Combining conventional technique with fluoroscopy integration module in accessory pathway ablation

INTRODUCTION

Accessory pathway (AP) ablation is a straightforward approach with high success rates, but the fluoroscopy time (FT) is significantly longer in conventional technique. Electroanatomical mapping systems (EMS), reduce the FT, but anatomical and activation mapping may prolong the procedure time (PT). The fluoroscopy integration module (FIM) uses prerecorded fluoroscopy images and allows ablation similar to conventional technique without creating an anatomical map. In this study, we investigated the effects of combining the FIM with traditional technique on PT, success, and radiation exposure.

METHODS

A total of 131 patients who had undergone AP ablation were included in our study. In 37 patients, right and left anterior oblique (RAO-LAO) images were acquired after catheter placement and integrated with the FIM. The ablation procedure was then similar to the conventional technique, but without the use of fluoroscopy. For the purpose of acceleration, anatomical and activation maps have not been created. Contact-force catheters were not used. 94 patients underwent conventional ablation using fluoroscopy only.

RESULTS

FIM into AP ablation procedures led to a significant reduction in radiation exposure, lowering FT from 7.4 to 2.8 min (p < .001) and dose-area product from 12.47 to 5.8 μGym² (p < .001). While the FIM group experienced a reasonable longer PT (69 vs. 50 min p < .001). FIM reduces FT regardless of operator experience and location of APs CONCLUSION: Combining FIM integration with conventional AP ablation offers reduced radiation exposure without compromising success rates and complication.

Practical guidance to reduce radiation exposure in electrophysiology applying ultra low-dose protocols: a European Heart Rhythm Association review

Interventional electrophysiology offers a great variety of treatment options to patients suffering from symptomatic cardiac arrhythmia. Catheter ablation of supraventricular and ventricular tachycardia has globally evolved a cornerstone in modern arrhythmia management. Complex interventional electrophysiological procedures engaging multiple ablation tools have been developed over the past decades. Fluoroscopy enabled interventional electrophysiologist throughout the years to gain profound knowledge on intracardiac anatomy and catheter movement inside the cardiac cavities and hence develop specific ablation approaches. However, the application of X-ray technologies imposes serious health risks to patients and operators. To reduce the use of fluoroscopy during interventional electrophysiological procedures to the possibly lowest degree and to establish an optimal protection of patients and operators in cases of fluoroscopy is the main goal of modern radiation management. The present manuscript gives an overview of possible strategies of fluoroscopy reduction and specific radiation protection strategies.

Utility of cardiac imaging in patients with ventricular tachycardia

Ventricular tachycardia (VT) is a life-threatening arrhythmia that may be idiopathic or result from structural heart disease. Cardiac imaging is critical in the diagnostic workup and risk stratification of patients with VT. Data gained from cardiac imaging provides information on likely mechanisms and sites of origin, as well as risk of intervention. Pre-procedural imaging can be used to plan access route(s) and identify patients where post-procedural intensive care may be required. Integration of cardiac imaging into electroanatomical mapping systems during catheter ablation procedures can facilitate the optimal approach, reduce radiation dose, and may improve clinical outcomes. Intraprocedural imaging helps guide catheter position, target substrate, and identify complications early. This review summarises the contemporary imaging modalities used in patients with VT, and their uses both pre-procedurally and intra-procedurally.

Adding interactive face-to-face lectures to passive lectures effectively reduces radiation exposure during atrial fibrillation ablation

BACKGROUND

Radiation exposure remains a major concern for electrophysiologists and patients. This study aimed to investigate the effect of altering awareness of radiation exposure during atrial fibrillation ablation using interactive face-to-face (FTF) lectures compared to passive lectures.

METHODS

Patients who underwent their first catheter ablation with radiofrequency energy for atrial fibrillation between January 2014 and December 2020 were included in this study. All operators attended an e-learning lecture on radiation exposure before catheter ablation. The addition of FTF lectures to this lecture was introduced in 2018. The effect on radiation exposure was compared between the pre-FTF and FTF periods by comparing fluoroscopy time and radiation dose.

