Komandoor Srivathsan

Safety of capsule endoscopy in patients with pacemakers

BACKGROUND Capsule endoscopy, a new technology, allows visualization of the entire small intestinal mucosa. The main indication for capsule endoscopy at present is the evaluation of GI bleeding of obscure origin. Studies to date suggest that capsule endoscopy is safe and is associated with few adverse events. One concern, which has not been studied, is the potential effect of the capsule on cardiac pacemakers and other electromedical devices. The primary aims of this study were to evaluate the safety of capsule endoscopy in patients with cardiac pacemakers who are being evaluated for GI bleeding of obscure origin and to determine whether pacemakers have any effect on the images captured by the capsule endoscope. METHODS Patients with cardiac pacemakers referred for evaluation of GI bleeding of obscure origin were entered into the study. Before the procedure, an electrocardiogram was obtained, and pacemaker functions were checked. Capsule endoscopy was performed in a hospital setting to allow closer monitoring, instead of the outpatient clinic, which is our routine. Cardiac rhythm was assessed simultaneously during capsule endoscopy with a Holter monitor. Post-procedure pacemaker function was again checked for any disturbance. When the capsule endoscopy studies were reviewed, observations were made with particular reference to technical difficulty or interference with imaging. OBSERVATIONS Five consecutive patients (4 men, 1 woman; mean age, 73 years, range 56-92 years) with cardiac pacemakers were studied. In all patients, the indication for capsule endoscopy was GI bleeding of obscure origin. A cardiologist and pacemaker nurse specialist reviewed the Holter monitor recordings and evaluated pacemaker function after the procedure for each patient. No arrhythmia or other adverse cardiac event was noted during capsule transmission. No pacemaker-induced interference on the capsule endoscopy images was observed. CONCLUSIONS Capsule endoscopy appears to be safe in patients with cardiac pacemakers and does not appear to be associated with any significant adverse cardiac event. Pacemakers do not interfere with capsule imaging.

Safety of wireless capsule endoscopy in patients with implantable cardiac defibrillators.

OBJECTIVES:Wireless video capsule endoscopy (CE) is a new technology that allows visualization of the entire small intestinal mucosa. It is indicated for the evaluation of obscure gastrointestinal bleeding (OGIB) and other disorders of the small intestine. Studies to date suggest that CE is safe and associated with few adverse events. A concern, which has not been studied, is the potential effect of CE on implanted cardiac devices such as implantable cardiac defibrillators (ICD) and other electromedical devices. We previously found CE to be safe in patients with cardiac pacemakers. The primary aim of this study was to evaluate the safety of CE in patients with ICDs who were being evaluated for OGIB. In addition, a secondary aim of the study was to determine whether ICDs had any effect on the images captured by CE.METHODS:Patients referred for the evaluation of OGIB and who also had an ICD were enrolled into the study after informed consent. Five consecutive patients (four females and one male; mean age: 72 yr; range: 60–81 yr) with ICDs were studied. All patients had transvenous endocardial ICDs located in the chest. Prior to CE, patients had a baseline electrocardiogram (ECG) and ICD interrogation. Thereafter, CE was performed in a hospital setting with telemetry monitoring performed simultaneously. A post-procedure ICD interrogation was carried out to evaluate changes in programmed parameters. A cardiologist and ICD nurse specialist together reviewed both the telemetry monitor and the post-procedure ICD interrogation on each patient. When CE studies were reviewed, observations pertaining to technical difficulties and interference with video imaging were documented.RESULTS:No arrhythmia or other adverse cardiac events were noted during capsule transmission. No interference by the ICD on the CE video images was seen.CONCLUSIONS:CE was performed safely in these five patients with ICDs, and was not associated with any adverse cardiac events. ICDs also do not appear to interfere with video capsule imaging.

