The emphasis on fluoroscopy-free electrophysiology procedures has been growing in the United States. Many different operators are reporting their experience of performing complex procedures without the use of ionizing radiation. Multiple articles, including those in EP Lab Digest, have highlighted this approach.1-3 This interest in fluoroscopy-free procedures has also spread to the developing world. In this article, we describe the first fluoroless ablation that was performed in Vietnam.
EP Programs in Hanoi
Hanoi is the capital of Vietnam and has a population of approximately 8 million people. There are four active electrophysiology laboratories in the city. The first and busiest EP lab is located in Bach Mai Hospital. The EP program here was developed in the late 1990s by Dr. Pham Quoc Khanh and Dr. Tran Van Dong, with the assistance of Dr. Thomas Bump from Chicago. Bach Mai Hospital currently performs approximately 1500 ablations a year, including complex left atrial and ventricular ablations. The physicians at Bach Mai routinely perform 6-8 ablations daily. Dr. Phuong Dinh Phan is the current chief of electrophysiology at Bach Mai Hospital and the president of the Vietnamese Heart Rhythm Society. The hospital has one dedicated EP lab with an EnSite Precision cardiac mapping system (Abbott). Bach Mai also has a second lab that is used for device implantation.
The newest electrophysiology laboratory is located at the Hanoi University Medical School. Dr. Nguyen Lan Hieu is the Vice Director of Hanoi Medical University Hospital, and Dr. Nguyen Thang leads the electrophysiology department at the university. The first ablation ever performed at the university was in late January 2019 during our visit. The medical school does not currently have a three-dimensional mapping system, but does perform right atrial ablations.
Finally, there is an electrophysiology laboratory located at E Hospital, which is a large teaching hospital located in the northwestern part of Hanoi. There are approximately 1000 inpatient hospital beds and 2000 outpatient visits daily. Dr. Ba Vu Van is the Director of the Cardiac Electrophysiology Laboratory in the cardiovascular center at E Hospital. The lab performs approximately 400 ablations per year, including complex left atrial and ventricular cases.
First Fluoroless Case
During our visit, we were able to help Dr. Ba perform the first fluoroless ablation in Vietnam at E Hospital. The patient was a 40-year-old male with several months of progressive palpitations, shortness of breath, and recurrent pleural effusions, with an ejection fraction of 35% and left ventricular enlargement. An ECG showed a narrow complex tachycardia with a rate of 131 bpm (Figure 1). The diagnosis of non-ischemic tachycardia-induced cardiomyopathy was made based on the ECG, echo, and clinical history. The patient was initially treated with medical therapy, including beta blockers, ACE inhibitors, digoxin, aldosterone antagonists, and a direct oral anticoagulant for one month. A repeat echocardiogram showed that the LVEF had improved to 56%, but the heart rate was still elevated at 108 bpm. Based on the continued tachycardia and the desire to be off medications, the patient elected to undergo an ablation procedure. During the first procedure, mapping with the EnSite Velocity System (Abbott) showed a microreentrant tachycardia originating from the anterior right atrial free wall. However, before an ablation could be performed, the tachycardia spontaneously terminated and sinus rhythm resumed. The tachycardia could not be re-induced, so ablation was not performed. As the patient continued to have symptoms of palpitations and shortness of breath, he elected to have a second procedure, approximately one month after his first one. Given the patient’s young age and prior exposure to radiation, Dr. Ba and colleagues decided to employ the latest fluoroscopy-free techniques with the assistance of physicians from Resource Exchange International (REI).
The patient was brought into the electrophysiology laboratory in a fasting state, and received conscious sedation. The EnSite Velocity System was employed, and catheter manipulation was guided by the 3D mapping system without fluoroscopy. The coronary sinus catheter was placed from the left subclavian access location. The catheter was advanced into the coronary sinus using the 3D mapping system and the electrograms. The remainder of the catheters were introduced using femoral venous access and followed cranially to the heart using the 3D mapping system. Dr. Ba was able to manipulate the catheters into the correct locations using only the 3D EnSite map and intracardiac electrograms. Using a Reflexion spiral catheter (Abbott), a 3D anatomic shell of the right atrium was made. With dobutamine infusion, the patient developed sustained runs of atrial arrhythmias, which we were able to map. With the 3D map, manipulation of the catheters without the utilization of fluoroscopy was easily accomplished.
Local activation time (LAT) mapping was created while the patient was in the tachycardia. Using a color contour of 1, the interpretation of the map is limited to 8 colors. White is the earliest location that then spreads in the following color scheme order: White[Red[Orange[Yellow[Green[Light Blue[Dark Blue[Purple. The 3D map showed the atrial tachycardia to be located in the anterior and superior portion of the right atrium, near the junction of the superior vena cava (Figure 2). A non-irrigated tip 4 mm non-contact force sensing catheter was used to place lesions in this location, and led to termination of the rhythm after 10 radiofrequency lesions were delivered. Contact force catheters are not available in Vietnam. In order to ensure success in this location, additional lesions were placed (Figure 3). Afterwards, we induced a second tachycardia. This was also located in a similar location, but slightly inferior to the prior tachycardia. A similar LAT map was made to localize the location (Figure 4). A series of ablation lesions were delivered in this location as well, which led to termination of the rhythm. Following this, we could not induce any further tachycardias, and the case was terminated. The total case time was approximately 3 hours. The patient was monitored overnight in E Hospital, and discharged the next day. The patient has done well since the ablation procedure, and has remained in normal rhythm. In addition, the patient’s ejection fraction has improved back to normal range.
About Resource Exchange International
Resource Exchange International (www.resourceexchangeinternational.org) is a nonprofit organization based in Colorado Springs, Colorado, whose mission is to provide education and training to physicians in developing countries that want to improve their medical knowledge. Since Dr. Sundaram and Dr. Krishnan had previously been to other countries in southeast Asia for EP medical missions, they were approached by Vietnamese EPs to assist with complex ablations. Given the regulatory requirements of practicing medicine in Vietnam, working with a group such as REI, which already had infrastructure for medical missions in Vietnam, made the trip feasible. REI currently has a presence in Egypt, Indonesia, Laos, and Vietnam. REI has multiple specialty groups, such as Pulmonary/Critical Care and Gastroenterology, that serve in Vietnam. REI has been working to improve the health of Vietnamese patients for over 20 years. This was the first electrophysiology team to visit Hanoi with REI; the EP team on this trip consisted of 5 electrophysiologists and 2 allied health professionals. Our goal is to develop an ongoing relationship with the EP community in Vietnam so that new ideas and techniques can be shared.
In this article, we describe the first ablation in Vietnam without the use of fluoroscopy. The benefits of fluoroless ablation have been realized in the developing world, and are becoming increasingly employed. Experienced operators in these countries can be quick to adapt to the latest techniques. With equipment similar to what is present in most electrophysiology labs in the United States and Europe, short periods of mentorship can be beneficial for learning new techniques.
For more information, please visit www.resourceexchangeinternational.org
Disclosures: The authors have no conflicts of interest to report regarding the content herein.
- Percell RL. The SANS FLUORO approach to ablation. EP Lab Digest. 2019;19(3):33-35.
- Razminia M. Fluoroless catheter ablation: taking steps forward using the cryoballoon. EP Lab Digest. 2015;15(2):28-29.
- Dell’Orfano J. Unleaded ablations: Starting a zero-fluoro ablation program. EP Lab Digest. 2019;19(1):28-30.