POPDC1 Variants Cause Atrioventricular Node Dysfunction and Arrhythmogenic Changes in Cardiac Electrophysiology and Intracellular Calcium Handling in Zebrafish.

Popeye domain-containing (POPDC) proteins selectively bind cAMP and mediate cellular responses to sympathetic nervous system (SNS) stimulation. The first discovered human genetic variant (POPDC1S201F) is associated with atrioventricular (AV) block, which is exacerbated by increased SNS activity. Zebrafish carrying the homologous mutation (popdc1S191F) display a similar phenotype to humans. To investigate the impact of POPDC1 dysfunction on cardiac electrophysiology and intracellular calcium handling, homozygous popdc1S191F and popdc1 knock-out (popdc1KO) zebrafish larvae and adult isolated popdc1S191F hearts were studied by functional fluorescent analysis. It was found that in popdc1S191F and popdc1KO larvae, heart rate (HR), AV delay, action potential (AP) and calcium transient (CaT) upstroke speed, and AP duration were less than in wild-type larvae, whereas CaT duration was greater. SNS stress by ß-adrenergic receptor stimulation with isoproterenol increased HR, lengthened AV delay, slowed AP and CaT upstroke speed, and shortened AP and CaT duration, yet did not result in arrhythmias. In adult popdc1S191F zebrafish hearts, there was a higher incidence of AV block, slower AP upstroke speed, and longer AP duration compared to wild-type hearts, with no differences in CaT. SNS stress increased AV delay and led to further AV block in popdc1S191F hearts while decreasing AP and CaT duration. Overall, we have revealed that arrhythmogenic effects of POPDC1 dysfunction on cardiac electrophysiology and intracellular calcium handling in zebrafish are varied, but already present in early development, and that AV node dysfunction may underlie SNS-induced arrhythmogenesis associated with popdc1 mutation in adults.

Uremic toxins in chronic kidney disease highlight a fundamental gap in understanding their detrimental effects on cardiac electrophysiology and arrhythmogenesis.

Chronic kidney disease (CKD) and cardiovascular disease (CVD) have an estimated 700-800 and 523 million cases worldwide, respectively, with CVD being the leading cause of death in CKD patients. The pathophysiological interplay between the heart and kidneys is defined as the cardiorenal syndrome (CRS), in which worsening of kidney function is represented by increased plasma concentrations of uremic toxins (UTs), culminating in dialysis patients. As there is a high incidence of CVD in CKD patients, accompanied by arrhythmias and sudden cardiac death, knowledge on electrophysiological remodeling would be instrumental for understanding the CRS. While the interplay between both organs is clearly of importance in CRS, the involvement of UTs in pro-arrhythmic remodeling is only poorly investigated, especially regarding the mechanistic background. Currently, the clinical approach against potential arrhythmic events is mainly restricted to symptom treatment, stressing the need for fundamental research on UT in relation to electrophysiology. This review addresses the existing knowledge of UTs and cardiac electrophysiology, and the experimental research gap between fundamental research and clinical research of the CRS. Clinically, mainly absorbents like ibuprofen and AST-120 are studied, which show limited safe and efficient usability. Experimental research shows disturbances in cardiac electrical activation and conduction after inducing CKD or exposure to UTs, but are scarcely present or focus solely on already well-investigated UTs. Based on UTs data derived from CKD patient cohort studies, a clinically relevant overview of physiological and pathological UTs concentrations is created. Using this, future experimental research is stimulated to involve electrophysiologically translatable animals, such as rabbits, or in vitro engineered heart tissues.

Surgical Strategies for Cardiac Perforation After Catheter Ablation or Electrophysiology Study.

