Clinical Research Directory

Efficacy and Safety of Catheter abLation in patiEnts With seVere mitrAl regurgiTation and pErsistent Atrial Fibrillation: a Randomized Controlled Trial

Atrial fibrillation (AF) leads to atrial functional mitral regurgitation (MR) through mechanisms including mitral annular dilatation, systolic leaflet motion distance alteration, and contractility decrease. Compared with primary MR, atrial functional MR due to AF and other diseases tends to have a worse prognosis, with a higher risk of death and heart failure hospitalization. MR and AF co-exist and exacerbate left atrial dysfunction, further causing worse cardiac dysfunction, valvular regurgitation, and aggravating prognosis. The best therapy for secondary MR is unclear because MR is only one component of the disease, and restoration of mitral valve competence is not curative. Catheter ablation improves symptoms and cardiac function in patients with AF, reduces risks of AF recurrence and hospitalization, as well as increases quality of life. For patients with AF combined with functional moderate-to-severe MR, previous observational studies have found that the severity of MR significantly reduced after taking catheter ablation to restore sinus rhythm. We hypothesized that catheter ablation would significantly improve the severity of MR in patients with severe atrial functional MR combined with persistent AF compared with drug therapy alone.

Catheter Ablation Plus LAAO Versus Anticoagulation in Frail Elderly Patients With Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia, significantly increasing the risk of stroke, heart failure, hospitalization and death in patients. Studies have shown that standardized anticoagulation can effectively reduce the risk of stroke by 64% and the risk of death by 26% in AF patients. Therefore, both European and American guidelines recommend standardized oral anticoagulation (OAC) as an important treatment strategy for stroke prevention in AF patients. However, the use of OAC may also increase the risk of bleeding in patients. Results from large AF anticoagulation randomized trials show that the annual risk of anticoagulation-related bleeding mortality is 2% to 3%. Therefore, according to the guidelines recommendations, assessing the bleeding risk is necessary in patients with anticoagulant indications. Percutaneous left atrial appendage occlusion (LAAO) is a device-based therapy that aims to prevent ischemic stroke in patients with AF. For patients with contraindications to long-term anticoagulation therapy, LAAO can be considered as an alternative strategy to oral anticoagulation (Class II B recommendation) to prevent ischemic stroke and thromboembolism. Multiple studies have shown that LAAO is non-inferior to warfarin and novel oral anticoagulants in stroke prevention for non-valvular AF patients. Age is not only a risk factor for stroke but also an important risk factor for bleeding. In the elderly population, especially those with frailty, the risk factors for both stroke and bleeding are often increased. Currently, there is insufficient evidence to support the use of OAC in frail elderly patients with relative anticoagulant contraindications. Therefore, elderly AF patients may be one of the potential beneficiary groups for LAAO. However, most previous clinical studies on LAAO were based on small sample sizes to analyze their safety and efficacy, and clinical data on the safety and efficacy of LAAO in this high-risk population of elderly AF patients are still limited. To address this, the study aims to conduct a multicenter randomized controlled trial to compare the efficacy and safety of catheter ablation combined with LAAO versus catheter ablation combined with OAC in elderly AF patients with high bleeding risk, filling the gap in this research area. To address these limitations, this multicenter randomized controlled trial is designed to evaluate the efficacy and safety of catheter ablation combined with LAAO versus catheter ablation combined with OAC in elderly AF patients at high risk for bleeding. The primary objective of the study is to compare the 12-month incidence and time-to-occurrence of the composite clinical endpoint. This endpoint includes stroke/TIA, systemic embolism, ISTH-defined major bleeding. By establishing these metrics within the first year, the study aims to fill the current void in clinical evidence and provide a standardized treatment strategy for high-risk elderly patients. In addition to the primary endpoints, the study will conduct a comprehensive long-term evaluation extending to 24 months post-procedure to assess the durability of both treatment strategies. Secondary objectives include the assessment of perioperative safety, specifically focusing on serious intraoperative complications and major adverse events occurring within the first seven days after the LAAO procedure. The trial will also measure long-term rhythm control by tracking the rate of freedom from AF recurrence at the one-year and two-year marks. Furthermore, the study seeks to verify the hypothesized superiority of the ablation-plus-LAAO strategy in reducing the specific burden of anticoagulation-related major bleeding and stroke. Beyond clinical safety and efficacy, the trial will analyze the practical aspects of the two interventions, including procedural success rates, operation duration, fluoroscopy time, and the total duration of hospitalization. A critical component of the research involves identifying specific risk factors associated with complications, with a specialized focus on how frailty scores influence procedural tolerance and long-term prognosis. The study will further explore how different types of AF respond to the LAAO strategy and assess the impact of each treatment on non-major bleeding events. Ultimately, the trial aims to determine which strategy offers a superior improvement in the overall quality of life for elderly patients, thereby optimizing future clinical guidelines.

