Understanding WPW Syndrome

In a new issue, Hayrullah Alp, MD and colleagues from Necmettin Erbakan University, Meram School of Medicine Hospital, present a case of an infant referred to their clinic with severe Ebstein’s anomaly, ventricular communications, and Wolff-Parkinson-White (WPW) syndrome. EP Lab Digest® has featured several articles on WPW syndrome over the years.

The conduction anomaly known as WPW syndrome affects 0.1 to 0.2% of the population, and can be found in males and females. It can occur at any age, but is most often seen in childhood or in the third or fourth generation of life. Patients can be asymptomatic, have occasional episodes, or have episodes that require RF ablation. In October 2012, Deanne Wilk, RN and Jeffrey L. Williams, MD, MS, FACC, FHRS explained that WPW is one of a classification of preexcitation disorders that have been found to have a genetic component. New research has identified the gene (PRKAG2) with WPW associated with hypertrophic cardiomyopathy and conduction system disease. There may also be a glycogen and ion channel mutation in conjunction with the accessory pathways that are the hallmark of this syndrome. WPW syndrome is in extensive research to identify the components of the genetic mutation and its relation to other disease processes.

This February, Antonio Navarrete, MD, FACC, CCDS and Louis Janeira, MD reported on a case of WPW in a 23-year-old patient with a persistent left superior vena cava (PLSVC), the most frequent congenital thoracic vein abnormality. The patient was referred for catheter ablation of WPW with left-sided accessory pathway for recurrent presyncopal spells due to preexcited atrial fibrillation (AF). The authors wrote that the association between WPW and AF is well known, although the underlying basic mechanism is not totally understood, and that up to 30% of patients with WPW develop AF. In this particular case, Drs. Navarrete and Janeira performed only catheter ablation of WPW, and no further AF was documented in this patient at five-month follow-up (the PLSVC was a potential cause for the AF episodes). They concluded that when AF is documented in WPW patients with PLSVC, it is reasonable to target the accessory pathway as a first-line approach.

For more information on WPW, check out this sampling of other various articles in EP Lab Digest®:
EP 101: What Preexcitation Wrought: Wolff-Parkinson-White
• What Is the Risk of Sudden Cardiac Arrest with a Decremental Atrio-fasicular Pathway?

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LVADs in EP

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In a new case study, Christopher R. Ellis, MD, FACC from Vanderbilt Heart and Vascular Institute in Nashville, Tennessee, discusses how patients with a left ventricular assist device (LVAD) pose unique considerations when considering left-sided ablation procedures. He describes a 48-year-old male patient with a biventricular ICD who had also previously undergone implantation of a HeartMate II (Thoratec Corporation) LVAD in May 2010. When the patient came to the clinic in sustained ventricular tachycardia (VT) at 156 bpm, it was discussed to have the patient undergo possible VT mapping and radiofrequency (RF) ablation. Dr. Ellis writes that RF ablation of sustained VT in patients with the LVAD is feasible, but typically best performed with minimal sedation and a transseptal approach. Also, due to a high rate of underlying conduction system disease in these patients, bundle branch re-entry VT should always be considered as the underlying mechanism, and will typically have a high rate of success with ablation of either the right or left bundle branch.

Mount Sinai Medical Center, which has one of the largest LVAD programs in the U.S., recently announced it was the first medical center in New York City to offer the newly FDA approved HeartMate II® Pocket Controller™ to help its advanced heart failure patients maintain more active lifestyles. Mount Sinai started using LVAD technology in 2006 for advanced heart failure patients. This latest generation controller for the HeartMate II left ventricular assist device is a light-weight external controller about the size of a smart phone that easily fits in a patient’s front pocket and powers the heart to pump. The Pocket Controller is available for new advanced heart failure patients in need who receive HeartMate II as well as for current HeartMate II patients who wish to upgrade their existing system controllers.

