Spotlight Interview

Spotlight Interview: Ablation in Paradise: The Queen’s Medical Center

David Singh, MD
Electrophysiologist, The Queens Medical Center
Associate Professor of Medicine, John A. Burns School of Medicine
Honolulu, Hawaii

David Singh, MD
Electrophysiologist, The Queens Medical Center
Associate Professor of Medicine, John A. Burns School of Medicine
Honolulu, Hawaii

The Queen’s Medical Center (QMC), located in downtown Honolulu, Hawai‘i, is a private, non-profit, acute medical care facility. It was established in 1859 by Queen Emma and King Kamehameha IV to “provide in perpetuity quality health care services to improve the well-being of Native Hawaiians and all of the people of Hawai‘i.” Today, the Queen’s Medical Center is the largest private hospital in Hawai‘i, licensed to operate with 505 acute care beds and 28 sub-acute beds. The medical center has more than 3,000 employees and over 1,200 physicians on staff. As the leading medical referral center in the Pacific Basin, Queen’s offers a comprehensive range of primary and specialized care services.

What is the size of your EP lab facility? When was the EP program started at your institution?  

The Queen’s Medical Center currently operates 1 dedicated EP lab. Although catheter ablation has been performed here for many years, a formal complex ablation program was not established until 2011. Prior to this, patients often had to travel to the mainland for complex ablation procedures. 

What is the number of staff members? What is the mix of credentials at your lab? 

We currently have 5 dedicated staff members who work in the EP lab. Establishing an EP “team” has been a key element in our lab’s success. 

What types of procedures are performed at your facility? Approximately how many catheter ablations (for all arrhythmias), ICD implants, and pacemaker implants are performed each week? 

The QMC EP lab currently offers a full range of invasive EP services, including the implantation of pacemakers, defibrillators, and biventricular pacemakers/ICDs. Approximately 500 device procedures are performed each year. We have the largest atrial fibrillation (AF) ablation program in the state, performing approximately 100 AF ablations a year. In addition, we perform ablations for ventricular tachycardia (including epicardial) as well as for supraventricular tachycardia. We have been performing left atrial appendage occlusion (LAAO) procedures since 2014. Both our AF ablation and LAAO programs are part of a larger comprehensive AF management infrastructure that focuses on disease management.

Who manages your EP lab? 

Alice Gill Murray, RN is our current EP lab manager.

How long has the EP lab been separate from the cath lab?

Prior to 2011, our EP lab was not separate from the cath lab. As the case volume and complexity have increased dramatically over the years, there was widespread recognition that a separate lab with specialized staff was necessary to deliver state-of-the-art EP care. 

Do you have cross training inside the EP lab? 

We try to keep this to a minimum.

What type of hospital is your EP program a part of?

The QMC is a private hospital that serves as one of the primary training facilities for the John A. Burns School of Medicine training programs. Medical students, residents, and fellows are actively involved in patient care. We are also the training site for the only cardiovascular disease training program in the state. The electrophysiology division at the QMC plays a key role in training of cardiology fellows, and ensures that they develop the competencies required for the management of heart rhythm disorders. 

What types of EP equipment are most commonly used in the lab? 

For 3D mapping, we use CARTO (Biosense Webster, Inc., a Johnson & Johnson company). Our EP recording system and fluoroscopy equipment are from GE Healthcare. We use implantable devices from all vendors.

How is shift coverage managed? 

Typical hours are from 7-7 each day.

Tell us what a typical day might be like in your EP lab.

EP cases are performed 5 days a week from 7:30 am to 6:00 pm, depending on the case volume. Tuesday, Wednesday, and Thursday tend to be our heavier days with respect to ablation cases. We will often perform 2 AF cases during the day, or an AF with 1-2 other ablation procedures as well as devices. Whenever possible, devices are implanted in the EP lab. 

What new technology has been recently added to the EP lab? How have these technologies changed the way you perform procedures?