RESULTS

A total of 896 patients [mean age, 66 ± 11 years; 603 men (67 %)] were included in this study. For pre-FTF (n = 345), only pulmonary vein isolation (PVI) was performed in 112 patients and PVI with additional ablation in 233 patients. For FTF lectures (n = 551), PVI-only was performed in 302 patients and PVI with additional ablation in 249 patients. Fluoroscopy time, cumulative air kerma, and cumulative air kerma per time significantly reduced after FTF introduction in both PVI-only group [pre-FTF and FTF; 37 ± 15 min and 16 ± 10 min (p < 0.0001), 477 ± 582 mGy and 108 ± 156 mGy (p < 0.0001), 11 ± 12 mGy/min, and 5 ± 6 mGy/min (p < 0.0001), respectively] and PVI with additional ablation group [pre-FTF and FTF; 48 ± 17 min and 15 ± 13 min (p < 0.0001), 613 ± 483 mGy and 68 ± 96 mGy (p < 0.0001), 12 ± 10 mGy/min, and 4 ± 4 mGy/min (p < 0.0001), respectively]. There were no significant differences in intraoperative complications between the two periods.

CONCLUSIONS

FTF lectures can reduce radiation exposure.

A novel image integration technology mapping system significantly reduces radiation exposure during ablation for a wide spectrum of tachyarrhythmias in children

Objective

Radiofrequency catheter ablation (RFCA) has evolved into an effective and safe technique for the treatment of tachyarrhythmia in children. Concerns about children and involved medical staff being exposed to radiation during the procedure should not be ignored. "Fluoroscopy integrated 3D mapping", a new 3D non-fluoroscopic navigation system software (CARTO Univu Module) could reduce fluoroscopy during the procedure. However, there are few studies about the use of this new technology on children. In the present study, we analyzed the impact of the CARTO Univu on procedural safety and fluoroscopy in a wide spectrum of tachyarrhythmias as compared with CARTO3 alone.

Methods

The data of children with tachyarrhythmias who underwent RFCA from June 2018 to December 2021 were collected. The CARTO Univu was used for mapping and ablation in 200 cases (C3U group) [boys/girls (105/95), mean age (6.8 ± 3.7 years), mean body weight (29.4 ± 7.9 kg)], and the CARTO3 was used in 200 cases as the control group (C3 group) [male/female (103/97), mean age (7.2 ± 3.9 years), mean body weight (32.3 ± 19.0 kg)]. The arrhythmias were atrioventricular reentrant tachycardia (AVRT, n = 78), atrioventricular node reentrant tachycardia (AVNRT, n = 35), typical atrial flutter (AFL, n = 12), atrial tachycardia (AT, n = 20) and ventricular arrhythmias [VAs, premature ventricular complexes or ventricular tachycardia, n = 55].

Results

① There was no significant difference in the acute success rate, recurrence rate, and complication rate between the C3 and C3U groups [(94.5% vs. 95.0%); (6.3% vs. 5.3%); and (2.0% vs. 1.5%); P > 0.05]. ② The CARTO Univu reduced radiation exposure: fluoroscopy time: AVRT C3: 8.5 ± 7.2 min vs. C3U: 4.5 ± 2.9 min, P < 0.05; AVNRT C3: 10.7 ± 3.2 min vs. C3U: 4.3 ± 2.6 min, P < 0.05; AT C3: 15.7 ± 8.2 min vs. C3U: 4.5 ± 1.7 min, P < 0.05; AFL C3: 8.7 ± 3.2 min vs. C3U: 3.7 ± 2.7 min, P < 0.05; VAs C3: 7.7 ± 4.2 min vs. C3U: 3.9 ± 2.3 min, P < 0.05. Corresponding to the fluoroscopy time, the fluoroscopy dose was also reduced significantly. ③ In the C3U group, the fluoroscopy during VAs ablation was lower than that of other arrhythmias (P < 0.05).

Conclusion

The usage of the "novel image integration technology" CARTO Univu might be safe and effective in RFCA for a wide spectrum of tachyarrhythmias in children, which could significantly reduce fluoroscopy and has a more prominent advantage for VAs ablation.

Temporal and geographical trends in women operators of electrophysiology procedures in the United States

BACKGROUND

Cardiac electrophysiology (EP) has few women physicians.

