Interventional Electrophysiology Procedures Research Articles

Current trends in the use of cardiac implantable electronic devices and interventional electrophysiological procedures in the European Society of Cardiology member countries: 2015 report from the European Heart Rhythm Association.

The aim was to provide comprehensive information on the use of cardiac implantable electronic device (CIED) and catheter ablation therapy in the European Society of Cardiology (ESC) area. The European Heart Rhythm Association (EHRA) has collected data on use of invasive arrhythmia managements since 2008. Fifty-one of the 56 ESC member countries provided data for the EHRA White Book 2015. This analysis is based on the current and previous editions of the EHRA White Book. Up-to-date information on procedure rates for the last 5 years together with information on economic resources, reimbursement systems, and training requirements are presented for each country and the five geographical ESC regions. In 2014, the CIED implantation rates per million population were highest in the Western followed by the Southern and Northern European countries. The catheter ablation activity was largest in the Western followed by the Northern and Southern areas. Altogether the procedure rates were lowest in the Eastern European and in the non-European ESC countries. In the European ESC countries, the procedure rates were 3-10 times higher than in the non-European ESC countries. However, in some countries with a relatively low gross domestic product the procedure rates exceeded the average values indicating that utilization of arrhythmia therapies was not driven merely by the economic factors. This analysis indicates that considerable heterogeneity in the availability and utilization of arrhythmia therapies still exist across the ESC area. The data will hopefully aid in directing future activities and promote harmonization of cardiac arrhythmia care in the ESC countries.

Use of fluoroscopy in clinical electrophysiology in Europe: results of the European Heart Rhythm Association Survey.

Despite the advent of non-fluoroscopic technologies, fluoroscopy remains the cornerstone of imaging in most interventional electrophysiological procedures, from diagnostic studies to ablation interventions and device implantation. The purpose of the European Heart Rhythm Association survey was to provide an insight into regulatory policies and physicians' clinical practice when using fluoroscopy during ablation procedures and device implantation. The survey has shown that only 50% of the participating centres worked with low frame rates (3-6 frames per second) and that the left anterior oblique projection, with higher radiation exposure for the physician, is used for nearly every ablation target. Although three-dimensional imaging systems may reduce the radiation exposure, most centres never used these systems for standard ablation procedures and a trend is that non-fluoroscopy technologies are even less frequently used than in 2012, when the use of robotic systems was still rare. Even less costly equipment such as lead gloves, lead glass cabins, or radiation absorbing pads are still not routinely used.

Transcatheter therapies for arrhythmias in patients with complex congenital heart disease

Arrhythmias are responsible for significant morbidity and mortality in patients with complex congenital heart disease (CHD). Pharmacologic antiarrhythmic therapy often proves ineffective or intolerable due to adverse side effect profile in a patient group consigned to lifelong treatment. Interventional electrophysiology procedures have revolutionized arrhythmia management in the CHD population since the introduction of transcatheter ablation in the late 1980s. Tremendous advances in electroanatomic mapping and ablation technology have led to increased procedural success in conjunction with a dramatically reduced risk profile to overcome the challenges of patient size, abnormalities of the intrinsic conduction system, mapping of arrhythmia in complex congenital cardiac malformations and limited access to surgically isolated cardiac chambers. Future interventional electrophysiology innovations are geared to provide further reduction in radiation exposure for the CHD population.

Radiation safety protocol using real-time dose reporting reduces patient exposure in pediatric electrophysiology procedures.

Radiation exposure during pediatric catheterization is significant. We sought to describe radiation exposure and the effectiveness of radiation safety protocols in reducing exposure during catheter ablations with electrophysiology studies in children and patients with congenital heart disease. We additionally sought to identify at-risk patients. We retrospectively reviewed all interventional electrophysiology procedures performed from April 2009 to September 2011 (6 months preceding intervention, 12 months following implementation of initial radiation safety protocol, and 8 months following implementation of modified protocol). The protocols consisted of low pulse rate fluoroscopy settings, operator notification of skin entrance dose every 1,000 mGy, adjusting cameras by >5 at every 1,000 mGy, and appropriate collimation. The cohort consisted of 291 patients (70 pre-intervention, 137 after initial protocol implementation, 84 after modified protocol implementation) at a median age of 14.9 years with congenital heart disease present in 11 %. Diagnoses included atrioventricular nodal reentrant tachycardia (25 %), atrioventricular reentrant tachycardia (61 %), atrial tachycardias (12 %), and ventricular tachycardia (2 %). There were no differences between groups based on patient, arrhythmia, and procedural characteristics. Following implementation of the protocols, there were significant reductions in all measures of radiation exposure: fluoroscopy time (17.8 %), dose area product (80.2 %), skin entry dose (81.0 %), and effective dose (76.9 %), p = 0.0001. Independent predictors of increased radiation exposure included larger patient weight, longer fluoroscopy time, and lack of radiation safety protocol. Implementation of a radiation safety protocol for pediatric and congenital catheter ablations can drastically reduce radiation exposure to patients without affecting procedural success.