Relaxin Therapy for Atrial Fibrillation

Atrial fibrillation (AF) is the most common heart rhythm disorder. The presence of AF increases the risk of death and is associated with a 5-6-fold increase in stroke incidence, due almost exclusively to thrombus formation in the heart. Current therapies for AF are limited. The evaluation of new, more effective treatments for preventing AF recurrence remains a critical unmet clinical need. AF is considered a progressive disease that increases in prevalence with age and can convert from "paroxysmal" to "persistent" to "permanent" AF in a single individual. This progression results, in part, from high oxidative stress and progressive adverse electrical changes in the heart. Compelling preclinical and clinical data indicate that Relaxin, a naturally occurring peptide hormone, may reverse the electrical remodeling. Thus, our overall objective is to investigate the effects of Relaxin in Veterans who have failed medical management for symptomatic AF and is referred to Cardiac Electrophysiology Laboratory for catheter ablation and pulmonary vein isolation. We will determine whether Relaxin therapy, in addition to the standard of care, counteracts the oxidative stress-related electrical derangement and reduces the post-ablation AF burden. A unique aspect of this proposal is that it is based in part on observations derived from the basic, translational and computational labs of the PI and co-investigators and from the observations by the PI while caring for patients with AF. As such, this proposal represents a true progression from the bench to the bedside. If successful, our findings may lead to the design of a new, more effective treatment for a major unmet public health problem in the United States as well as the world.

PROMBot-HSM-FA: Protocol for a Feasibility Study of a Chatbot Platform to Collect Patient-reported Outcomes After AF Ablation

The goal of this clinical trial is to learn if using a WhatsApp-based chatbot called PROMBot-FA can help people recover after atrial fibrillation ablation. The main questions it aims to answer are: * Is the chatbot easy and practical for people to use after their procedure? * Do people find the chatbot helpful for sharing their symptoms and health updates? Researchers will compare follow-up care supported by the chatbot to standard hospital follow-up visits. Participants will: * Be randomly assigned to either use the chatbot or receive usual follow-up care. * Report their symptoms, well-being, and any problems after ablation for 3 months. * Complete short questionnaires about their experience using the chatbot. This study will help researchers understand whether chatbot follow-up is feasible and acceptable for people after atrial fibrillation ablation and guide future larger studies.

Substrate Remodelling and Targeted Ablation in AF

Atrial fibrillation (AF) is the most common heart rhythm disorder, affecting millions worldwide and causing symptoms such as palpitations, fatigue and breathlessness. It also increases the risk of stroke and heart failure, so effective treatment is essential. A treatment for AF involves catheter ablation, a minimally invasive procedure where problematic areas of the heart are targeted using controlled energy. This is done by passing wires called catheters, through blood vessels at the top of the leg all the way to the heart. However, this isn't effective for everyone and approximately half of patients experience a return of AF despite treatment. In this researcher-led study at St Bartholomew's Hospital , the investigators will use a method called electroanatomical mapping to make a 3D picture of the left atrium, the heart's upper left chamber. To make this picture more detailed, information will be collected - such as how strong electrical signals are (voltage), how fast and in which direction they travel through the heart to describe abnormal areas and areas of scar within the heart. Information will also be gathered about the routes electricity takes and the nerve activity in the heart muscle. These detailed maps will help to understand why AF can continue indefinitely in some people, why ablation works for some people and not others, and improve how ablations are done to make them more effective. All participants will undergo catheter ablation with these mapping methods integrated into the procedure. If AF recurs, patients will be invited for a second ablation targeting specific abnormal areas depending on the amount of scar found. This will be standardised across patients. Patients will be followed for 12 months, with structured visits at 3, 6, 9 and 12 months and 48-hour ECG recorders at 6 and 12 months. By tracking how the heart's structure and electrical behaviour evolve, the aim is to to see if map-guided ablation reduces the need for further procedures, lowers healthcare costs and improves quality of life. Ultimately, this study will provide clear, reproducible insights into AF mechanisms and yield practical guidance so clinicians can predict who will benefit from standard ablation treatment and who may require extra, map-guided treatment.