OBJECTIVE

The purpose of this study was to determine temporal and geographical trends in the proportion of women EP operators in the United States.

METHODS

We extracted data from the Medicare Provider Utilization and Payment Database from 2013 to 2019 using procedure codes for atrial fibrillation (AF) ablation, supraventricular tachycardia/atrial flutter (SVT/AFL) ablation, and cardiac device implantation. The Medicare Provider Utilization and Payment Database excludes operators who perform ≤10 procedures annually for a given individual procedure code. The proportion of women operators was compared across the 7-year period.

RESULTS

On average annually between 2013 and 2019, 5% (n = 187) of the 3524 EP operators were women. Procedure-specific analyses demonstrated a similarly low proportion of women EP operators across each procedure type. Despite a 137% increase in the total number of AF ablationists over the 7-year period, the proportion of women remained unchanged (P = .3966). The number of SVT/AFL ablationists and device operators remained constant over time as did the proportion of women operators (P = .9709 and .3583, respectively). In 2019, 10 states (20%) had no women EP operators who performed >10 of any given EP procedure annually, 20 states (39%) had no women who performed >10 of either AF or SVT/AFL ablation procedures annually, and 10 states (20%) had no women device operators who performed >10 of any given type of device implantation annually.

CONCLUSION

Women EP operators remain underrepresented, and the proportion of women is stagnant even in areas of major clinical growth such as AF ablation. One-fifth of states had no women operators who performed >10 of any given EP procedure annually.

Ablation index-guided cavotricuspid isthmus ablation with contiguous lesions using fluoroscopy integrated 3D mapping in atrial flutter

PURPOSE

The feasibility and safety of cavotricuspid isthmus (CTI) ablation with contiguous lesions using ablation index (AI) under the guidance of fluoroscopy integrated 3D mapping (CARTO UNIVU/CU) in typical atrial flutter (AFL) remains uncertain. This study aimed to determine the efficacy of AI-guided CTI ablation with contiguous lesions in patients with AFL.

METHODS

In this single-center, prospective, non-randomized, single-arm, observational study, procedural outcomes were determined in 151 patients undergoing AI-guided CTI ablation (AI group) with a target AI value of 450 and an interlesion distance of ≤ 4 mm under CU guidance. These outcomes were compared with those of 30 patients undergoing non-AI-guided ablation (non-AI group).

RESULTS

Among 151 patients, first-pass conduction block was achieved in 120 (80%) patients in the AI group (67% in the non-AI group, P = 0.152) with a shorter fluoroscopy time of 0.2 ± 0.4 min (1.7 ± 2.0 min in the non-AI group, P < 0.001). Conduction gaps were located at the atrial aspects near the inferior vena cava in 24 of 31 (78%) patients without first-pass conduction block. The AI group received 11 ± 5 (12 ± 4 in the non-AI group, P = 0.098) radiofrequency (RF) applications, and the RF time was 4.2 ± 2.4 (5.1 ± 2.5 min in the non-AI group, P = 0.011). Despite the occurrence of steam pop in 3 (2%) patients, none of them developed cardiac tamponade. No patients had recurrence within 6 months of follow-up.

CONCLUSIONS

AI-guided CTI ablation in combination with CU was feasible and effective in reducing radiation exposure in patients with AFL.

Zero-fluoroscopy ablation in patients with cardiac electronic implantable devices

INTRODUCTION

Utilizing a three-dimensional (3-D) mapping system and intracardiac echocardiography (ICE) has allowed ablation procedures with less or without fluoroscopy; however, there is limited data for patients with cardiac electronic implantable device (CIED) leads regarding the suspected risk of lead injury. Therefore, we sought to explore technics to perform safe trans-septal approach and catheter manipulation technique in patients with CIED leads.

METHODS AND RESULTS

This study comprised 49 consecutive patients (59% males, median 73 years old) with CIED who underwent catheter ablation for supraventricular tachycardia requiring the trans-septal approach, 15 without fluoroscopy (zero-fluoro group), and 34 with fluoroscopy (conventional-fluoro group), between July 2019 and April 2021. All procedures were performed under a 3-D mapping system and ICE guidance. We compared the differences in treatment and development of complications between the two groups. The procedures were for atrial fibrillation (82%) and atrial tachycardia (76%). Coronary sinus catheter insertion and the trans-septal procedure were successfully performed in all patients. The median time from venipuncture to trans-septal procedure (zero-fluoro vs. conventional-fluoro group: 28 [18-37] min vs. 24 [21-31] min, p = .70), total procedure time (231 [142-274] min vs. 175 [163-225] min, p = .63), and the acute procedural success rate (100% vs. 97%, p = 1.00) did not differ between both groups. No patient showed lead-related complications in both groups.