Practical ways to reduce radiation dose for patients and staff during device implantations and electrophysiological procedures.

Despite the advent of non-fluoroscopic technology, fluoroscopy remains the cornerstone of imaging in most interventional electrophysiological procedures, from diagnostic studies over ablation interventions to device implantation. Moreover, many patients receive additional X-ray imaging, such as cardiac computed tomography and others. More and more complex procedures have the risk to increase the radiation exposure, both for the patients and the operators. The professional lifetime attributable excess cancer risk may be around 1 in 100 for the operators, the same as for a patient undergoing repetitive complex procedures. Moreover, recent reports have also hinted at an excess risk of brain tumours among interventional cardiologists. Apart from evaluating the need for and justifying the use of radiation to assist their procedures, physicians have to continuously explore ways to reduce the radiation exposure. After an introduction on how to quantify the radiation exposure and defining its current magnitude in electrophysiology compared with the other sources of radiation, this position paper wants to offer some very practical advice on how to reduce exposure to patients and staff. The text describes how customization of the X-ray system, workflow adaptations, and shielding measures can be implemented in the cath lab. The potential and the pitfalls of different non-fluoroscopic guiding technologies are discussed. Finally, we suggest further improvements that can be implemented by both the physicians and the industry in the future. We are confident that these suggestions are able to reduce patient and operator exposure by more than an order of magnitude, and therefore think that these recommendations are worth reading and implementing by any electrophysiological operator in the field.

3D Real-Time Intracardiac Echocardiographic Visualization of Atrial Structures Relevant to Atrial Fibrillation Ablation

cardiac imaging is critical for the success of interventional electrophysiological procedures. Fluoroscopy is highly beneficial for real-time catheter visualization, but it uses ionizing radiation and fails to provide detailed cardiac anatomy. Magnetic resonance imaging and computed tomography

Outcomes of interventional electrophysiology in children under 2 years of age

Despite the increasing utilisation of interventional electrophysiology in adults and older children with arrhythmias, there are few data reflecting the safety and efficacy of this procedure in the age group under 2 years. We describe our experience in assessing the efficacy and safety with this group of children. We undertook a retrospective review of all infants under 2 years of age who underwent an interventional electrophysiology procedure between 1995 and 2009 to determine indications, procedural details, short- and long-term success, and complication rate. A total of 23 interventional electrophysiology procedures were performed in 17 patients initially under 2 years of age. Of these, three patients had congenital heart disease. The most common indication was arrhythmia resistant to pharmacological agents (59%), with the remaining cases being arrhythmia complicated by cardiovascular instability (41%). There was initial success in 15 patients after the first procedure, with early recurrence in four. Following six repeat procedures, there was long-term success in 15 patients (88%), with three repeat procedures being performed after 2 years of age. There was one non-procedural death related to persisting arrhythmia. There were three minor complications. In one patient, cryotherapy was used successfully. The interventional electrophysiology procedure is a viable therapeutic option in infants under 2 years with arrhythmia resistant to other conventional medical management.

Real-time magnetic resonance guidance of interventional electrophysiology procedures with passive catheter visualization and tracking

One of the key problems in interventional electrophysiology (EP) today is the inability to generate sufficient soft tissue contrast for intraprocedural visualization of the myocardium and the surrounding tissue by using conventional imaging techniques. Intraprocedural magnetic resonance imaging (MRI) has been identified as a potential solution to address this weakness of conventional EP; however, clinical adoption of MR-guided EP requires the development of EP devices that are both fully MR functional and MR safe at the same time.