Catheter ablation is a treatment modality which has been increasingly used for cardiac arrhythmias. However, it is not complication-free, and cardiac perforation is one of its most life-threatening complications. As surgery is usually not the first-line treatment for this emergent episode, there were only very few sporadic surgical reports in the literature. This systemic review primarily aims to collect different surgical approaches for catheter-induced cardiac perforation to help surgeons manage this kind of uncommon and critical patients. Of the 452 initially screened articles, 22 studies (38 patients) were included in the systemic review. Of all the included patients, 84% (32/38) were found to have pericardial effusion acutely following catheter-related procedures, and 16% (6/38) experienced delayed-onset episodes. Regarding the surgical procedures, four patients underwent removal of clots only, eight patients underwent suture repair of the left ventricle (LV), nine patients underwent suture repair of the right ventricle (RV), five patients underwent suture repair of the LA, and four patients underwent sutureless repair of the LV and pulmonary vein (LV 1, RV 1, pulmonary vein 1). In addition to repair of perforation sites, the concomitant combined procedures included repair of intercostal vessels (complication of pericardiocentesis) for one patient, cryoablation for two patients, and maze procedure for one patient. For cardiac perforation following catheter ablation or electrophysiology study, although the majority of the patients are treated with pericardiocentesis and medical management at first, cardiovascular surgeons have to prepare to take over if the bleeding is persistent or if the cardiac tamponade is not relieved.

X-ray management in electrophysiology: a survey of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC).

AIMS: Radiation use in medicine has significantly increased over the last decade, and cardiologists are among the specialists most responsible for X-ray exposure. The present study investigates a broad range of aspects, from specific European Union directives to general practical principles, related to radiation management among a national cohort of cardiologists. METHODS AND RESULTS: A voluntary 31-question survey was run on the Italian Arrhythmology and Pacing Society (AIAC) website. From June 2019 to January 2020, 125 cardiologists, routinely performing interventional electrophysiology, participated in the survey. Eighty-seven (70.2%) participants are aware of the recent European Directive (Euratom 2013/59), although only 35 (28.2%) declare to have read the document in detail. Ninety-six (77.4%) participants register the dose delivered to the patient in each procedure, in 66.1% of the cases both as fluoroscopy time and dose area product. Years of exposition (P = 0.009) and working in centers performing pediatric procedures (P = 0.021) related to greater degree of X-ray equipment optimization. The majority of participants (72, 58.1%) did not recently attend radioprotection courses. The latter is related to increased awareness of techniques to reduce radiation exposure (96% vs. 81%, P = 0.022), registration of the delivered dose in each procedure (92% vs. 67%, P = 0.009), and X-ray equipment optimization (50% vs. 36%, P = 0.006). CONCLUSION: Italian interventional cardiologists show an acceptable level of radiation awareness and knowledge of updated European directives. However, there is clear space for improvement. Comparison to other health professionals, both at national and international levels, is needed to pursue proper X-ray management and protect public health.

Zero-fluoroscopy approach for ablation of supraventricular tachycardia using the Ensite NavX system: a multicenter experience.

BACKGROUND: Three-dimensional electroanatomic mapping systems have demonstrated a significant reduction in radiation exposure during radiofrequency catheter ablation procedures. We aimed to investigate the safety, feasibility and efficacy of a completely zero-fluoroscopy approach for catheter ablation of supraventricular tachycardia using the Ensite NavX navigation system compared with a conventional fluoroscopy approach. METHODS: A multicenter prospective non-randomized registry study was performed in seven centers from January 2013 to February 2018. Consecutive patients referred for catheter ablation of supraventricular tachycardia were assigned either to a completely zero-fluoroscopic approach (ZF) or conventional fluoroscopy approach (CF) according to the operator's preference. Patients with atrial tachycardia were excluded. RESULTS: Totally, 1020 patients were enrolled in ZF group; 2040 patients ablated by CF approach were selected for controls. There was no significant difference between the zero-fluoroscopy group and conventional fluoroscopy group as to procedure time (60.3 ± 20.3 vs. 59.7 ± 22.6 min, P = 0.90), immediate success rate of procedure (98.8% vs. 99.2%, P = 0.22), arrhythmia recurrence (0.4% vs. 0.5%, P = 0.85), total success rate of procedure (98.4% vs. 98.8%, P = 0.39) or complications (1.1% vs. 1.5%, P = 0.41). Compared with the conventional fluoroscopy approach, the zero-fluoroscopy approach provided similar outcomes without compromising the safety or efficacy of the procedure. CONCLUSION: The completely zero-fluoroscopy approach demonstrated safety and efficacy comparable to a conventional fluoroscopy approach for catheter ablation of supraventricular tachycardia, and mitigated radiation exposure to both patients and operators. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT03042078; first registered February 3, 2017; retrospectively registered.

Non-invasive Risk Stratification in Pediatric Ventricular Pre-excitation.