Investigation of Cardioversion Versus Therapeutic Ablation for Persistent AF (ORBICA-AF)

The main aim of the research is to investigate whether patients undergoing pulmonary vein isolation with catheter ablation for persistent atrial fibrillation (AF) will have lower rates of AF recurrence than those treated by DC cardioversion without an ablation procedure.

Lattice-tip Versus Irrigated-tip Catheter for Linear Ablation of the Cavotricuspid Isthmus. A Multicenter, Randomized Study.

The LINEAR study is designed to compare the procedural efficacy, efficiency and safety of linear radiofrequency ablation of the cavotricuspid istmus using either a standar irrigated-tip ablation catheter or lattice-tip ablation catheter .The primary focus of the acute procedural data analysis will be: Procedural efficacy: This will be evaluated based on the rate of bidirectional CTI block persistence after 60 min waiting period documented by high resolution activation mapping. Furthermore, provocative test with intravenous adenosine infusion will be conducted to exclude dormant CTI conduction. Procedural efficiency: This will be evaluated based on the number of RF lesions delivered, time to achieve bidirectional CTI block, and fluoroscopy exposure time. Procedural safety: The incidence of procedural complications will be recorded.

Randomized Controlled Trial- Ablation Strategy for Paroxysmal Atrial Fibrillation - Trigger and Substrate Guided Wide Area Radiofrequency Ablation Compared to Pulsed Field Ablation Pulmonary Vein Isolation

Atrial Fibrillation (AF) is a heart rhythm disturbance that affects over a million people in North America. AF can cause strokes, heart failure, poor quality of life and may lead to premature death. Catheter ablation has been shown to be superior to medications for symptoms, prevention of stroke and heart failure. AF recurrence is a problem after catheter ablation. Our research has found that in most cases AF recurrence occurs because the catheter procedure was ineffective. The objective of our clinical trial is to find out if a new method of performing the catheter procedure will be more effective in preventing AF recurrence compared to the current standard of care ablation procedure. Subjects will be randomly allocated to undergo either the standard of care ablation, or the novel patient tailored ablation. The novel method aims to understand the unique factors responsible for AF in each individual and uses this information to perform a patient-tailored catheter ablation procedure. This is expected to improve the results of AF ablation. The effectiveness and safety of the ablation procedure will be specifically evaluated in women to understand the effect of sex on AF ablation.