Impact of Relaxation Training on Patient-Perceived Measures of Anxiety, Pain, and Outcomes after Interventional Electrophysiology Procedures

Electrophysiology procedures vary in invasiveness, duration, and anesthesia utilized. While complications are low and efficacy high, cases are elective and patient experiences related to anxiety, pain, and perceived outcomes are not well studied. We sought to determine if a 30-minute audio compact disc (CD) that teaches relaxation techniques and wellness perception prior to an elective procedure impacts validated measures of anxiety, pain, and procedural outcomes. Sixty-one patients were randomly assigned to a control group (CG) (N(CG) = 31) or interventional group (IG) (N(IG) = 30). Both groups answered a baseline Hospital Anxiety and Depression Scale (HADS-A) survey consisting only of anxiety assessment questions. The IG listened to the CD the night prior to their procedure. Heart rate and blood pressure were monitored on admission and prior to the procedure. Postprocedure, both groups completed two HADS-A surveys as well as two Patient Experience Surveys (PES). There was no statistical difference in the demographics and the rate of procedural complications between the groups. The statistical significance of our data was determined using a Student's t-test and χ(2) test. At baseline, both groups had equal amounts of anxiety prior to their procedures (P = 0.2). The patients in the IG had lower systolic blood pressures during admission and prior the administration of analgesics in comparison to the CG. Postprocedure, results from administering the HADS-A demonstrated that the IG had 33% lower anxiety (P = 0.02) than CG patients. The implementation of basic relaxation teaching techniques prior to planned electrophysiology procedures lowers systolic blood pressure and postprocedural anxiety.

Prevalence and Risk Factors for Cervical and Lumbar Spondylosis in Interventional Electrophysiologists

The volume and complexity of interventional electrophysiology procedures have increased greatly over the last 20 years. Anecdotal reports from Canada and elsewhere have suggested an important prevalence of neck and back problems in interventional electrophysiologists. To quantify the scope of neck and back problems, we surveyed 70 interventional electrophysiologists in Canada using an electronic survey with in person and email reminders. We also surveyed an age- and gender-matched group of noninterventional cardiologists. We received responses from a total of 58 of 70 interventional electrophysiologists (response rate 82.8%). There was a significantly higher prevalence of cervical spondylosis among electrophysiologists compared to matched noninterventional cardiologists (20.7% compared to 5.5%, P = 0.033). There was a trend for increased prevalence of lumbar spondylosis (25.9% compared to 16.7%, P = 0.298). Among electrophysiologists, those with cervical spondylosis were older (49.83 ± 10.48 years compared to 44.57 ± 9.20, P = 0.092) and had worked in the specialty for longer in comparison to unaffected physicians (19.67 ± 10.06 years compared to 13.37 ± 8.97 years, P = 0.039). All other variables including gender, height, weight, BMI, type of lead, weekly average lead time, and % of time standing in electrophysiology laboratory were not different. On multivariable analysis there were no independent predictors of disease. There is a significant increased prevalence of cervical spondylosis among interventional electrophysiologists. Programs to improve ergonomics and minimize time spent wearing lead are needed. The same vigilance that is used to ensure radiation safety in the laboratory should be applied to create ergonomic safety.

What an emergency physician needs to know about acute care of cardiac arrhythmias

The treat of cardiac arrhythmias has been studied extensively in the last decades. There has been a major shift in antiarrhythmia treatment from drugs to interventional electrophysiological procedures and implantable devices. Published data indicate that for long-term treatment of arrhythmias, non-pharmacological treatment is more effective than drugs in many patients. Similarly, the overhelming success of radiofrequency catheter ablation of supraventricular tachycardias has almost eliminated the need for chronic drug treatment. Today, catheter ablation plays an increasingly important role in the prevention of atrial fibrillation recurrences. However, in the emergency room or in the intensive care unit, drug treatment remains the gold standard for the treatment of cardiac arrhythmias. Arrhythmias are very common in emergency medicine, occurring in 12% to 20% of all patients in an intensive care unit and there is great need for good diagnostic and therapeutic algorithms to aid the emergency physician dealing with patients suffering from arrhythmias

Impact of Relaxation Training on Measures of Anxiety, Pain, and Patient Perceived Outcomes after Interventional Electrophysiology (EP) Procedures

Impact of Relaxation Training on Measures of Anxiety, Pain, and Patient Perceived Outcomes after Interventional Electrophysiology (EP) Procedures

Electroanatomic Mapping of the Left Ventricle in a Porcine Model of Chronic Myocardial Infarction With Magnetic Resonance–Based Catheter Tracking