We believe that our EP lab is a laboratory in the traditional sense of the word — that is, it functions not only as a location where procedures take place, but serves as a platform for innovation and change. Few fields in modern medicine are changing as fast as modern EP. Much of this change is driven by technological advances that make procedures safer and more effective. We are constantly striving to use emerging technologies to enhance the therapies that we provide. Some examples include:
  • Radiation reduction. Three years ago, we started a radiation reduction initiative in our EP lab. We recognized that radiation exposure to patients, operators, and staff should be minimized or eliminated whenever possible. We also recognized that the physical demand of wearing lead on a daily basis can have a sizable impact on the longevity of an EP career. Along with other pioneers around the country, we developed protocols to minimize radiation exposure. Our protocols rely primarily on 3D mapping systems and intracardiac echo (ICE). These protocols have evolved considerably over the last several years. For over a year now, we have utilized a zero-fluoroscopy workflow for our ablations. We have gained national and international recognition for these efforts, and are working to share our practices with the larger EP community through proctoring and publication of our experience. We are also currently working on developing low fluoro workflows for device implantation. 
  • Lesion assessment. One of the most challenging elements of cardiac ablation is determining adequate lesion assessment. Irrigated ablation catheters (SF), contact force (ST SF), and lesion assessment via modules like VISITAGE (CARTO, Biosense Webster, Inc., a Johnson & Johnson company) have enhanced our ability to deliver more predictable results. This is particularly important in AF ablation, where the delivery of contiguous transmural lesions is paramount. Over the years, we have analyzed data from our AF ablation cases to develop a workflow that is safe, efficient, and effective. With our current ablation parameters, we are able to achieve wide area antral isolation with a singular pass of the ablation catheter approximately 75% of the time (i.e., once we have encircled the veins, they are isolated and do not require additional lesions). This in turn has led to simplified workflows and shorter procedure times. Because we routinely isolate our veins on the first pass, we have found that a single transseptal puncture is usually adequate and requires minimal catheter exchanges. This is one of many examples that highlights how technology has allowed our procedures to become safer and more efficient without sacrificing quality.
  • The law of parsimony. We believe that despite the myriad of technologies available for catheter ablation, simple and reproducible protocols are the most desirable. Fortunately, modern mapping systems are highly sophisticated and little else is required to perform ablations. Rather than trying to master multiple technologies, we have focused on harnessing the power of just a few. The results have been extremely rewarding. We have found that an in-depth understanding of a technology platform is the cornerstone of innovation. As a result of this philosophy, we have been able to utilize our technology in creative manners, particularly when it comes to challenging cases. 
  • We practice AF disease management, not pulmonary vein isolation in isolation. Nowhere is the concept of disease management more important than in atrial fibrillation. Because AF ablation is an imperfect procedure even in the best of hands, we strongly believe that a multidisciplinary, patient-centered approach is essential for optimal AF management. Not everyone who is referred to our center for AF ablation undergoes the procedure. For some patients, weight loss or management of sleep apnea is the best treatment strategy. Even if ablation is warranted, we will routinely screen for sleep apnea and work closely with our weight management colleagues to maximize the likelihood of successful ablation. We also encourage practices such as yoga and meditation, which we believe may be useful in the management of this disease.  

What type of quality control and assurance measures are practiced in your EP lab?

Although it may not have the allure of emerging technologies, we have focused a great deal on quality in our EP lab. Our goal is to standardize practices that are evidence based, and create a culture of safety to ensure minimum harm to patients. Approximately one year ago, we implemented a mandatory reporting system for all complications that occur in the EP lab. Cath lab staff and the primary operator are expected to report any complication that occurs. These complications are logged into a database that is managed by our cath lab director. An EP quality committee was established consisting of operators and administrators to identify complication patterns and to devise solutions to address them. Although the primary goal of this initiative is to increase safety, the cultural shift is also important. Both operators and staff feel comfortable reporting complications, as they have come to recognize the importance of working together to promote safe practices. 

Are there plans for your EP lab to expand? 

Yes, we have quickly outgrown the capacity of our one EP lab, and have plans to expand to two labs in the near future. 

How do you ensure timely case starts and patient turnover?