Differentiating Atrioventricular Nodal Reentrant Tachycardia from Junctional Tachycardia: Novel Application of the Delta H-A Interval

Introduction: Junctional tachycardia (JT) and atrioventricular nodal reentrant tachycardia (AVNRT) can be difficult to differentiate. Yet, the two arrhythmias require distinct diagnostic and therapeutic approaches. We explored the utility of the delta H‐A interval as a novel technique to differentiate these two tachycardias.

2017 HRS expert consensus statement on cardiovascular implantable electronic device lead management and extraction

Fred M. Kusumoto, MD, FHRS, FACC, Chair, Mark H. Schoenfeld, MD, FHRS, FACC, FAHA, CCDS, Vice-Chair, Bruce L. Wilkoff, MD, FHRS, CCDS, Vice-Chair, Charles I. Berul, MD, FHRS, Ulrika M. Birgersdotter-Green, MD, FHRS, Roger Carrillo, MD, MBA, FHRS, Yong-Mei Cha, MD, Jude Clancy, MD, Jean-Claude Deharo, MD, FESC, Kenneth A. Ellenbogen, MD, FHRS, Derek Exner, MD, MPH, FHRS, Ayman A. Hussein, MD, FACC, Charles Kennergren, MD, PhD, FETCS, FHRS, Andrew Krahn, MD, FRCPC, FHRS, Richard Lee, MD, MBA, Charles J. Love, MD, CCDS, FHRS, FACC, FAHA, Ruth A. Madden, MPH, RN, Hector Alfredo Mazzetti, MD, JoEllyn Carol Moore, MD, FACC, Jeffrey Parsonnet, MD, Kristen K. Patton, MD, Marc A. Rozner, PhD, MD, CCDS, Kimberly A. Selzman, MD, MPH, FHRS, FACC, Morio Shoda, MD, PhD, Komandoor Srivathsan, MD, Neil F. Strathmore, MBBS, FHRS, Charles D. Swerdlow, MD, FHRS, Christine Tompkins, MD, Oussama Wazni, MD, MBA

Capsule Endoscopy in Patients with Implantable Electromedical Devices is Safe

Background and Study Aims. The presence of an implantable electromechanical cardiac device (IED) has long been considered a relative contraindication to the performance of video capsule endoscopy (CE). The primary aim of this study was to evaluate the safety of CE in patients with IEDs. A secondary purpose was to determine whether IEDs have any impact on images captured by CE. Patients and Methods. A retrospective chart review of all patients who had a capsule endoscopy at Mayo Clinic in Scottsdale, AZ, USA, or Rochester, MN, USA, (January 2002 to June 2010) was performed to identify CE studies done on patients with IEDs. One hundred and eighteen capsule studies performed in 108 patients with IEDs were identified and reviewed for demographic data, method of preparation, and study data. Results. The most common indications for CE were obscure gastrointestinal bleeding (77%), anemia (14%), abdominal pain (5%), celiac disease (2%), diarrhea (1%), and Crohns disease (1%). Postprocedure assessments did not reveal any detectable alteration on the function of the IED. One patient with an ICD had a 25-minute loss of capsule imaging due to recorder defect. Two patients with LVADs had interference with capsule image acquisition. Conclusions. CE did not interfere with IED function, including PM, ICD, and/or LVAD and thus appears safe. Additionally, PM and ICD do not appear to interfere with image acquisition but LVAD may interfere with capsule images and require that capsule leads be positioned as far away as possible from the IED to assure reliable image acquisition.

Advances in management of premature ventricular contractions

Premature ventricular complexes (PVCs) are a common occurrence in clinical practice. The clinical presentation may range from asymptomatic to left ventricular (LV) dysfunction with congestive heart failure. The decision to suppress PVCs is largely based on the presence of symptoms, interference with other therapy (e.g., cardiac resynchronization therapy), or suspicion of PVC-mediated cardiomyopathy. Catheter ablation has emerged as a safe and effective option for the treatment of frequent PVCs. Careful attention to PVC characteristics on surface electrocardiogram has proven useful for the initial localization of the ectopic focus, which may then serve as a guide to procedural planning. The point of interest is often identified with activation mapping, and the ablation site can be further defined with pace mapping techniques. Clinical experience with PVC ablation has been successful in ≥80 % of cases, and the literature reports multiple cases of marked improvement in LV function after eradicating the culprit ectopic focus in patients with PVC-mediated cardiomyopathy.

