Interview with Dr. Liu Changcheng of Anzhen Hospital: Efficacy of Bipolar Radiofrequency Ablation Guided by 3D Electroanatomical Mapping

A lifetime of health and happiness is the wish many ordinary people hold for their loved ones, but this aspiration is ultimately difficult to achieve, with cardiovascular disease posing a particularly troubling challenge. According to the Report on Cardiovascular Diseases in China 2018, there are approximately 290 million patients with cardiovascular diseases in China, making it the leading threat to public health.

Among these, coronary heart disease (CHD) is one of the most common and detrimental cardiovascular diseases, affecting 11 million patients. After a massive myocardial infarction in CHD patients, the infarcted area exhibits ventricular wall dilation and thinning, along with transmural myocardial necrosis. The necrotic myocardium is gradually replaced by fibrous scar tissue, causing the thinned ventricular wall in the affected region to bulge outward. This results in loss of contractility or paradoxical motion during cardiac systole, leading to the formation of a ventricular aneurysm. Experts note that over 90% of ventricular aneurysms are associated with coronary heart disease.

Left ventricular aneurysm is a common complication following severe acute transmural myocardial infarction, often leading to heart failure, malignant arrhythmias, ventricular septal perforation, and left ventricular mural thrombus formation. Dr. Liu Changcheng from Anzhen Hospital stated, “Ventricular tachycardia associated with ventricular aneurysms is the primary cause of sudden cardiac death in patients with this condition, accounting for 44% of all deaths.”

In addition, ventricular aneurysms can lead to other serious consequences. Experts have summarized three major hazards associated with ventricular aneurysms: First, ventricular function is impaired due to the paradoxical motion of the aneurysm. Second, mural thrombi tend to form within the aneurysm; if a thrombus dislodges, it can cause various symptoms of thromboembolism. Third, since a ventricular aneurysm consists of necrotic myocardium, it predisposes patients to various ventricular arrhythmias.

For the treatment of ventricular arrhythmias associated with ventricular aneurysms, surgical resection of the aneurysm is currently widely recognized. However, aneurysm surgery is technically challenging and carries high risks, with elevated rates of mortality and complications, demanding high levels of surgical expertise and postoperative management. Liu Changcheng stated, “Currently, monopolar radiofrequency ablation and cryoablation, commonly used in cardiac surgery, also have drawbacks. Monopolar radiofrequency ablation often results in incomplete lesion formation and a high recurrence rate, while cryoablation causes significant myocardial injury, increasing the risk of heart failure and even death during the perioperative period.”

“Catheter-based radiofrequency ablation in cardiology is now relatively prevalent, targeting scar-related ventricular arrhythmias after myocardial infarction. However, catheter radiofrequency ablation cannot guarantee transmural ablation, and the recurrence rate of ventricular tachycardia remains as high as 50%.”

Liu Changcheng remarked, “In light of this situation, we considered treating the patient with a method capable of achieving complete ablation. Evidence indicates that radiofrequency ablation is an effective approach for managing atrial arrhythmias. Specifically, bipolar radiofrequency ablation can deliver uniform linear lesions simultaneously on both the endocardial and epicardial surfaces, penetrating the myocardium to achieve transmural ablation, and has been widely adopted both domestically and internationally. Therefore, our team initiated research on the use of bipolar radiofrequency ablation under the guidance of the CARTO mapping system (a three-dimensional cardiac electrophysiological mapping system) for the treatment of ventricular aneurysm complicated by ventricular arrhythmias.”

“Through research, under the guidance of Professor Gu Chengxiong, our team invented full-thickness myocardial radiofrequency ablation without cardiopulmonary bypass. This innovative technique is guided by the CARTO 3D cardiac electrophysiological mapping system to precisely locate the reentrant circuits causing ventricular tachycardia. Using bipolar radiofrequency ablation forceps, continuous linear transmural ablation is performed radially from the center of the ventricular aneurysm to its edge, effectively interrupting multiple potential reentrant circuits and suppressing ventricular aneurysm-associated ventricular tachycardia,” said Liu Changcheng.

“This innovative technology integrates advanced diagnostic and therapeutic techniques from both interventional and surgical cardiology, utilizing the CARTO mapping system to guide full-thickness myocardial radiofrequency ablation, while”Combined Off-Pump Coronary Artery Bypass Grafting and Ventricular Aneurysm Repair: A Single-Stage Procedure for Dual Anatomical and Electrophysiological Treatment of Ventricular Aneurysm Complicated by Ventricular Arrhythmias, simplifying complexity is an effective surgical strategy for treating patients with ventricular arrhythmias associated with ventricular aneurysms.”

According to Liu Changcheng, Anzhen Hospital has treated a total of 43 patients to date, with a 100% procedural success rate. At the 4-year follow-up, the efficacy rate of full-thickness myocardial radiofrequency ablation was 86%. “These results indicate that bipolar radiofrequency ablation guided by CARTO mapping achieves favorable clinical outcomes in treating ventricular aneurysm complicated by ventricular arrhythmias. This method is safe, effective, and holds promise for future development; however, its long-term efficacy requires further follow-up observation.”