Children with ventricular pre-excitation are at risk for sudden death. This retrospective pediatric study identified patients > 8 years of age who had undergone electrophysiology study (EPS). Our primary objective was to determine the performance characteristics of non-invasive risk stratification. Subjects were separated into two groups. Group 1 was asymptomatic or had non-specific symptoms (palpitations, chest pain, and light headedness) without documented supraventricular tachycardia (SVT). Group 2 had syncope, documented SVT, or a life-threatening event. As a secondary aim, we tested whether patients with severe symptoms had a shorter time from the date of diagnosis to the date of invasive risk stratification. Among 93 patients with an average age of 14.2 years, 25 patients had documented SVT, 6 had syncope, and 1 had a life-threatening event. The sensitivity of non-invasive risk stratification was 7%. The specificity was 91%. The positive predictive valve was 14% and the negative predictive value was 84%. Even patients with severe symptoms commonly underwent non-invasive risk stratification prior to EPS, albeit at a lower rate (Group 1, 98%; Group 2 84%, p = 0.02). The median time to EPS was 4.2 months (Group 1) and 4.5 months (Group 2, p = 0.63). Non-invasive risk stratification was a poor predictor of invasive risk stratification. Cardiologists should counsel families about the limitations of non-invasive risk stratification and consider starting with invasive risk stratification and possible ablation. Counterintuitively, severe symptoms were not associated with a shorter time to electrophysiology study.

[La rilevazione e il trattamento del dolore durante le procedure di emodinamica e elettrofisiologia: uno studio descrittivo multicentrico]. / Measurement and management of pain during coronary interventions and electrophysiology procedures: a multicentric descriptive study.

INTRODUCTION: Coronary interventions and electrophysiology procedures may be painful both during and shortly after the procedure. AIM: To assess the onset of pain and anxiety in patient undergoing coronary interventions and electrophysiology procedures; to describe the administration (frequency, timing, dosage and outcomes) of analgesics and anxiolytics before, during and after the procedure. METHODS: A descriptive multicenter study was carried out. Pain and anxiety were measured with a 10-point visual analogue scale (VAS) before, during, after the procedure and for the following 24 hours. Patient were asked to rate their satisfaction for the information received and pain control. RESULTS: Data on 230 patients were collected. The most performed procedure was the transradial coronary catheterization (68.7%). The pacemaker/defibrillator implantation resulted the most painful procedure (median 4, IQR 3-6) and also the most anxious (median 5, IQR 2-6). 13 Patients received an analgesic during the procedure for a low-to-severe pain; during the following 24 hours 34 patients (5 undergoing transradial coronary catheterization and 29 the implant of pacemaker/cardiac-defibrillator) suffered from severe pain and with the exception of 5, all requested pain relief. Satisfaction for pain control was inadequate for patients who underwent electrophysiology procedures and 55 patients would have needed more information on pain. CONCLUSION: Pain control and patient satisfaction may be improved, pre-procedural anxiety needs more attention and better information on the procedure should be provided.

Pain During "Noncomplex" Electrophysiological Studies and Cardiac Rhythm Device Surgery.

BACKGROUND: There are only limited data about peri-interventional pain during cardiac electrophysiological procedures without analgosedation. In this study, peri-interventional pain and recollection of it after the intervention were evaluated. METHODS: A total of 101 patients (43 electrophysiological/ablation procedures and 58 device surgeries) reported pain on a numerical rating scale (NRS; 0-10) before (pre), during (peri), and after (post) the intervention. Maximum pain (maxNRS) and the average of pain (meanNRS) were used for statistical analysis. Peri-interventional pain was compared with postinterventional data of the recollection of peri-interventional pain (peri-post). Patients were allocated into 2 groups (with 51 and 50 patients, respectively) to evaluate the mode of patient-staff interaction on pain recollection. Depressive, anxiety, and somatic symptom scales (Patient Health Questionnaire-15, Generalized Anxiety Disorder-7, and Patient Health Questionnaire-15) were used to analyze their influence on pain recollection. RESULTS: In total, 49.6% of patients (n = 50) complained of moderate to severe pain (maxNRS) at least once during the procedure. The comparison between peri and peri-post data revealed the following (median (range)-maxNRS, peri: 3 (0-10) versus peri-post: 4 (0-9) (ns), and meanNRS, peri: 1.4 (0-7) versus peri-post: 2.0 (0-6) (ns). The mode of patient-staff interaction had no influence on pain. No effect was found for psychosocial factor concerning pain and the recollection of pain. The results of the linear regression showed no influence of low-dose midazolam on recollection of pain. CONCLUSION: Half of the patients reported moderate to severe pain at least once during cardiac electrophysiological procedures without analgosedation. However, on average, patients reported only low pain levels. Postinterventional derived data on discomfort reflect the peri-interventional situation.