CONCLUSION

This is the first study to show zero-fluoro ablation for supraventricular arrhythmia using 3-D mapping and ICE in patients with CIED leads was feasible under careful catheter manipulation.

Image fusion of integrating fluoroscopy into 3D computed tomography in guidance of left atrial appendage closure

AIMS

We evaluated the feasibility of left atrial appendage (LAA) closure guided by the image fusion of integrating fluoroscopy into 3D computed tomography (CT).

METHODS AND RESULTS

A total of 117 consecutive patients who underwent LAA closure with or without the image fusion were matched (1:2). Each LAA closure step of the Image fusion group was guided by the preprocedure CT and image fusion, especially in the plan of LAA measurement and transseptal puncture. All patients were successfully implanted with a WATCHMAN closure device. Comparing the two groups, the mean number of recapture times and the number of devices per patient of the Image fusion group were significantly lower (0.4 ± 0.5 vs. 0.7 ± 0.8, P = 0.031 and 1.0 ± 0.2 vs. 1.1 ± 0.3, P = 0.027, respectively). The one-time successful deployment rate by the support of the image fusion was higher than in the control group (66.7% vs. 44.9%, P = 0.026). Each case of the Image fusion group was completely occluded with one transseptal puncture, while five of the Non-image fusion group required redo transseptal punctures. During the 45-day follow-up, both group cases presented occlusion efficiency and no major adverse cardiac events were observed.

CONCLUSION

Image fusion technique integrating fluoroscopy into the 3D CT is safe and feasible which can be easily incorporated into the procedural work-flow of percutaneous LAA closure. The fusion image can play an important alternative role in the plan of LAA measurement and transseptal puncture site for improving the LAA closure procedure.

Results from a real-time dosimetry study during left atrial ablations performed with ultra-low dose radiation settings

Background

Three-dimensional mapping systems and the use of ultra-low dose radiation protocols have supported minimization of radiation dose during left atrial ablation procedures. By using optimal shielding, scattered radiation reaching the operator can be further reduced. This prospective study was designed to determine the remaining operator radiation exposure during left atrial catheter ablations using real-time dosimetry.

Methods

Radiation dose was recorded using real-time digital dosimetry badges outside the lead apron during 201 consecutive left atrial fibrillation ablation procedures. All procedures were performed using the same X‑ray system (Siemens Healthineers Artis dBc; Siemens Healthcare AG, Erlangen, Germany) programmed with ultra-low dose radiation settings including a low frame rate (two frames per second), maximum copper filtration, and an optimized detector dose. To reduce scattered radiation to the operators, table-suspended lead curtains, ceiling-suspended leaded plastic shields, and radiation-absorbing shields on the patient were positioned in an overlapping configuration.

Results

The 201 procedures included 139 (69%) pulmonary vein isolations (PVI) (20 cryoballoon ablations, 119 radiofrequency ablations, with 35 cases receiving additional ablation of the cavotricuspid isthmus) and 62 (31%) PVI plus further left atrial substrate ablation.

Mean radiation dose measured as dose area product for all procedures was 128.09 ± 187.87 cGy ∙ cm² with a mean fluoroscopy duration of 9.4 ± 8.7 min. Real-time dosimetry showed very low average operator doses of 0.52 ± 0.10 µSv. A subanalysis of 51 (25%) procedures showed that the radiation burden for the operator was highest during pulmonary vein angiography.

Conclusion

The use of ultra-low dose radiation protocols in combination with optimized shielding results in extremely low scattered radiation reaching the operator.

Application of cardiac computed tomographic imaging and fluoroscopy fusion for guiding left atrial appendage occlusion

OBJECTIVE

Evaluate the value of 3D computed tomography (CT) and CT-integrating fluoroscopy for procedural guidance during WATCHMAN implantation.