Over the last year, we have focused on improving first case start times as well as turnover times in the EP lab. We are currently in the process of implementing a set of regulations that will help to ensure that the first case starts on time. For example, if the operator is going to be delayed by more than 45 minutes, other cases may be started in the interim. We have also recognized the value of data with respect to any quality improvement project. Turnover time is affected by a number of variables, including anesthesia, groin holding, patient characteristics, staffing, and many others. For the last six months, we have been gathering data regarding turnover times to better understand where there might be opportunities for improvement.  

What types of continuing education opportunities are provided to staff members?

We believe that it is essential for the EP lab staff to participate in educational programs to deepen their engagement and understanding of electrophysiology. Modern EP cannot be performed by a singular operator — it requires a coordinated team consisting of individuals with specific roles and responsibilities. An educated team is required to practice safe and effective ablation. We provide periodic educational sessions for our staff to ensure that they continue to learn and remain up to speed with evolving practice.

Describe a particularly memorable case from your EP lab and how it was addressed.

We recently had a remarkable case that hit very close to home when our director of cardiac services experienced sudden cardiac arrest while sleeping. His wife quickly initiated CPR and he was brought to our hospital, where he made a complete neurological recovery. An ICD was implanted, and he was discharged a few days later. Several days after discharge, we received a red alert via remote monitoring, indicating that he had had another episode of ventricular fibrillation while he slept. Fortunately, the event self-terminated while the device was charging, and the shock was aborted. It appeared that his event was triggered by a specific PVC. A few days later, he was brought to the EP lab. The findings were fascinating — a PVC arising from the junction of the moderator band and the anterior papillary muscle of the tricuspid valve. No case could have more effectively showcased the excellence of our lab and the EP staff. Ablating the PVC required careful and detailed mapping. ICE was critical to ensure that our catheter was in the right position. The staff did what they do in every case — they went above and beyond their call of duty to make sure that the patient was safe and the procedure was effective. Most importantly, they exhibited warmth and caring toward the patient at a time when he was vulnerable and afraid. This was an especially unique circumstance, in that our director of cardiac services was experiencing our EP program from a vastly different perspective. We were in the unusual position of performing a procedure on someone whom we consider to be a member of our family.

Approximately what percentage of ablation procedures is done with cryo vs radiofrequency?

We currently do not use cryo for AF ablation, and rely solely on RF.

What are your techniques for LAA occlusion? Do you have a primary approach?

We currently implant the WATCHMAN device (Boston Scientific) in patients at high risk for stroke and AF, and who are not candidates for long-term oral anticoagulation. 

Do you perform only adult EP procedures or do you also do pediatric cases? 

We treat adults only.

Is your EP lab currently involved in clinical research studies? Which ones?

Yes, we are currently participating in the AMPLATZER Amulet LAA Occluder Trial (Amulet IDE), The Role of Electrophysiology Testing in Survivors of Unexplained Cardiac Arrest (EPS ARREST), Stroke AF trial (Medtronic), AF Fluoro Reduction Study (observational, multicenter), and Barostim Therapy for Heart Failure (BeAT-HF).

Are you ACGME-approved for EP training? 

No, but we have a general cardiology fellowship.

Does your hospital offer a cardiac device support group for patients? 

No, but we are in the process of developing an AF support group.

Does your heart rhythm service offer patients with a suspected inherited arrhythmia a referral to cardiovascular genetics clinic? 


Describe your city or general regional area. How is it unique from the rest of the U.S.?

The islands of Hawai‘i are unique culturally and with respect to population dynamics. In addition to people of Polynesian descent, we have a large contingency of residents who hail from Asia. Although Hawai‘i has the highest life expectancy of any state, we also see premature heart disease in many segments of the population. The Queens Hospital is mission driven, and we strive to uphold the legacy of Queen Emma to ensure that the people of Hawai‘i (and the occasional tourist) receive state-of-the-art care. 

Please tell our readers what you consider special about your EP lab and staff.

Aloha is not just a word, it is a spirit of affection, peace, compassion, and mercy — it is a way of life. Nowhere are these values more apparent than in our EP lab. Whether it’s with each other or with our patients, we try to practice with aloha and kindness at all times.