From near-zero to zero fluoroscopy catheter ablation procedures.

AIMS: The use of electroanatomical mapping (EAM) systems can reduce radiation exposure (RX) and it can also completely eliminate the use of RX. Radiation exposure related to conventional radiofrequency ablation procedures can have a stochastic and deterministic effect on health. The main aim of this study was to evaluate the safety and feasibility of an entirely nonfluoroscopic approach to catheter ablation (CA) using EAM CARTO3. METHODS: In 2011 we started an RX-minimization programme in all procedures using the CARTO system with the deliberate intention to not resort to the aid of RX unless strictly necessary. We divided procedures into two groups (group 1: from 2011 to 2013; group 2: from 2014 to 2017). The only exclusion criteria were the need for transseptal puncture, and nonidiopathic ventricular tachycardia (VT). RESULTS: From a total of 525 procedures, we performed CA entirely without RX in 78.5% of cases. From 2011 to 2013, we performed CA without RX in 38.5% of cases; from 2014 to 2017, we performed 96.2% of cases with zero RX. The use of RX was significantly reduced in group 2 (group 2: 1.4 ± 19.6 seconds vs group 1: 556.92 ± 520.76 seconds; P < .001). These differences were irrespective of arrhythmia treatment. There were no differences between the two groups in acute success, complications, or duration of procedures. CONCLUSION: CA of supraventricular tachycardia and VT entirely without RX, guided by the CARTO system, is safe, feasible, and effective. After an adequate learning curve, CA can be performed entirely without RX.

Safety and compatibility of smart device heart rhythm monitoring in patients with cardiovascular implantable electronic devices.

INTRODUCTION: Emerging medical technology has allowed for monitoring of heart rhythm abnormalities using smartphone compatible devices. The safety and utility of such devices have not been established in patients with cardiac implantable electronic devices (CIEDs). We sought to assess the safety and compatibility of the Food and Drug Administration-approved AliveCor Kardia device in patients with CIEDs. METHODS AND RESULTS: We prospectively recruited patients with CIED for a Kardia recording during their routine device interrogation. A recording was obtained in paced and nonpaced states. Adverse clinical events were noted at the time of recording. Electrograms (EGMs) from the cardiac device were obtained at the time of recording to assess for any electromagnetic interference (EMI) introduced by Kardia. Recordings were analyzed for quality and given a score of 3 (interpretable rhythm, no noise), 2 (interpretable rhythm, significant noise) or 1 (uninterpretable). A total of 251 patients were recruited (59% with a pacemaker and 41% with ICD). There were no adverse clinical events noted at the time of recording and no changes to CIED settings. Review of all EGMs revealed no EMI introduced by Kardia. Recordings were correctly interpreted in 90% of paced recordings (183 had a score of 3, 43 of 2, and 25 of 1) and 94.7% of nonpaced recordings (147 of 3, 15 of 2, and 9 of 1). CONCLUSION: The AliveCor Kardia device has an excellent safety profile when used in conjunction with most CIEDs. The quality of recordings was preserved in this population. The device, therefore, can be considered for heart rhythm monitoring in patients with CIEDs.

Management of acute cardiac tamponade by direct autologous blood transfusion in interventional electrophysiology.

