Advances in HF Management

In a new article, Tobias Schmidt, MD and colleagues from Asklepios Klinik St. Georg in Hamburg, Germany, describe a case and the hemodynamic results after Parachute® Ventricular Partitioning Device (CardioKinetix, Inc.) implantation in a small subset of patients referred for heart failure to their institution. The Parachute® is a percutaneous ventricular restoration device that effectively excludes damaged heart muscle, thereby leading to an isolation of the non-functional muscle from the functional part. The investigational device is currently available in four sizes: 65 mm, 75 mm, 85 mm and 95 mm. It is distributed with a guide catheter (available in 14 Fr and 16 Fr) and a delivery system. The authors discuss that the Parachute® device was successfully implanted in seven out of eight patients between September 2012 and March 2013. Their data adds evidence to the PARACHUTE study, which demonstrated the ventricular partitioning device to be relatively safe and of potential benefit in patients with heart failure due to prior anterior myocardial infarction. The authors also provided video content demonstrating Parachute® implantation, including preimplantation levocardiography, device positioning, and device opening with balloon dilatation.

In EP Lab Digest®’s March 2013 issue, S.A. Hussain, MD and M.A. Siddiqui, MD from Sinai-Grace Hospital in Detroit, Michigan, provide a review on the impact and latest clinical recommendations of CRT on the management of systolic heart failure. They also discuss the impact of drug therapy on heart failure. They write that in spite of significant improvements in our understanding and treatment of heart failure, mortality rates tend to be high and patients are frequently readmitted to the hospital.

In 2011, Chris Atherton, RN, BSN, MPA and Director of EP Services at Indiana University Health LaPorte Hospital, wrote about their collaborative approach to heart failure care in patients with CRT-D devices at a small community hospital. Their staff share a common goal to decrease readmissions from heart failure and to provide a better quality of life for their patients with heart failure. They discuss the implementation of their collaborative approach, and write that their results have been comparable to those of the major medical centers and teaching institutions. They attribute the success of their remote heart failure monitoring program to the collaboration between their heart failure and EP teams.

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Featured Case Series: The Convergent Procedure

Recently we published a two-part case series on experiences with the convergent procedure.

In our May 2013 issue of EP Lab Digest®, William Belden, MD and Robert Moraca, MD, Director of Thoracic, Aortic and Arrhythmia Surgery, at Allegheny General Hospital in Pittsburgh, Pennsylvania, described a convergent ablation performed in July 2012 in their combined EP/convergent surgical suite. Epicardial posterior left atrial (LA) ablation was performed first by cardiothoracic surgeon Dr. Moraca using a subxiphoid, thorascopic, transdiaphragmatic approach. Radiofrequency (RF) ablation was performed between the left and right pulmonary veins using a 3 cm unipolar ablation catheter. A standard catheter-based PVI was then performed by electrophysiologist Dr. Belden immediately after the epicardial posterior LA ablation was completed. Endocardial LA voltage mapping confirmed extensive posterior LA ablation. Electrogram-guided PVI was then performed using a circular mapping catheter and an irrigated RF ablation catheter. Conversion to sinus rhythm occurred with isolation of the final pulmonary vein. The patient tolerated the procedure without complication. Nine-month follow-up after the procedure showed normal sinus rhythm, and the patient has reported a dramatic improvement in his exercise capacity and quality of life. They conclude that their experience at Allegheny General Hospital with the convergent procedure has been very favorable as depicted in this case as well as many other similar cases.