METHODS

This observational study compared the clinical and procedural parameters for LAAO with and without fusion imaging. Forty-one pairs of patients-matched by procedure month and with or without the use of the image fusion system-were enrolled. Using the image fusion Advanced Workstation 4.6 software (GE Healthcare), we identified the 3D cardiac anatomy and safe zones for septal punch. The LAA orifice anatomy outlines were then projected onto the real-time fluoroscopy image during the procedure to guide all the steps of LAAO.

RESULTS

The use of image fusion significantly reduced the procedural time, compared to the time required for the control group (44.73 ± 20.03 min vs. 63.73 ± 26.10 min, respectively; P < 0.001). When compared to the standard procedure, the use of image fusion significantly reduced both the total radiation dose (448.80 ± 556.35 mGy vs. 798.42 ± 616.34 mGy; P = 0.004) and dose area product (DAP) (38.03 ± 47.15 Gy∙cm2 vs. 67.66 ± 52.23 Gy∙cm², P = 0.004). Corresponding to the radiation dose, the contrast volume was also reduced (67.32 ± 18.65 vs. 90.98 ± 25.03 ml; P = 0.0004). During short-term follow-up at 6 months, there was only one femoral hematoma and incomplete LAA sealing (>3 mm) in either group.

CONCLUSIONS

Automated real-time integration of cardiac CT and fluoroscopy is feasible, safe, and applicable in LAAO. It may significantly reduce the radiation exposure, procedure duration, and volume of contrast media. Following these results, the potential of merging reconstructed 3D CT scans with real-time coronary angiography should be fully exploited in LAAO.

Park Algorithm as Predictor of Premature Ventricular Contraction Origin in Three-Dimensional Mapping Electrophysiological Studies

PURPOSE

In the past few years, premature ventricular contraction (PVC) has attracted immense attention, both in patients with or without structural heart disease. Despite the technological advancement, no guiding tools are currently available to assist in the prediction of origin of PVC using a 12-lead electrocardiogram (ECG) before electrophysiology and ablation procedures. Park and co-workers compiled the existing algorithms for the morphology of ECG from the literature and generated a single algorithm based on specific features of ECG for the prediction of PVC origin. The Park algorithm is limited to idiopathic PVC and has not been evaluated clinically. In the present study, the Park algorithm was used to predict PVC origin in patients with or without structural heart disease and compared with the gold standard examination based on three-dimensional electrophysiological mapping studies.

PATIENTS AND METHODS

A cross-sectional study employing ECG data and electrophysiology study (EPS) reports from patients' medical records at Integrated Heart Center Wahidin Sudirohusodo Hospital, Makassar, Indonesia was conducted. The study was performed from April 2018 to June 2019 with a total of 31 samples; however, four samples were excluded during the EPS.

RESULTS

In the present study, the incidence of structural heart disease was 45.2%. The suitability of the Park algorithm for electrophysiological evaluation was 85.2%, both in the case of PVC with and/or without structural heart disease. The prediction of the origin of PVC in the right or left heart using the Park algorithm showed a sensitivity of 95%, specificity of 100%, positive predictive value of 100%, negative predictive value of 87.5%, and accuracy of 96%.

CONCLUSION

The findings of the study suggest significant accuracy of the Park algorithm in the prediction of location of origin of PVC. High sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the Park algorithm highlight its suitability to be used for determining the location of PVC origin in the right or left heart.