AIMS: Acute cardiac tamponade (ACT) is the most common life-threatening complication of interventional electrophysiology. Urgent drainage by percutaneous pericardiocentesis and anticoagulation reversal are required. Immediate direct transfusion of the blood volume aspirated from the pericardial space to the patient has been rarely described. This study was designed to assess the efficacy and safety of immediate direct autologous blood transfusion (AutoBT). METHODS: A retrospective case series of direct AutoBT performed for ACT was collected. Urgent drainage by percutaneous pericardiocentesis and immediate direct AutoBT were performed to achieve hemodynamic stabilization without a cell-saver system. RESULTS: Twenty-two electrophysiology centers were contacted to participate in the case series. Fourteen centers reported not to use direct AutoBT. Three centers reported using direct AutoBT with the cell-saver system. Fourteen cases of immediate direct AutoBT without cell-saver system were included from the five remaining centers. Electrophysiological procedures were performed for ventricular tachycardia (n = 5), atrial fibrillation (n = 5), atrial tachycardia (n = 2), left accessory pathway (n = 1), and premature ventricular contraction (n = 1) with transseptal (n = 9), retroaortic (n = 4), and/or epicardial access (n = 4). Pericardial drainage was performed by percutaneous pericardiocentesis for 13 patients and via the transseptal sheath for one patient. Surgical hemostasis was required for seven patients. The mean volume of autologous blood directly transfused was 1207 ± 963 mL. Direct AutoBT permitted to resume the procedure in four patients. No major complication related to the use of AutoBT occurred. CONCLUSION: Direct AutoBT without a cell-saver system is a feasible, safe, and useful technique for salvage therapy in ACT in interventional electrophysiology.

Cardiac electrophysiologic procedures - A ten years' experience at National Institute of Cardiovascular Diseases, Karachi.

OBJECTIVE: To review 10 years of clinical practice of cardiac electrophysiology study and radiofrequency catheter ablation in the treatment of supraventricular tachycardia. METHODS: The retrospective chart review was conducted at the National Institute of Cardiovascular Diseases, Karachi, and comprised records of all patients who underwent electrophysiological study and / or radiofrequency catheter ablation from January2007 to December 2016. SPSS 21 was used for data analysis. RESULTS: Of the 627 patients, 335(53.4%) were females. The overall mean age was 40.99}13.59 years. The major indication for procedure was supraventricular tachycardia 376(59.97%). Final electrophysiological study diagnosis was typical slow fast atrioventricular nodal re-entrant tachycardia in 303(48.3%) patients. The overall success rate was 472(75.3%). Procedure-related complications were reported in 25(4%) patients, and there was 1(0.15%) mortality. CONCLUSIONS: Cardiac electrophysiology studies and radiofrequency catheter ablation were found to be an effective and safe method for diagnosis and treatment of supraventricular tachycardia.

Real-world comparison of in-hospital Reveal LINQ insertable cardiac monitor insertion inside and outside of the cardiac catheterization or electrophysiology laboratory.

BACKGROUND: Traditionally, insertable cardiac monitor (ICM) procedures have been performed in the cardiac catheterization (CATH) or electrophysiology (EP) laboratory. The introduction of the miniaturized Reveal LINQ ICM has led to simplified and less invasive procedures, affording hospitals flexibility in planning where these procedures occur without compromising patient safety or outcomes. METHODS: The present analysis of the ongoing, prospective, observational, multicenter Reveal LINQ Registry sought to provide real-world feasibility and safety data regarding the ICM procedure performed in the CATH/EP lab or operating room and to compare it with insertions performed outside of these traditional hospital settings. Patients included had at least a 30-day period after the procedure to account for any adverse events. RESULTS: We analyzed 1222 patients (58.1% male, age 61.0 ± 17.1 years) enrolled at 18 centers in the US, 17 centers in Middle East/Asia, and 15 centers in Europe. Patients were categorized into 2 cohorts according to the location of the procedure: in-lab (CATH lab, EP lab, or operating room) (n = 820, 67.1%) and out-of-lab (n = 402, 32.9%). Several differences were observed regarding baseline and procedure characteristics. However, no significant differences in the occurrence of procedure-related adverse events (AEs) were found; of 19 ICM/procedure-related AEs reported in 17 patients (1.4%), 11 occurred in the in-lab group (1.3%) and 6 in the out-of-lab group (1.5%) (P = .80). CONCLUSIONS: This real-world analysis demonstrates the feasibility of performing Reveal LINQ ICM insertion procedures outside of the traditional hospital settings without increasing the risk of infection or other adverse events.

Rate of acquired pulmonary vein stenosis after ablation of atrial fibrillation referred to electroanatomical mapping systems: Does it matter?