Case Studies & Experience from Spectrum Health

In the newest issue of EP Lab Digest®, Bohuslav Finta, MD from West Michigan Heart, Spectrum Health and Meijer Heart Center in Grand Rapids, Michigan shares his initial experience with left atrial appendage closure using the LARIAT Suture Delivery Device (SentreHEART, Inc.). Development of the procedure at Spectrum was approached as a new institutional program; once institutional and divisional agreement on the program was reached, operators took part in a sponsored training program. Dr. Finta writes that to date, the LARIAT procedure has been done in approximately 1,400 patients worldwide, and that in the U.S., more than 40 hospitals have adopted or are in a process of adopting this procedure. Between February and June 2013, LARIAT procedures were performed at Spectrum Health in 10 patients with non-valvular AF. The device was successfully deployed in seven patients. In their opinion, the LARIAT procedure represents significant progress in the management of thromboembolic risk in high-risk, OAC-contraindicated patients. They note that further clinical research is necessary to broaden the indications for the LARIAT.

In our March 2012 issue, we featured a Spotlight Interview with the EP program at Spectrum Health. Their program was started in 1991. At the time of publication, there were five board-certified cardiac electrophysiologists at Spectrum Health and three dedicated EP labs within the cardiac catheterization department. They average about 50 procedures each week; this includes a variety of ablations and device implantations. They write that they are able to perform a volume of procedures that is unparalleled for their program size, and attribute this by utilizing efficient turnaround times.

In another recent article from Spectrum Health, authors Musa I. Dahu, MD and Mathew Jackson, RT(R) contributed a case which revealed a decremental atrio-fasicular pathway. Their case reminds electrophysiologists to risk stratify young patients for lethal and often unforgiving arrhythmias. Clinical data remains lacking, and long-term prospective data is not available to help establish evidence-based guidelines. Therefore, it is important to carefully and individually weigh the risks and benefits of each EP case.

Discussion on Chronotropic Incompetence

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New on EP Lab Live, interventional cardiologist Andrew J. Benn, MD and electrophysiologist Steven Kang, MD, with Cardiovascular Consultants Medical Group, Inc. in Oakland, California, discuss the disease-state, prevalence, diagnosis, treatment, and follow-up of chronotropic incompetence.

Chronotropic incompetence refers to the inability to raise the heart rate with exercise to match metabolic demand. This condition is exceptionally prevalent; Dr. Benn notes that when the Framingham Study looked at men in their 40s, 1 in every 6 was chronotropically incompetent. If diagnosed with chronotropic incompetence, a patient is 2-3 times more likely to have a heart attack or another vascular event. In this taped procedure, Dr. Kang places a dual-chamber INGENIO™ pacemaker (Boston Scientific) in a patient referred by Dr. Benn for chronotropic incompetence.

This activity is sponsored by Boston Scientific. A special thanks goes out to Alta Bates Summit Medical Center for their generosity and expertise in making this video possible.

EP Lab Live is a great resource for electrophysiology lab professionals; take a minute to view our full video library! In addition, please see our related sites at Cath Lab Live and Vascular Live for a complete listing of videos in interventional cardiology and vascular disease management.

mHealth and EP-Related Apps

In a feature interview this month, EP Lab Digest® spoke with Dr. Samuel Sears about his interactive mobile phone ICD Coach app, which was was designed to help ICD recipients cope with and overcome the psychosocial side effects associated with their device. Dr. Sears is a Professor in the Departments of Psychology and Cardiovascular Sciences at East Carolina University and the East Carolina Heart Institute in Greenville, North Carolina; he is also a licensed psychologist in North Carolina and Florida. The ICD Coach app was launched in mid-2012, and is priced at $4.99.

In a recent blog, Dr. Kevin Campbell discussed the growing impact of medical apps, noting that patients, providers, pharma and industry have all become increasingly connected. He writes that ultimately, the use of apps will help to further engage patients and improve care, and that the future of mHealth (mobile health) is clearly with the expanded use of mobile devices. There is still much more to look forward to as we continue into the rest of 2013.