X-ray fluoroscopy constitutes the fundamental imaging modality for catheter visualization during interventional electrophysiology procedures. The minimal tissue discriminative capability of fluoroscopy is mitigated in part by the use of electroanatomic mapping systems and enhanced by the integration of preacquired 3-dimensional imaging of the heart with computed tomographic or magnetic resonance (MR) imaging. A more ideal paradigm might be to use intraprocedural MR imaging to directly image and guide catheter mapping procedures. An MR imaging-based electroanatomic mapping system was designed to assess the feasibility of navigating catheters to the left ventricle in vivo using MR tracking of microcoils incorporated into the catheters, measuring intracardiac ventricular electrograms, and integrating this information with 3-dimensional MR angiography and myocardial delayed enhancement images to allow ventricular substrate mapping. In all animals (4 normal, and 10 chronically infarcted swine), after transseptal puncture under fluoroscopic guidance, catheters were successfully navigated to the left ventricle with MR tracking (13 to 15 frames per second) by both transseptal and retrograde aortic approaches. Electrogram artifacts related to the MR imaging gradient pulses were successfully removed with analog and digital signal processing. In all animals, it was possible to map the entire left ventricle and to project electrogram voltage amplitude maps to identify the scarred myocardium. It is possible to use MR tracking to navigate catheters to the left ventricle, to measure electrogram activity, and to render accurate 3-dimensional voltage maps in a porcine model of chronic myocardial infarction, completely in the MR imaging environment. Myocardial delayed enhancement guidance provided dense sampling of the proximity of the infarct and accurate localization of complex infarcts.

Real-Time Three-Dimensional Transesophageal Echocardiography for Guiding Interventional Electrophysiology: Feasibility Study

At present, there are limited methods of acquiring three-dimensional visualization of cardiac structure and function in real-time during interventional electrophysiology procedures. Images acquired for integration of computerized tomography and magnetic resonance imaging with electroanatomic mapping systems are static and are obtained earlier in time. The purpose of this study was to test the feasibility of real-time three-dimensional transesophageal echocardiography for the guidance of interventional electrophysiological studies. A matrix array transducer with 504 channels operating at 5 MHz in a 1 cm diameter steerable esophageal probe was used in conjunction with a scanner capable of real-time 3D scanning of pyramidal volumes from 65 degrees to 120 degrees at rates up to 30 volumes per second. This device has a spatial resolution of approximately 3 mm at 5 cm depth. The authors acquired real-time three-dimensional images of anatomic landmarks of value for electrophysiological procedures in five closed chest canines. Real-time, three-dimensional ultrasound imaging was also used for visualization and guidance of interventional catheter devices within the canine heart. Real-time three-dimensional images of the atria, pulmonary veins, and coronary sinus were acquired. Real-time 3-D color flow Doppler was employed to confirm patency. Multiple image planes of image volumes and rendered views were used to track catheter position and orientation. Images of left veno-atrial junctions have been confirmed by dissection. This study has demonstrated the feasiblity of using real-time three-dimensional transesophageal echocardiography for guiding interventional electrophysiology. The technology has the potential to fill a niche as an adjunct modality for cost-effective real-time interventional guidance and assessment, providing catheter and pacing lead visualization simultaneously with functional volumetric cardiac imaging.

Radiation Peak Skin Dose to Risk Stratify Electrophysiological Procedures for Deterministic Skin Damage

Ionising radiation is has the potential to cause harm both by increasing the probability future malignancy (stochastic mechanisms) and by direct physical injury (deterministic mechanisms). Several measures have been developed to quantify radiation exposure during a procedure and cardiologists usually refer to fluoroscopic screening time (FST). FST, however, has limitations for predicting deterministic injury which is directly dependant on peak skin dose (PSD). We compared FST to PSD for a range of interventional cardiac electrophysiology procedures. All patients undergoing electrophysiology procedures during a 2-month period in our institution were studied. Demographic details, nature of procedure, FST and PSD were measured. The FST to PSD ratio was calculated and compared between patient and procedural factors. 67 procedures on patients (23 female) with body mass index (BMI) of 28 (SD 5) Kg/m2 were studied. Screening times ranged from 0.2 to 96.6 min (median 11.2). PSD ranged from <0.1 to 1108 mGy (median 141). There was a positive correlation between PSD to FST ratio and BMI (r = 0.59, p < 0.001). The PSD to FST ratio was higher in cardiac resynchronization therapy (CRT) devices than single or dual chamber ICDs (p = 0.002). FST is not a reliable predictor of deterministic skin injury and in high-risk procedures such as CRT devices and those on individuals of high BMI PSD should be measured.