Predictors of zero X ray procedures in supraventricular arrhythmias ablation

To evaluate predictors of zero-X ray procedures for supraventricular arrhythmias (SVT) using minimally fluoroscopic approach (MFA). Patients referred for RF catheter ablation of SVT were admitted for a MFA with an electro-anatomical navigation system or a conventional fluoroscopic approach (ConvA). Exclusion criterion was the need to perform a transseptal puncture. 206 patients (98 men, age 53 ± 19 years) underwent an EP study, 93 (45%) with an MFA and 113 (55%) with a ConvA. Fifty-five had no inducible arrhythmias (EPS). Fifty-four had AV nodal reentrant tachycardia (AVNRT), 49 patients had typical atrial flutter (AFL), 37 had AV reciprocating tachycardia (AVRT/WPW), 11 had focal atrial tachycardia (AT), and underwent a RF ablation. X-ray was not used at all in 51/93 (58%) procedures (zero X ray). MFA was associated with a significant reduction in total fluoroscopy time (5.5 ± 10 vs 13 ± 18 min, P = 0.01) and operator radiation dose (0.8 ± 2.5 vs 3 ± 8.2 mSV, P < 0.05). The greatest absolute dose reduction was observed in AVNRT (0.1 ± 0.3 vs 5.1 ± 10 mSV, P = 0.01, 98% relative dose reduction) and in AFL (1.3 ± 3.6 vs 11 ± 16 mSV, P = 0.003, 88% relative dose reduction) groups. Both AVNRT or AFL resulted the only statistically significant predictors of zero x ray at multivariate analysis (OR 4.5, 95% CI 1.5-13 and OR 5, 95% CI 1.7-15, P < 0.001, respectively). Success and complication rate was comparable between groups (P = NS). Using MFA for SVT ablation, radiological exposure is significantly reduced. Type of arrhythmia is the strongest predictor of zero X ray procedure.

Meta-analysis of pulmonary vein isolation ablation for atrial fibrillation conventional vs low- and zero-fluoroscopy approaches

INTRODUCTION

Radiation exposure during catheter ablation procedures is a significant hazard for both patients and operators. Atrial fibrillation (AF) ablation procedures have been historically associated with higher fluoroscopy usage than other electrophysiology procedures. Recent efforts have been made to reduce dependence on fluoroscopy during pulmonary vein isolation (PVI) ablation procedures using alternative techniques.

METHODS

We performed a meta-analysis of studies comparing zero or low fluoroscopy (LF) vs conventional fluoroscopy (CF) approaches for AF ablation. Outcomes of interest included acute and 12-month procedural efficacy, safety, procedure duration, fluoroscopy time, and dose area product. Aggregated data were analyzed with random-effects models, using a Bayesian hierarchical approach.

RESULTS

A total of 2228 participants (LF, n = 1190 vs CF, n = 1038) from 15 studies were included in the meta-analysis. Risk of AF recurrence in 12 months (odds ratio [OR], 95% confidence interval [95% CI] = 1.343 [0.771-2.340]; P = .297), redo-ablation procedures (OR [95% CI] = 0.521 [0.198-1.323]; P = .186), and procedural complications (OR [95% CI] = 0.99 [0.485-2.204]; P = .979) were similar between LF- and CF-ablation groups. In comparison to CF ablation, LF ablation led to shorter procedure duration (weighted mean differences [WMDs] [95% CI] = -14.6 minutes [-22.5 to -6.8]; P < .001), fluoroscopy time (WMD [95% CI] = -8.8 minutes [-11.9 to -5.9]; P < .001), and dose area product (WMD [95% CI] = -1946 mGy/cm² [-2685 to 1207]; P < .001).

CONCLUSION

LF approaches have similar clinical efficacy and safety as CF approaches for PVI. LF approaches are associated with shorter procedure time, fluoroscopy usage, and dose area product during PVI.

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.

Safety and efficacy of zero fluoroscopy transseptal puncture with different approaches

INTRODUCTION

Atrial fibrillation (AF) ablation requires access to the left atrium (LA) via transseptal puncture (TP). TP is traditionally performed with fluoroscopic guidance. Use of intracardiac echocardiography (ICE) and three-dimensional mapping allows for zero fluoroscopy TP.

OBJECTIVE

To demonstrate safety and efficacy of zero fluoroscopy TP using multiple procedural approaches.

METHODS

Patients undergoing AF ablation between January 2015 and November 2017 at five institutions were included. ICE and three-dimensional mapping were used for sheath positioning and TP. Variable technical approaches were used across centers including placement of J wire in the superior vena cava with ICE guidance followed by dragging down the transseptal sheath into the interatrial septum, or guiding the transseptal sheath directly to the interatrial septum by localizing the ablation catheter with three-dimensional mapping and replacing it with the transseptal needle once in position. In patients with pacemaker/implantable cardiac defibrillator leads, pre-/poststudy device interrogation was performed.