In our February 2011 issue, we also spoke with Dr. David Albert about the AliveCor Heart Monitor, which snaps onto the back of an iPhone (4, 4S and 5) to record, display, store, and transfer single-channel ECG rhythms wirelessly with a corresponding AliveECG app. The AliveCor Heart Monitor is the first FDA-cleared mobile device-based ECG monitor. The Heart Monitor is available in the U.S. for medical professionals and prescribed patients.

What medical apps are you using or prescribing? Share your thoughts!

AF Ablation: Tips for Successful Procedure & Program

New in EP Lab Digest®, Edmund O. Ang, MD describes the efforts to establish a Cardiac Arrhythmia Center and atrial fibrillation (AF) ablation program at St. Luke’s Medical Center-Global City in the Philippines. In the article Dr. Ang provides details on how funding was acquired, how he determined what type of mapping system would be best suited to the needs of their patients, and he discusses the first cases performed. Dr. Ang remarks that it is truly an exciting time to be working in cardiac electrophysiology in the Philippines.

In the November 2012 issue, Carrie Hoefling, RCES and colleagues from OSF Saint Francis Medical Center Campus in Peoria, Illinois, contributed an article on the perspective of technicians and nurses when starting an AF ablation program. During the summer of 2011, an AF ablation program was established at OSF Saint Francis. The authors note that the key to a successful program is understanding what the procedure entails and, most importantly, being prepared for complications if and when they occur. They also stress the importance of communication in helping a new lab to successfully eradicate AF.

Also of note is a recent article from November 2011. Authors Ahmad Abdul-Karim, MD and Sunil Shroff, MD from Heartland Cardiovascular Center, Provena St. Joseph Medical Center in Joliet, Illinois, discussed new techniques in AF ablation as well as provide tips for a successful procedure. For example, they consider the first ablation lesion to be the most important, and they try to resist moving to a new site prematurely. Unnecessary ablation lines should also be avoided. They also suggest that complete pulmonary vein disconnection be confirmed at completion, and is considered the cornerstone of each procedure.

Addressing Cardiac Device Placement

New this month, Dr. Weston W. Whittington and colleagues from the Cavanagh Heart Clinic at Banner Good Samaritan Medical Center in Phoenix, Arizona, introduce a modified axillary implantation approach that has shown improved cosmetic results for patients. They note that the traditional approach utilizes the subclavian vein as the point of access; however, this can often leave visible scars and a protruding device that can deter a patient’s recovery from a psychosocial aspect. Using their proposed method for device implantation, they have found several benefits, including a truncated procedure and fluoroscopy time. Also, entering through the axillary vein rather than the subclavian spares the proximal part of the vein for future re-entry if necessary (e.g., device upgrade). However, the biggest advantage is the aesthetic outcome.

Device placement and body image are especially important concerns for patients with ICDs and pacemakers. In EP Lab Digest®’s September 2012 issue, we spoke with members of the “The Defibril-ladies” ICD patient support group from North Shore Medical Center at Salem Hospital in Salem, Massachusetts. They mentioned recent research on the mammary implant technique, which is placement underneath the arm and behind the breast, which they thought was much better.

Another previous article published in July 2010 addressed ICDs in the young. Authors Ian Law, MD and colleagues from the University of Iowa Children’s Hospital wrote that for those who care for children and young adults with life-threatening heart disease requiring ICD implantation, you become well aware that much of the emotional impact of the ICD occurs after device placement. Although pediatric ICD implants account for less than 1% of devices, this number is growing substantially. They describe that ICD implantation in pediatric patients often results in unique psychosocial issues not typically seen in adults. It also occurs at the time when these young patients are trying to develop social independence and a sense of self. For many, ICD placement leads to fear of peer rejection, altered body image, and concern of inappropriate or appropriate shocks. As they enter into early adulthood, their concerns turn to fear of intimacy, marriage, child-bearing and in general, fear of the unknown. These unique considerations have led the staff at University of Iowa Children’s Hospital to proactively address the psychosocial and physical impact of ICD implantation.