Radiotherapy-induced pacemaker and implantable cardioverter defibrillator malfunction.

It is well known that ionizing radiation can interfere with circuits in permanent pacemakers and implantable cardioverter defibrillators. Contemporary implantable cardiac devices use complementary metal-oxide silicon in combination with other very sensitive transistors. These sensitive components are especially susceptible to electromagnetic and ionizing radiation, which can potentially cause permanent damage. Electromagnetic interference is, in general, a transient phenomenon. Radiologic imaging tests have been implicated in rare cases of implantable device dysfunction and these events have been mostly transient. The American Association of Physicists in Medicine last published recommendations regarding irradiation of pacemakers in 1994. This publication is outdated and may not be pertinent for the current technology used both in the field of artificial cardiac pacing and defibrillation and in the field of radiation oncology. Updated guidelines are definitely needed.

T-wave oversensing and inappropriate shocks: a case report

A 27-year-old male with congenital long QT syndrome, SCN5A mutation experienced recurrent inappropriate exercise-related implantable cardioverter defibrillator (ICD) shocks. This device showed T-wave oversensing with double, which lead to these device discharges. Dynamic T-wave oversensing was reproducibly provoked at exercise treadmill testing and was confirmed as the mechanism leading to double counting. The insertion of a new pacing and sensing lead with increased R-wave amplitude did not solve the problem. Exchanging the existing ICD generator with one capable of automatic sensitivity control (Biotronik, Lexos DR, Biotronik, Berlin, Germany) completely eliminated T-wave oversensing and inappropriate shocks.

Effect of pacing method on risk of sudden death after atrioventricular node ablation and pacemaker implantation in patients with atrial fibrillation

BACKGROUND Sudden death may occur after radiofrequency catheter ablation of the atrioventricular node (AVN) and permanent pacemaker implantation. It is unclear whether a faster initial heart rate with gradual rate reduction decreases the risk of sudden death. OBJECTIVE To evaluate the effects of initial pacing at a faster rate after AVN ablation, with a gradual rate decrease over 3 months, on the rate of sudden death in patients with atrial fibrillation. METHODS We compared the rate of likely or possible procedure-related sudden death in 2 groups of patients who had AVN ablation and pacemaker implantation. The study cohort was treated between January 2005 and December 2009, and pacemakers were programmed to a lower rate of 90 beats/min after the procedure, with a monthly decrement of 10 beats/min until 60 beats/min was reached. The control group was treated between July 1990 and December 1998 when pacemakers were programmed to a lower rate of 60 beats/min immediately after ablation. RESULTS The study cohort included 520 patients (mean age 73.6 ± 10.3 years), and the control cohort comprised 334 patients (mean age 68.1 ± 1.1 years). Sudden death deemed likely or possibly related to ablation and pacemaker implantation occurred in 1 patient in the study cohort (0.2%) and in 7 patients (2.1%) in the control group (P = .007). CONCLUSIONS Sudden death was significantly decreased in the study cohort compared to controls. The faster lower pacing rate immediately after AVN ablation with a gradual decrease is a plausible mechanism for the improved clinical outcome.

Pneumopericardium and pneumothorax contralateral to venous access site after permanent pacemaker implantation

A 77-year-old female underwent implantation of a left-sided dual chamber permanent pacemaker for symptomatic bradycardia with active fixation leads. Eight hours after the procedure, the patient complained of shortness of breath and was found to have a 30% right pneumothorax on chest X-ray. Immediately, a chest tube was inserted, promptly relieving the symptoms. A CT scan of the chest revealed extrusion of the helix of the screw-in atrial lead, through the wall of the right atrial appendage. The helix was abutting a bulla in the right lung, the likely cause for pneumothorax and pneumopericardium. The atrial lead was explanted without incident.