Effects of Music During Atrial Fibrillation Ablation Under Conscious Sedation

I. Background Atrial fibrillation, a common type of arrhythmia, is often treated with radiofrequency catheter ablation, a minimally invasive procedure that helps restore a normal heart rhythm. While this surgery is typically performed under "light sedation" (where patients remain semi-awake) and allows for quick recovery, many patients still experience significant anxiety during the procedure due to pain, unfamiliar surroundings, or concerns about surgical risks. Research shows that anxiety not only makes people more sensitive to pain but can also trigger physical tension, irregular breathing, and even affect the precision of the surgeon's movements-potentially prolonging the procedure or increasing the risk of complications. Currently, hospitals primarily rely on sedatives and painkillers to ease patient discomfort. However, these medications may cause side effects like low blood pressure or slowed breathing, which can be particularly dangerous for older patients with heart conditions. As a safer alternative, non-drug approaches like music therapy are gaining attention. Studies suggest that listening to music can reduce anxiety and pain in other medical settings (such as during biopsies or pre-surgery preparation), likely because it helps the body relax, reduces stress hormones, or distracts the mind. Yet, there's limited evidence on whether music can provide similar benefits during atrial fibrillation catheter ablation, especially in helping patients maintain steady breathing. To address this gap, the present study aims to explore how music interventions affect anxiety, pain, and breathing stability in patients undergoing atrial fibrillation catheter ablation. Investigators hope this research will offer practical solutions to improve patient comfort, reduce reliance on medications, and enhance surgical safety, while also providing scientific support for expanding non-drug therapies in cardiac procedures. II. Study Purpose To evaluate whether music during atrial fibrillation catheter ablation helps reduce patients' anxiety and pain, stabilize breathing, and improve satisfaction for both patients and doctors while making the procedure more efficient. III. Study Design Prospective randomized controlled trial IV. Study Plan 1. Participants Inclusion Criteria: * First-time atrial fibrillation ablation patients (aged 18-80) following clinical guidelines. * Willing to participate and sign consent. Exclusion Criteria: * Mental health issues (e.g., anxiety requiring medication, sleep disorders). * Hearing loss, communication difficulties, or need for general anesthesia. * Prior heart surgeries or catheter ablation, complex heart anatomy, or recent pain/sedation medication use. Grouping: Patients split evenly into "music group" or "control group," based on atrial fibrillation type (persistent or paroxysmal). 2. Sample Size 60 patients/group (120 total) will be chosen. 3. Blinding * Patients and doctors know the group assignment (music or no music). * Researchers assessing pain/anxiety and statisticians are blinded. 4. Data Collected * Basic info (age, weight, education). * Health history (smoking, heart conditions, medications). * Atrial fibrillation details (type, duration). * Test results (e.g., heart size, kidney function). 5. Pain/Sedation Protocol * Light sedation with fentanyl (adjusted as needed). * Extra midazolam given if heart rhythm needs electric correction. 6. Ablation Procedure * For Paroxysmal atrial fibrillation: Isolate lung veins. * For Persistent atrial fibrillation: Extra ablation lines on heart walls. * Power and pressure settings vary by heart area to balance safety and effectiveness. 7. Music Intervention * Music Group: Patients pick preferred music (classical, pop, etc.) played at 50-60 dB during procedure. * Control Group:\*No music. 8. Outcomes Measured Main Outcomes: * Pain: Rated by patients post-surgery using a face-based scale. * Anxiety: Measured before and after surgery with a standard questionnaire. Secondary Outcomes: * Breathing Stability: Breathing rate, pauses, and patterns. * Procedure Efficiency: Surgery duration, X-ray time, success rate. * Complications: Bleeding, heart injury, stroke risk. * Drug Use: Amount of painkillers needed. * Satisfaction: Ratings from patients and doctors (1-5 scale). * Doctor Fatigue: Self-reported by surgeons.

Empiric Pulsed Field Pulmonary Vein Isolation During Atrial Tachycardia Ablation in Adults With Congenital Heart Disease

This is a prospective, single-arm intervention trial whereby we will test the safety and efficacy of performing pulmonary vein isolation (PVI) using pulsed field ablation (PFA) in adult patients with congenital heart disease (CHD) who are presenting for atrial tachycardia (AT) ablation.

Persistent Atrial Fibrillation Without the Evidence of Low-voltage Areas

An effective therapy of persistent atrial fibrillation beyond pulmonary vein isolation remains unsatisfactory. Targeting endocardial low-voltage areas represents an approach of substrate modification. This prospective, randomized study investigated the efficacy of ablation of low-voltage areas versus PVI and additional linear ablations in patients with persistent atrial fibrillation in terms of single-procedure arrhythmia-free outcome and safety.

Preventive Catheter Ablation for Ventricular arrhythmiaS in Patients With End-sTage Heart faiLure

CASTLE-VT is a randomized evaluation of prophylactic ablative treatment of arrhythmogenic ventricular scar in patients referred for HTx evaluation and diagnosed with ICM. Ablation will be performed with the use of a substrate-based approach in which the myocardial scar is mapped and ablated while the heart remains predominantly in sinus rhythm. The primary end point is the composite of all-cause mortality, worsening of HF requiring prioritized transplantation or LVAD implantation. The main secondary study end points are all-cause mortality, cardiovascular mortality, incidence of implantable cardioverter-defibrillator (ICD) therapy, hospitalizations, Quality of life, time to first ICD therapy, number of device-detected ventricular tachycardia/ventricular fibrillation episodes, LV function, and exercise tolerance. CASTLE-VT will randomize 160 patients with a follow up period of 2 years.