“The number of patients we treat is relatively small due to our strict inclusion criteria for treatment. We have established rigorous surgical indications, and patients must meet all of the following conditions to be eligible for surgery: First, the patient must have severe coronary artery disease. Second, the patient must have a history of acute myocardial infarction. Third, the patient must present with a ventricular aneurysm. Fourth, the patient must have newly onset ventricular arrhythmias. Only when all these criteria are simultaneously met will we proceed with the surgical intervention.”

Furthermore, there are specific criteria for radiofrequency ablation of ventricular arrhythmias associated with ventricular aneurysms. First, the patient has a history of resuscitation from sudden cardiac death, indicating that ventricular aneurysm-related ventricular arrhythmias pose a life-threatening risk. Second, the patient experiences frequent episodes of non-sustained ventricular tachycardia with pronounced subjective symptoms. Third, electrocardiographic monitoring reveals more than 10,000 premature ventricular contractions per 24 hours. Such patients are at high risk and face an imminent threat of sudden cardiac death, making them suitable candidates for bipolar radiofrequency ablation performed off-pump.

Bipolar Radiofrequency Ablation under CARTO Mapping: Also Known as Off-Pump Transmural Myocardial Radiofrequency AblationBipolar radiofrequency ablation under CARTO mapping is also referred to as off-pump transmural myocardial radiofrequency ablation because the procedure—comprising coronary artery bypass grafting (CABG), left ventricular aneurysmoplasty, and radiofrequency ablation—is performed on a beating heart. Performing CABG on a beating heart avoids the use of cardiopulmonary bypass (CPB) during surgery, thereby reducing the risk of CPB-related complications. Furthermore, operating on a beating heart allows for more precise determination of the extent and size of the ventricular aneurysm, enhancing the accuracy of both aneurysmoplasty and radiofrequency ablation.

“Currently, widespread adoption is limited by certain constraints. First, hospitals must be equipped with a three-dimensional electroanatomic mapping system. Second, physicians need to have experience in managing this condition,” said Liu Changcheng. At present, only some visiting physicians who have studied at Anzhen Hospital have acquired a certain level of proficiency in this technique.

“Another challenge in promoting this approach is that the condition is highly complex, cases are difficult to identify, and some patients suffer sudden cardiac death before receiving treatment. Due to limited experience or inadequate equipment, some hospitals are reluctant to assume the risks associated with such procedures and instead refer patients to more experienced centers like ours. Consequently, widespread adoption faces certain difficulties.”

Liu Changcheng stated, “Although there are certain challenges in current promotion, the technology has demonstrated favorable outcomes to date. Therefore, we aim to further expand the case series and continue follow-up to assess long-term efficacy, while gradually promoting this technology nationwide through physician training and technical support.”

CARTO Mapping System is a type of three-dimensional electroanatomic mapping system developed by the global healthcare giant Johnson & Johnson. It enables both endocardial and epicardial mapping, facilitating not only precise three-dimensional reconstruction of cardiac electroanatomy but also mapping of intracardiac electrical signal conduction, localization of reentrant circuits, and determination of the target area for ablation.

The CARTO mapping system reconstructs a three-dimensional anatomical map of the heart by continuously tracking the displacement of a magnetic catheter within the cardiac chambers, based on changes in its spatial position relative to a fixed magnetic field. By moving an electrode catheter point-by-point within or on the surface of the heart, the system detects changes in cardiac electrical potentials and overlays potential maps and activation sequence maps onto the anatomical model, thereby completing three-dimensional electroanatomic mapping.

Three-dimensional electroanatomic mapping systems offer strong intuitiveness by integrating intracardiac electrophysiological data with intracavitary spatial anatomy, enabling the identification of activation origins, conduction sequences, reentrant circuits, and scar tissue, thereby facilitating catheter ablation of arrhythmogenic foci.

Three-dimensional electroanatomic mapping systems can assist physicians in better managing arrhythmias such as atrial fibrillation, atrial tachycardia, atrial flutter, frequent premature ventricular contractions, and ventricular tachycardia. Conventional two-dimensional electroanatomic mapping systems struggle to precisely locate radiofrequency ablation targets, resulting in low surgical success rates or even failure, which severely impacts patients’ quality of life and survival. In contrast, three-dimensional electroanatomic mapping systems can construct a three-dimensional model of the heart, providing a stereoscopic and intuitive visualization of cardiac anatomy and enabling precise target localization, thereby significantly improving procedural success rates.

The CARTO mapping system was the first 3D cardiac electrophysiology system to enter the Chinese market, thereby capturing the majority of the market share. Other systems available in the Chinese market include Boston Scientific’s Rhythmia 3D cardiac electrophysiology mapping system, Shanghai MicroPort EP MedTech Co., Ltd.’s Columbus® 3D cardiac electrophysiology mapping system, and Sichuan Jinjiang Electronic Technology Co., Ltd.’s 3D cardiac mapping system. Liu Changcheng stated, “Domestically produced 3D electroanatomical mapping systems have made significant progress and can meet the clinical requirements for bipolar radiofrequency ablation technology.”