BACKGROUND: Thermal injury during radiofrequency ablation (RFA) of atrial fibrillation (AF) can lead to pulmonary vein stenosis (PVS). It is currently unclear if routine screening for PVS by imaging (echocardiography, computed tomography) is clinically meaningful and if there is a correlation between PVS and the electroanatomical mapping system (EAMS) used for the ablation procedure. It was therefore investigated in the current single center experience. METHODS: All patients from January 2004 to December 2016 with the diagnosis of PVS after interventional ablation of AF by radiofrequency were retrospectively analyzed. From 2004 to 2007, transesophageal echocardiography was routinely performed as screening for RFA-acquired PVS (group A). Since 2008, diagnostics were only initiated in cases of clinical symptoms suggestive for PVS (group B). RESULTS: The overall PVS rate after interventional RFA for AF of the documented institution is 0.72% (70/9754). The incidence was not influenced by screening: group A had a 0.74% PVS rate and group B a 0.72% rate (NS). Referred to as the EAMS, there were significant differences: 20/4229 (0.5%) using CARTO®, 48/4510 (1.1%) using EnSite®, 1/853 (0.1%) using MediGuide®, and 1/162 (0.6%) using Rhythmia®. Since 2009, no significant difference between technologies was found. CONCLUSIONS: The present analysis of 9754 procedures revealed 70 cases of PVS. The incidence of PVS is not related to screening but to the application of different EAMS. Possible explanations are technological backgrounds (magnetic vs. electrical), learning curves, operator experience, and work-flow differences. Furthermore, incorporation of new technologies seems to be associated with higher incidences of PVS before workflows are optimized.

Prevention of venous thrombosis after electrophysiology procedures: a survey of national practice.

PURPOSE: Femoral venous access is required for most electrophysiology procedures. Limited data are available regarding post-procedure venous thromboembolism (VTE), specifically deep vein thrombosis (DVT) and pulmonary embolism (PE). Potential preventative strategies are unclear. We aimed to survey Canadian centers regarding incidence of VTE and strategies for prevention of VTE after procedures that do not require post-procedure anticoagulation. METHODS: An online survey was distributed to electrophysiologists representing major Canadian EP centers. Participants responded regarding procedural volume, incidence of VTE post-procedure, and their practice regarding pharmacological and non-pharmacological peri-procedural VTE prophylaxis. RESULTS: The survey included 17 centers that performed a total of 6062 procedures in 2016. Ten patients (0.16%) had VTE (including 9 DVTs and 6 PEs) after diagnostic electrophysiology studies and right-sided ablation procedures excluding atrial flutter. Five centers (41.6%) administered systemic intravenous heparin during both diagnostic electrophysiology studies and right-sided ablation procedures. For patients taking oral anticoagulants, 10 centers (58.8%) suspend therapy prior to the procedure. Two centers (11.8%) routinely prescribed post-procedure pharmacologic prophylaxis for VTE. Four centers (23.5%) used compression dressings post-procedure and all prescribed bed rest for a maximum of 6 h. Of the variables collected in the survey, none were found to be predictive of VTE. CONCLUSIONS: VTE is not a common complication of EP procedures. There is significant variability in the strategies used to prevent VTE events. Future research is required to evaluate strategies to reduce the risk of VTE that may be incorporated into EP practice guidelines.

X-Ray Exposure in Cardiac Electrophysiology: A Retrospective Analysis in 8150 Patients Over 7 Years of Activity in a Modern, Large-Volume Laboratory.

BACKGROUND: Only a few studies have systematically evaluated fluoroscopy data of electrophysiological and device implantation procedures. Aims of this study were to quantify ionizing radiation exposure for electrophysiological/device implantation procedures in a large series of patients and to analyze the x-ray exposure trend over years and radiation exposure in patients undergoing atrial fibrillation ablation considering different technical aspects. METHODS AND RESULTS: We performed a retrospective analysis of all electrophysiological/device implantation procedures performed during the past 7 years in a modern, large-volume laboratory. We reported complete fluoroscopy data on 8150 electrophysiological/device implantation procedures (6095 electrophysiological and 2055 device implantation procedures); for each type of procedure, effective dose and lifetime attributable risk of cancer incidence and mortality were calculated. Over the 7-year period, we observed a significant trend reduction in fluoroscopy time, dose area product, and effective dose for all electrophysiological procedures (P<0.001) and a not statistically significant trend reduction for device implantation procedures. Analyzing 2416 atrial fibrillation ablations, we observed a significant variability of fluoroscopy time, dose area product and effective dose among 7 different experienced operators (P<0.0001) and a significant reduction of fluoroscopy use over time (P<0.0001) for all of them. Considering atrial fibrillation ablation techniques, fluoroscopy time was not different (P = 0.74) for radiofrequency catheter ablation in comparison with cryoablation, though cryoablation was still associated with higher dose area product and effective dose values (P<0.001). CONCLUSIONS: Electrophysiological procedures involve a nonnegligible x-ray use, leading to an increased risk of malignancy. Awareness of radiation-related risk, together with technological advances, can successfully optimize fluoroscopy use.