Cavo-Tricuspid Isthmus Block Durability After Pulsed Electric Field Ablation

This study seeks to assess the acute durability of the CTI block when PEF energy is used. Second goal is to establish the optimal waiting time for the conduction recovery after PEF CTI ablation and to assess the utility of routine adenosine testing for dormant conduction. Moreover, this study aims to investigate the differences in acute efficacy and adverse events (hemolysis, coronary vasospasm) between the two available configurations (basket or flower) of the pentaspline Farawave catheter (Farapulse-Boston Scientific Inc, USA).

Outcomes of PFA Vs. RFA for Patients with PSVT: a Retrospective and Propensity Score Matching Study

The goal of this retrospective study is to compare the long-term follow-up outcomes of pulses field ablation (PFA) Vs. radiofrequency ablation (RFA) for the patients with paroxysmal supraventricular tachycardia (PSVT). The main question to answer is: Does the PFA was more effecient and safer that RFA for treatment of PSVT during procedure and after 1-year follow-up? Researchers will compare the acute and long-term efficiency and safety between PFA and RFA. 1. Recieved PFA or RFA 1 year ago 2. Finish the visit to the clinic at 1, 3, 6, 12 months for examinations and blood testings 3. Patients recieved PFA and PFA under propensity matched comparison according to differen variety of PSVT

Zero Fluoroscopy Voltage Guided vs. Linear CTI Ablation

Catheter ablation of the cavo-tricuspid isthmus (CTI) is the curative first-line therapy for typical atrial flutter. Currently, two approaches are used in clinical practice. In contrast to the conventional linear ablation approach, the Maximum voltage-guided (MVG) strategy aims to limit ablation to high voltage areas (HVAs) representing the detectable correlate of relevant conducting bundles. Data from registries show that the MVG technique is sufficient to reach comparable clinical outcome with significantly shorter ablation duration when compared to the conventional linear strategy. Despite growing evidence, however, data from properly powered prospective randomized trials are lacking and the linear approach still remains standard. In addition, data on radiation exposure are controversial. As a substrate-based approach, the MVG strategy requires detailed mapping and signal analysis for identification of the individual architecture and exactly targeted energy application. However, the spatial mapping resolution of large tip catheters is limited. The use of the MicroFidelity catheter technology (IntellaMiFi) with high resolution mini-electrodes at the 8 mm catheter tip can be expected to further improve the feasibility of a voltage-guided approach. In addition, the MVG approach theoretically may encompass an increased risk for clinically inapparent reconduction. A prospective study with predefined invasive re-evaluation of persistent CTI block is needed to further evaluate this issue. Objective of this prospective randomized study is evaluate the performance of the micro-sensor technology for zero-fluoroscopy voltage-guided ablation of typical atrial flutter (AFL) compared with a population undergoing conventional linear ablation including a predefined invasive re-evaluation of persistent CTI block in addition to clinical follow-up. The study has been approved by the responsible ethics committee.

Hybrid Score to Predict OTVA-SOO in Patients with Wide Basal QRS

Outflow tract ventricular arrhythmia (OTVA) is the most common type of ventricular arrhythmia, and catheter ablation (CA) is the primary treatment option for patients experiencing symptoms. Accurately identifying the origin site of OTVA is essential for effective catheter ablation, minimizing procedural risks, and enhancing treatment success. However, most studies that developed algorithms or scoring systems for distinguishing OTVA origins excluded participants with structural heart disease and those with paced rhythms from their study groups. A recent prospective evaluation of a hybrid score (HS) that integrates both clinical and ECG data to predict OTVA-SOO, including patients with cardiac implantable electronic devices and those with structural heart disease in our study. The presented study aimed to assess the effectiveness of the previously described hybrid algorithm in predicting OTVA-SOO in a patient population characterized by a wide basal QRS due to intraventricular conduction defects or paced rhythms. The Hybrid Score The Hybrid Score (HS), involves a sum of points based on clinical and ECG characteristics. Points are assigned as follows: one point each for being over 50 years old, male, and having arterial hypertension. ECG-based points are allocated according to QRS transition: 3 points for a transition in V1, 2 points for V2, 1 point for V3 if the R-wave in V3 is greater than 1 mV; 1 point is subtracted if V3 has an R-wave less than 1 mV, and further deductions or additions apply for transitions up to V6. A score ≤ 1 suggests an RVOT origin, whereas ≥ 2 suggests an LVOT origin. ECGs were recorded with a standard configuration at a 25 mm/s sweep speed. Premature Ventricular Contraction (PVC) Ablation Activation mapping of spontaneous OTVAs was conducted. The procedure aimed to abolish spontaneous OTVAs, with the site of ablation marking the site of origin (SOO). Collected data * Patient Information and Consent (procedure must be done within 60 days of consent) * Demographics (age, gender, etc.) * Vital signs (length, weight, etc.) * Medical history, including cardiovascular risk factors, cardiomyopathy and drugs * ECG data * Echocardiographic data (left ventricular ejection fraction and left ventricular end-diastolic diameter) * Procedure data (number of radiofrequency applications, site of effective ablation, total radiofrequency time, total fluoro time, points mapping, procedure time) * Adverse Events