In the following June 2013 issue, authors M. Clive Robinson, MD, FRACS and colleagues from the CT Cardiac Arrhythmia Center at Bridgeport Hospital in Bridgeport, Connecticut, presented a review of their experience with the convergent hybrid procedure and, in particular, their technique of extended posterior left atrial wall ablation, and its role in treating cases of advanced atrial fibrillation (AF) with severely enlarged left atrias. Rather than the usual ablation lines that are placed along the roof or variably on the perimeter of the posterior left atrium, their method is expanded so as to confluently and directly ablate and debulk the AF mechanisms of the atrial substrate. Between June 2011 and April 2013, 42 patients — 57% (24/42) persistent AF patients and 43% (18/42) longstanding persistent AF patients — received the convergent procedure at Bridgeport Hospital. Of the 42 patients who received the convergent procedure, 6 patients were still within the blanking period at the time of publication. However, of the 36 patients who were past the blanking period, 89% (32/36) are now in sinus rhythm (SR), and 69% (25/36) are in SR and off antiarrhythmic drug therapy, with an average follow-up of 13 months. The authors write that the results appear to validate this procedure in AF patients who are otherwise excluded from intervention or for whom poor outcomes have been likely.

Genetic Testing for Arrhythmias

In their June 2013 article in EP Lab Digest®, Monica Y. Lo, MD and Richard Wu, MD from the University of Texas Southwestern Medical Center discuss how genetic testing can play an important role in the diagnosis and management of inherited arrhythmogenic diseases. At their institution in Dallas, patients with suspected inherited arrhythmogenic diseases are referred to the clinical genetics clinic. There they are seen by geneticists and genetic counselors to discuss the appropriateness and implications of genetic testing. Typically a sample of blood is sent for next-generation sequencing, which offers several multi-gene testing panels. If a mutation(s) is identified, mutation-specific testing is offered to first-degree relatives. Tests generally take about 6-8 weeks to complete. Post-testing counseling is also done to discuss test results.

In October 2012, Heather MacLeod, MS CGC, Genetic Counselor and Cardiac Team Leader, InformedDNA, specifically outlined the role of genetic counselors in heart rhythm disorders. In her article, she explained that genetic counselors are health professionals with specialized graduate degrees and experience in the areas of medical genetics and counseling; there are approximately 2,700 genetic counselors working in the US today. She noted that genetic counselors are experts in the nuances of which tests and testing platforms are available, and can recommend the most appropriate testing based on the diagnosis of concern and insurance coverage. Genetic counselors can also provide supportive resources to their patients in adjustment to their results.

Michael H. Gollob, MD, from the Inherited Arrhythmia Clinic and Arrhythmia Research Laboratory at the University of Ottawa Heart Institute, contributed an article in March 2012 on genetic testing for atrial fibrillation. Clinical genetic testing for the currently known culprit genes for atrial fibrillation are now commercially available. In recent years, genetics research has led to a surge in the identification of genetic culprits responsible for lone, familial, or sporadic lone atrial fibrillation. Eight genes are currently recognized as a cause of sporadic or familial atrial fibrillation.

In February 2011, Janet Reina, CCT, CVT, MA described how the Cleveland Clinic in Florida has been changing the way they treat certain arrhythmias with the conventional treatment of these diseases. In the article she provided some of the most familiar gene mutation codes in genetic testing. She recommends that the youngest, most severely affected family member should be tested first.

Cryoablation for AF

In the June 2013 issue of the Journal of Invasive Cardiology, Todd J. Cohen, MD and colleagues from Winthrop University Hospital presented their early experience with Medtronic’s Arctic Front® Cardiac CryoAblation balloon catheter compared to radiofrequency (RF) catheter ablation. Their findings showed comparable outcomes with cryoablation and RF ablation. The immediate success rate was 93.5% with RF catheter ablation and 96.7% with cryoablation (P=NS), with no significant differences in complications. Their study also showed no decrease in procedural or fluoroscopy times with this early experience. The authors note that the cryoablation procedure did result in a 30% additional cost to the hospital procedure, but this cost increment could be reduced by streamlining the cryoablation procedure and using a lesser number of ancillary catheters. They conclude that use of cryoablation and RF catheter ablation can be beneficial in treating atrial fibrillation (paroxysmal and persistent).

Dr. Cohen, Editor-in-Chief Emeritus of EP Lab Digest®, is a regular contributor to EP Lab Digest® and has a featured blog on the website as well. His recent articles in EP Lab Digest® include “Cardiac Syncope Versus Seizure: The Value of the EP Consult” from the February 2013 issue, and “Externalized Conductor of a St. Jude Medical Riata Defibrillator Lead: Case Report and Review of the Literature” from the April 2013 issue. A complete listing of his blogs is also available.

