procedure with a pacing threshold \\\u003C 2.5 V @ 0.24 ms within 15 minutes before cutting the tether.","During Procedure",[14],{"measure":15,"description":16,"timeFrame":17},"The device-related serious adverse events occurring during the perioperative period","Defined as: death; prolongation of length of hospital stay by ≥48 hours; pacemaker malfunction (ventricular pacing threshold \\> 5 V\u002F0.24 ms or sensed R-wave amplitude \\\u003C 2 mV); pacemaker dislodgement; cardiac tamponade; rehospitalization for cardiac causes; vascular complication requiring surgical intervention; or system revision. A clinical events committee comprising independent physicians will review and adjudicate all system- and procedure-related events to determine their relatedness and whether any related event meets any criteria for a major complication. System revision includes any invasive modification of the device (e.g., replacement, repositioning, or removal) or programming of the device to an off state (OOO mode).","intraoperatively or before discharge",null,{"allocation":20,"interventionModel":21,"interventionModelDescription":22,"primaryPurpose":23,"observationalModel":18,"timePerspective":18,"maskingInfo":24},"RANDOMIZED","PARALLEL","The study will use a central randomization system to perform stratified block randomization, with study site as the stratification factor and a block size of 6. Patients who meet the eligibility criteria will be randomized 1:1 to the intervention group (leadless pacemaker implantation guided solely by transthoracic echocardiography) or the control group (leadless pacemaker implantation guided solely by fluoroscopy).","TREATMENT",{"masking":25,"maskingDescription":18,"whoMasked":18},"NONE","Currently, research on leadless pacemakers has primarily focused on device optimization and long-term postoperative follow-up assessment, whereas relatively few studies have investigated imaging innovations related to procedural techniques and methods. This study is designed to preliminarily explore the feasibility and safety of TTE-guided leadless pacemaker implantation and systematically evaluate the value of TTE in leadless pacemaker implantation, thereby providing a novel and effective procedural approach to leadless pacemaker implantation. This study may also facilitate the further development of leadless pacemaker implantation technology and provide patients with safer and more convenient treatment options\n\nThis study consists of two stages. Stage 1: to establish a standardized operating procedure for TTE-guided Micra leadless pacemaker implantation through combined echocardiographic and fluoroscopic guidance and mutual verification. Stage 2: to conduct a multicenter, prospective, randomized controlled study comparing the acute procedural success rate and complication rate between TTE-guided and conventional fluoroscopy-guided leadless pacemaker implantation to evaluate acute safety and effectiveness and provide high-quality evidence to support the subsequent clinical adoption of this technique.\n\nStage 1: Exploration of the Standard Operating Procedure Patients who meet the eligibility criteria will undergo the procedure according to the standard operating procedure under fluoroscopic guidance or using TTE guidance with fluoroscopic verification to explore the key techniques of TTE guidance, with intraoperative data collected.\n\nStage 2: Multicenter Randomized Controlled Study Phase On the basis of sufficient procedural experience accumulated and the establishment of a standard operating procedure during Stage 1, a multicenter, prospective, randomized controlled study will be conducted to compare TTE guidance with conventional fluoroscopic guidance for leadless pacemaker implantation in terms of procedural success rate, procedure duration, pacing parameters, and complication rate, and to evaluate differences in procedural success rate and complication rate between the two guidance methods. Operators participating in Stage 2 shall have experience with at least 5 cases of TTE-guided Micra leadless pacemaker implantation.",[28,35],{"label":29,"type":30,"description":31,"interventionNames":32},"Transthoracic echocardiography-guided group","EXPERIMENTAL","Use transthoracic echocardiography to guide the implantation of a leadless pacemaker",[33,34],"Procedure: Transthoracic echocardiography-guided","Device: Leadless pacemkaer",{"label":36,"type":37,"description":38,"interventionNames":39},"Conventional fluoroscopy-guided group","ACTIVE_COMPARATOR","Use conventional fluoroscopy to guide the implantation of leadless pacemaker",[40,34],"Procedure: Conventional fluoroscopy-guided",[42,47,51],{"type":43,"name":44,"description":45,"armGroupLabels":46,"otherNames":18},"PROCEDURE","Transthoracic echocardiography-guided","1. Preoperative Preparation:\n\n   Perform preoperative assessment using TTE to evaluate cardiac chamber anatomy and ultrasound image quality.\n\n   Individually adjust the ultrasound system settings according to patient characteristics and record key anatomical landmarks.\n2. Intraoperative Procedure:\n\nUse real-time TTE to guide the pacemaker delivery catheter through the right atrium to the right ventricle.