Role of Endomyocardial Biopsy and Aetiology-based Treatment in Patients With Inflammatory Heart Disease in Arrhythmic and Non-arrhythmic Clinical Presentations: an Integrated Approach for the Optimal Diagnostic and Therapeutic Management

Myocarditis is a complex inflammatory disease, usually occurring secondary to viral infections, autoimmune processes or toxic agents. Clinical presentations are multiple, including chest-pain, heart failure and a broad spectrum of arrhythmias. In turn, outcome is largely unpredictable, ranging from mild self-limiting disease, to chronic stage and progressive evolution towards dilated cardiomyopathy, to rapid adverse outcome in fulminant forms. Subsequently, myocarditis is often underdiagnosed and undertreated, and optimal diagnostic and therapeutic strategies are still to be defined. This study, both retrospective and prospective, originally single-center and subsequently upgraded to multicenter, aims at answering multiple questions about myocarditis, with special attention to its arrhythmic manifestations. 1. Optimal diagnostic workflow is still to be defined. In fact, although endomyocardial biopsy (EMB) is still the diagnostic gold standard, especially for aetiology identification, it is an invasive technique. Furthermore, it may lack sensitivity because of sampling errors. By converse, modern imaging techniques - cardiac magnetic resonance (CMR) in particular - have been proposed as alternative or complementary diagnostic tool in inflammatory heart disease. Other noninvasive diagnostic techniques, like delayed-enhanced CT (DECT) scan or position emission tomography (PET) scan, are under investigation. 2. Biomarkers to identify myocarditis aetiology, predisposition, prognosis and response to treatment are still to be defined. 3. Arrhythmic myocarditis is largely underdiagnosed and uninvestigated. Importantly, myocarditis presenting with arrhythmias requires specific diagnostic, prognostic and therapeutic considerations. At the group leader hospital, which is an international referral center for ventricular arrhythmias management and ablation, a relevant number of patients with unexplained arrhythmias had myocarditis as underlying aetiology. The experience of a dedicated third-level center is going to be shared with other centers, to considerably improve knowledge and management of arrhythmic myocarditis. 4. The role of CMR, as well as alternative noninvasive imaging techniques, in defining myocarditis healing is a relevant issue. In particular, optimal timing for follow-up diagnostic reassessment is still to be defined, in patients with myocarditis at different inflammatory stages, either with or without aetiology-dependent treatment. 5. Uniformly-designed studies are lacking, to compare myocarditis among different patient subgroups, differing by variables like: clinical presentations, myocarditis stage, associated cardiac or extra-cardiac diseases, aetiology-based treatment, associated arrhythmic manifestations, diagnostic workup, and devices or ablation treatment.

Role of Endomyocardial Biopsy and Aetiology-based Treatment in Pediatric Patients with Inflammatory Heart Disease in Arrhythmic and Non-arrhythmic Clinical Presentations: an Integrated Approach for the Optimal Diagnostic and Therapeutic Management (MYOPED)