Therapy Of Cardiac Arrhythmias In Children: An Emerging Role Of Electroanatomical Mapping Systems.

INTRODUCTION: Cardiac arrhythmias are challenging diseases in childhood. Most of them in pediatric subjects (90.2%) are atrioventricular reentrant tachycardias and atrioventricular nodal reentrant tachycardias. The standard 12-lead ECG is a highly accurate diagnostic tool but an invasive electrophysiological study is often required. The main concern about this kind of procedures is their invasive nature and the need of radiations, so antiarrhythmic agents are currently the first line therapy. However, they often show side effects and can be insufficient for the rate control. MATERIALS AND METHODS: We performed a systematic research on Embase and PubMed. We found 563 articles and selected the most representative 50. DISCUSSION: Management of cardiac arrhythmias could be very difficult in several scenarios, especially in children with body weight <15 kg and age <4 years. In general, pediatric subjects show a cumulative risk of malignancy greater than adults, having greater life expectancy. On this basis the guiding principle during radiation delivery in electrophysiological procedures is "as low as reasonably achievable" (acronym: ALARA). The development of 3-dimensional (3D) electroanatomical mapping systems allowed significant reduction of exposure. The most recently reported experiences demonstrate safety and feasibility of fluoroless ablation in the most common arrhythmias in children, even in challenging conditions. CONCLUSION: The first reasonable approach in cardiac arrhythmias involving younger patients seems to be pharmacological. However antiarrhythmic drugs pose problems both in terms of side effects and often have poor efficacy. Expertise in electrophysiological techniques is constantly increasing and the development of new technologies allow us to encourage the use of electroanatomical mapping systems in order to reduce the radiation exposure in children undergoing to catheter ablation, especially for accessory pathways.

Reducing radiation exposure during procedures performed in the electrophysiology laboratory.

INTRODUCTION: Expert societies recently published strong recommendations to reduce the exposure of patients and staff to ionizing radiation (IR) during interventional and electrophysiology (EP) procedures. However, adherence to these guidelines remains difficult and the impact of implementing such recommendations is poorly characterized. METHODS AND RESULTS: We conducted a single-center cohort study to quantify radiation exposure over time in three EP laboratories at the Montreal Heart Institute during 5,546 consecutive procedures from 2012 to 2015 by 11 primary operators. Overall, 2,618 (47.2%) procedures were catheter-based and 2,928 (52.8%) were device interventions. Interventions to reduce radiation exposure included educational initiatives to raise awareness (i.e., limiting cine acquisition, patient position, table height), slower frame rate, lower radiation dose per pulse, collimation, and integration with 3-D mapping systems and/or MediGuide technology. An 85% reduction in IR exposure was observed from 2012 to 2015, with the mean dose-area-product (DAP) decreasing from 7.65 ± 0.05 Gy·cm2 to 1.15 ± 0.04 Gy·cm2 (P < 0.001). This was true for catheter-based procedures (mean DAP 16.99 ± 0.08 to 2.00 ± 0.06 Gy·cm2 , P < 0.001) and device interventions (mean DAP 4.18 ± 0.06 to 0.64 ± 0.05 Gy·cm2 , P < 0.001). The median effective dose of IR recorded per quarter by 282 cervical dosimeters on EP staff decreased from 0.57 (IQR 0.18, 1.03) mSv in 2012 to 0.00 (IQR 0.00, 0.19) mSv in 2015, P < 0.001. CONCLUSION: Enforcing good clinical practices with simple measures and low-dose fluoroscopy settings are highly effective in reducing IR exposure in the EP lab. These promising results should encourage other EP labs to adopt similar protective measures.