Impact of Liwen Procedure in Obstructive Hypertrophic Cardiomyopathy on Arrhythmias

Study Overview
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Brief Summary
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The goal of this observational study is to learn about the occurrence of various arrhythmias ( tachyarrhythmia and bradyarrhythmia ) during or after Percutaneous Intramyocardial Septal Radiofrequency Ablation. The main questions it aims to answer are: To investigate the occurrence of various arrhythmias ( tachyarrhythmia and bradyarrhythmia ) during procedure and its relationship with clinical characteristics and procedural parameters To analyze the changes of 12-lead electrocardiogram and 24-hour dynamic electrocardiogram before and after Percutaneous Intramyocardial Septal Radiofrequency Ablation and their relationships with clinical characteristics and procedural parameters

Official Title
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Impact of Percutaneous Intramyocardial Septal Radiofrequency Ablation in Obstructive Hypertrophic Cardiomyopathy on Arrhythmias

Conditions
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Hypertrophic Cardiomyopathy, Arrhythmia

Intervention / Treatment
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* Procedure: Percutaneous Intramyocardial Septal Radiofrequency Ablation for hypertrophic obstructive cardiomyopathy (Liwen Procedure)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subject with symptoms that limit daily activities (New York Heart Association functional class >II, exercise-induced syncope) despite adequate medical treatment or when medical treatment is not tolerated Subject with a peak LVOT gradient≥50 mm Hg Subject volunteers for the Liwen procedure and received the procedure at the Hypertrophic Cardiomyopathy Center of Xijing Hospital. Exclusion Criteria: Subject with a peak instantaneous Doppler LVOT gradient of <50 mm Hg Subject with an indication for septal reduction therapy and other lesions requiring surgical intervention (e.g., mitral valve repair/replacement and papillary muscle intervention) Subject has end-stage heart failure

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Hypertrophic Obstructive Cardiomyopathy Patients underwent Liwen Procedure<br> | Procedure: Percutaneous Intramyocardial Septal Radiofrequency Ablation for hypertrophic obstructive cardiomyopathy (Liwen Procedure)<br>* Under transthoracic echocardiography (TTE) guidance, the puncture site is positioned at the apex. A guiding line is applied along the septal long axis and the radiofrequency ablation electrode needle(17G, Cool-tip™ RF Ablation System and Switching Controller; Medtronic, Minneapolis, MN, USA) pierced towards the hypertrophic anterior interventricular septum (AIVS) 8-10 mm from the subaortic valve. Each ablation lasts up to 12 min, and the ablation power gradually increases from 30-40W. Then, the ablation needle is withdrawn 10 mm to prepare for the next application. Overall, 3-4 applications are performed in each patient. The ablation creates an area of thermal coagulative myocardial necrosis that appears as a hyperechogenic reflection detected by TTE. If deemed necessary, we repeat the procedure at the posterior interventricular septum (PIVS).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| All-cause and cardiovascular mortality | All-cause and cardiovascular mortality (defined as sudden cardiac death, Heart Failure-related death, and heart transplant) were the primary outcomes. | From date of procedure until the date of first occurrence of outcome, assessed up to 1 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ventricular tacharrhythmia composite outcome | Unexplained syncope, resuscitated cardiac arrests, or appropriate implantable cardioverter-defibrillator charge. | From date of procedure until the date of first occurrence of outcome, assessed up to 1 years | 
| Arrhythmia | Complete heart block, new permanent pacemaker implantation, non-sustained ventricular tachycardia, sustained ventricular tachycardia, left bundle branch block, right bundle branch block, premature ventricular contractions burden more than 10% monitored by Holter. | From date of procedure until the date of first occurrence of outcome, assessed up to 1 years |