Myocarditis is a complex inflammatory disease, usually occurring secondary to viral infections, autoimmune processes or toxic agents. Clinical presentations are multiple, including chest-pain, heart failure and a broad spectrum of arrhythmias. In turn, outcome is largely unpredictable, ranging from mild self-limiting disease, to chronic stage and progressive evolution towards dilated cardiomyopathy, to rapid adverse outcome in fulminant forms. Subsequently, myocarditis is often underdiagnosed and undertreated, and optimal diagnostic and therapeutic strategies are still to be defined. This study, both retrospective and prospective, originally single-center and subsequently upgraded to multicenter, aims at answering multiple questions about myocarditis, with special attention to its arrhythmic manifestations. Optimal diagnostic workflow is still to be defined. In fact, although endomyocardial biopsy (EMB) is still the diagnostic gold standard, especially for aetiology identification, it is an invasive technique. Furthermore, it may lack sensitivity because of sampling errors. By converse, modern imaging techniques - cardiac magnetic resonance (CMR) in particular - have been proposed as alternative or complementary diagnostic tool in inflammatory heart disease. Other noninvasive diagnostic techniques, like delayed-enhanced CT (DECT) scan or position emission tomography (PET) scan, are under investigation. Biomarkers to identify myocarditis aetiology, predisposition, prognosis and response to treatment are still to be defined. Arrhythmic myocarditis is largely underdiagnosed and uninvestigated. Importantly, myocarditis presenting with arrhythmias requires specific diagnostic, prognostic and therapeutic considerations. At the group leader hospital, which is an international referral center for ventricular arrhythmias management and ablation, a relevant number of patients with unexplained arrhythmias had myocarditis as underlying aetiology. The experience of a dedicated third-level center is going to be shared with other centers, to considerably improve knowledge and management of arrhythmic myocarditis. The role of CMR, as well as alternative noninvasive imaging techniques, in defining myocarditis healing is a relevant issue. In particular, optimal timing for follow-up diagnostic reassessment is still to be defined, in patients with myocarditis at different inflammatory stages, either with or without aetiology-dependent treatment. Uniformly-designed studies are lacking, to compare myocarditis among different patient subgroups, differing by variables like: clinical presentations, myocarditis stage, associated cardiac or extra-cardiac diseases, aetiology-based treatment, associated arrhythmic manifestations, diagnostic workup, and devices or ablation treatment.

Left Atrial Posterior Wall Additional Isolation for Persistent Atrial Fibrillation Trial

The purpose for this study is to determine whether left posterior wall isolation (PWI) in addition to pulmonary vein isolation (PVI) is effective as ablation strategy for persistent atrial fibrillation (AF).

AF Ablation With High Power Short Duration RF

This is a prospective, multi-center, research study designed to evaluate the safety and efficacy of pulmonary vein (PV) isolation with high power short duration radiofrequency energy in patients with paroxysmal/persistent atrial fibrillation (AF). Subjects with paroxysmal/persistent AF will undergo catheter ablation using commercially approved devices (mapping system and catheters). Patients will be followed up for 12 months to measure the recurrence of AF and its predictors. The primary endpoint will be to investigate the association between clinical and procedural characteristics and the efficacy and the safety of PVI performed with HPSD. At least 850 consecutive will be enrolled to have an adequate statistical power for the analysis of the primary endpoint. We assume that the freedom form AF recurrence at 12 months will be 80%. Expected R\^2 (Cox-Snell) 0.1. Candidate variables to be included in the model:10. Shrinkage level: 0.9. Based on these assumption the minimum number of patients is 850 with 170 events and EPP 17.

Effect of Dapagliflozin on the Recurrence of Atrial Tachyarrhythmia in Patients Undergoing Catheter Ablation of Atrial Fibrillation

The goal of this clinical trial is to test the effect of Dapagliflozin on the Recurrence of Atrial Tachyarrhythmia in Patients Undergoing Catheter Ablation of Atrial Fibrillation. The main questions it aims to answer are: • If Dapagliflozin will reduce the recurrence of all atrial tachyarrhythmias \[atrial fibrillation (AF), atrial flutter (AFL) and atrial tachycardia (AT)\] greater than 30 seconds during one-year follow-up after catheter ablation. Participants will receive Dapagliflozin (FORXIGA) 10 milligram (mg) once a day (QD) for 3 months after catheter ablation of atrial fibrillation. Researchers will compare patients who receive usual care to see if Dapagliflozin will reduce the recurrence of all atrial tachyarrhythmias (AF/AFL/AT) during one-year follow-up after catheter ablation.

Japanese Catheter Ablation Registry

Japanese Cather Ablation (J-AB) Registry is a voluntary nationwide registry, performed by Japanese Heart Rhythm Society, collaborated with the National Cerebral and Cardiovascular Center. The objectives of this registry are to observe and describe developments in the catheter ablation treatment of arrhythmia in Japan and to provide reliable information on the type of activity performed and the facilities available in Japanese arrhythmia units.