\n\nObserve the catheter trajectory and identify the target region. After confirming electrode contact, complete pacemaker fixation and record the imaging findings in real time.",[29],{"type":43,"name":48,"description":49,"armGroupLabels":50,"otherNames":18},"Conventional fluoroscopy-guided","Leadless pacemaker implantation is performed under fluoroscopic guidance in accordance with current standard clinical practice.",[36],{"type":52,"name":53,"description":54,"armGroupLabels":55,"otherNames":18},"DEVICE","Leadless pacemkaer","Commercially available leadless pacemaker system implanted in all study participants.",[36,29],{"type":57,"investigatorFullName":18,"investigatorTitle":18,"investigatorAffiliation":18,"oldNameTitle":18,"oldOrganization":18},"SPONSOR","100659009","ultrasound-guided-leadless-pacemaker-implantation-100659009",false,"NCT07857330","Ultrasound Guided Leadless Pacemaker Implantation","A Study on the Feasibility of a Novel Guidance Method for Leadless Pacemaker Implantation","Inclusion Criteria:\n\n1. Age ≥ 18 years, regardless of sex;\n2. Patients with indications for permanent pacemaker implantation who are expected to have a low ventricular pacing burden, or patients who are expected to have a high ventricular pacing burden (≥40%) but have normal cardiac function, including complete or intermittent high-grade atrioventricular block, intermittent sinus arrest, and persistent sinus bradycardia (meeting the indications for implantation specified in the Chinese expert consensus on leadless pacemaker (2022)), particularly those with the following conditions: renal insufficiency, contraindications to X-ray radiation exposure, or potential adverse consequences from X-ray radiation exposure, as these patients are most likely to directly benefit from the ultrasound-guided procedure;\n3. Patients who have signed informed consent form.\n\nExclusion Criteria:\n\n1. Those with significant chest wall deformity (e.g., severe pectus carinatum or barrel chest) or severe obesity affecting transthoracic echocardiography image quality;\n2. Those with severe anatomical abnormalities of the right heart (e.g., an excessively small right ventricle, severe tricuspid regurgitation, Ebstein anomaly, or arrhythmogenic right ventricular cardiomyopathy);\n3. Those with presence of any lead from an existing pacemaker, implantable cardioverter-defibrillator (ICD), or cardiac resynchronization therapy (CRT) device;\n4. Those with presence of a mechanical tricuspid valve prosthesis, inferior vena cava filter, or left ventricular assist device (LVAD);\n5. Those with known intolerance to nickel-titanium alloy (nitinol);\n6. Those with concurrent active infection (e.g., bacteremia or infective endocarditis) or uncontrolled systemic infection;\n7. Those with life expectancy \\\u003C 1 year;\n8. Those who have recently undergone another interventional cardiac procedure that may interfere with the study results;\n9. Those who are unable to complete study follow-up, such as cognitive impairment or extremely poor adherence.","ALL","18 Years",{"count":68,"type":69},288,"ESTIMATED","INTERVENTIONAL",[72],"NA","The leadless pacemaker is a novel pacing technology that has emerged in recent years. Compared with conventional lead pacemakers, its design avoids many complications associated with leads and pacemaker pockets, including lead fracture, pocket infection, and venous access stenosis. Because of its small size and the absence of a pacemaker pocket or pacing lead, the leadless pacemaker is particularly suitable for patients with contraindications to conventional pacemaker implantation, including patients undergoing hemodialysis, patients with recurrent pocket infection, and patients without suitable vascular access.\n\nCurrently, leadless pacemaker implantation is performed primarily under fluoroscopic guidance. Fluoroscopy provides real-time intraoperative anatomical localization information but places high demands on the operator's technical skills and the precise intraoperative positioning of the pacemaker. However, procedures performed under fluoroscopic guidance require dedicated procedure rooms and radiation-generating equipment. Such large-scale equipment is expensive, and it requires special protective measures that make the surrounding walls, doors and windows meet the protection standards, so as not to cause harm to the surrounding environment and personnel. When procedures are performed under fluoroscopic guidance in dedicated catheterization laboratories, both operators and patients are exposed to potential health risks, and fluoroscopy-guided procedures are contraindicated in some pregnant women. In addition, X-ray imaging remains two-dimensional, and visualization may be inadequate in some patients because of individual anatomical variation, potentially increasing procedural difficulty. Therefore, exploring a radiation-free, real-time, and accurate guidance method has become a key approach to improving the success rate and safety of leadless pacemaker implantation.",[75,76],"Leadless Pacemaker","Transthoracic Echocardiography","NOT_YET_RECRUITING","2026-09-29",{"date":80,"type":81},"2026-10-05","ACTUAL",{"date":83,"type":69},"2026-10-20",{"date":85,"type":69},"2028-07-20",{"name":5,"class":6}]