Understanding Twiddler’s Syndrome

In the June 2013 issue of EP Lab Digest®, Eleonore Werner, MD and colleagues provide a case study of a 76-year-old female who presented to Maine Medical Center after a wireless monitor triggered an alert, revealing evidence of an ICD lead fracture. On hospital day 3, the patient underwent successful right ventricle lead revision. During the procedure, visual inspection revealed that the device moved quite easily in its pocket and there was twisting consistent with Twiddler’s Syndrome. This syndrome, first described in 1968, refers to permanent malfunction of a pacemaker secondary to manipulation of the pulse generator within its pocket. This leads to ineffective ventricular pacing due to displacement of the leads. It is hypothesized that it is the location of the generator that can induce subconscious manipulation. Dr. Werner noted that this patient tolerated the procedure without any complications and was discharged on day 4 with close follow-up.

We’ve explored other cases of Twiddler’s Syndrome in previous issues of EP Lab Digest®. In July 2012, Jeffrey Hirsh, MD from the University of Tennessee Medical Center described how his practice had encountered 12 cases of suspected or confirmed Twiddler’s Syndrome among 2,357 implanted devices between 2002 and 2010. This syndrome was seen in both pacemaker and ICD patients; several patients twiddled multiple times. Six of their patients were treated by using the AIGISrx Antibacterial Envelope (TYRX, Inc.); these patients required no further procedures. Dr. Hirsh’s article examines one of the patients from this series.

In February 2012, author Shawn Balaschak, RN, BSN, MS from St. Clair Hospital also presented a brief case study on a patient with Twiddler’s Syndrome (Figure 1). He wrote that this phenomenon occurs in only 0.07%–1.7% of implants. Symptoms can include decreased heart rate, device malfunction, twitching of the arm, chest, abdomen, and stomach area. He also noted that patients with psychotic disorders or patients with large pacemaker pockets are more prone to experience Twiddler’s Syndrome.

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Have you encountered Twiddler’s in your EP cases? Let us know!

MR Conditional Technology

In the June 2013 issue of EP Lab Digest®, author Atul Verma, MD provides details on a patient at Southlake Regional Health Centre in Ontario, Canada, who had specific clinical circumstances requiring an implantable cardioverter-defibrillator (ICD) as well as an ongoing need for MRI imaging. He shares how this problem was addressed by the use of an MRI-conditional ICD system. At Southlake, they have been implanting MRI-conditional pacemakers for about one year, and have now begun implanting MRI-conditional CIEDs.

In a previous issue, Luca Santini, MD, PhD et al from San Filippo Neri Hospital in Rome, Italy discussed how MRI has become the imaging modality of choice across a broad range of indications over the last few years. More recently, MR imaging has also been applied successfully to evaluate myocardial structure, wall motion, and perfusion. In February 2012, Dr. Santini and colleagues addressed MR conditional technology at their institution. They conclude that the ability to use MR scans is extremely important, and that new MR conditional ICD technology represents an important breakthrough for patients needing ICDs.

On a related note, Nassir F. Marrouche, MD, Executive Director of the University of Utah’s Comprehensive Arrhythmia Research & Management Center (CARMA), Director of Electrophysiology Laboratories, and Director of the Atrial Fibrillation Program at the University of Utah School of Medicine, Division of Cardiology, contributed a blog to EP Lab Digest® in 2011 about the advances in MRI technology and techniques. To gain insights into how the use of advanced MRI is changing the clinical treatment of atrial fibrillation, he spoke with Eugene Kholmovski, PhD, Assistant Professor at the Utah Center for Advanced Imaging Research. Dr. Kholmovski noted that CARMA opened the first integrated EP-MRI clinical and research lab in North America, and that a lot of exciting research was being done to enable ablation procedures in the MRI suite.