RESULTS

A total of 747 TPs were performed (646 patients, age 63.1 ± 13.1, 67.5% male, LA volume index 34.5 ± 15.8 mL/m² , ejection fraction 57.7 ± 10.9%) with 100% success. No punctures required fluoroscopy. Two pericardial effusions, two pericardial tamponades requiring pericardiocentesis, and one transient ischemic attack were observed during the overall ablation procedure, with a total complication rate of 0.7%. There were no other periprocedural complications related to TP, including intrathoracic bleeding, stroke, or death both immediately following TP and within 30 days of the procedure. In patients with intracardiac devices, no device-related complications were observed.

CONCLUSION

TP can be safely and effectively performed without the need for fluoroscopy.

Three-dimensional image integration guidance for cryoballoon pulmonary vein isolation procedures

BACKGROUND

We present a new, easily applicable approach for the guidance of cryoballoon (CB) pulmonary vein isolation (PVI) procedures that use the combination of a 3D-mapping system image integration module and computed tomographic (CT)-derived anatomy. The aim of this retrospective, nonrandomized study was to investigate: (a) an alternative use for an established radiofrequency image integration module for cryo procedures; (b) a guidance technology for cryo PVI based on integrated CT anatomy; and (c) its clinical impact.

METHODS AND RESULTS

CT left atrium-angiography was performed in 50 consecutive patients before a CB PVI procedure, and a 3D reconstruction of the cardiac anatomy was segmented. A total of 25 patients were treated using conventional fluoroscopy; 25 patients were treated using the 3D image integration technique. In the image integration group, the CARTO3 UNIVU (Biosense Webster) module was used for image integration of 3D anatomy and fluoroscopic imaging. Transseptal puncture and cryo PVI were guided by 3D-overlay imaging. Procedures were feasible without complications in all patients and cryo PVI procedures were successfully guided using the image integration technique. The intraprocedural time needed to perform image integration was 37 ± 10 seconds. Fluoroscopy time was 31.7 ± 11.7 minutes in the conventional group and 20.1 ± 7.9 minutes in the image integration group (P < .001), procedure time was 116.3 ± 29.0 minutes in the conventional group vs 101.2 ± 20.9 minutes in the 3D group (P = .04).

CONCLUSION

3D-overlay guidance of CB PVI is feasible, safe, and applicable in real time with minimal effort. It may significantly reduce radiation exposure by introducing 3D information, known from electroanatomic mapping systems, into cryo PVI procedures.

Impact of Obesity on Overall Radiation Exposure for Patients Who Underwent Radiofrequency Ablation of Atrial Fibrillation

Patients who underwent radiofrequency ablation of atrial fibrillation are exposed to X-rays not only during the procedure but also during the preprocedural computed tomography. No study has investigated the cumulative effective dose received by patients who underwent atrial fibrillation ablation and identified factors influencing this dose. We aimed to evaluate the overall exposure to ionizing radiation in patients who underwent radiofrequency ablation of atrial fibrillation. The secondary objective was to estimate the impact of obesity on this exposure. All patients who underwent a first attempt of radiofrequency ablation of atrial fibrillation in our center over a 21 months period were included. Dosimetric indicators from preprocedural computed tomography and the ablation procedure were collected and converted into an effective dose. A total of 144 radiofrequency ablation of atrial fibrillation were included. The mean cumulative effective dose was 11.4 mSv, and 82% of the dose was from the computed tomography. Obese patients received a dose that was 75% higher than normal-weight patients, and this increase remained significant by multivariate analysis. In conclusion, overall exposure to ionizing radiation for patients who underwent radiofrequency ablation of atrial fibrillation seems acceptable, and the majority of the overall effective dose comes from the computed tomography. Obese patients are exposed to a 75% higher dose than normal-weight patients.

Reducing radiation exposure during atrial fibrillation ablation using lectures to promote awareness

Objective

Recently, concern has increased regarding the hazards of radiation exposure in patients and laboratory staff. Since the numbers of complex catheter ablations (CA) performed, duration of procedure times, and need for multiple sessions have increased, radiation exposure during each session needs to be minimised. Our study aimed to assess the impact of awareness on radiation exposure during CA for atrial fibrillation (AF).

Methods

Mini-course lectures was delivered to the physicians and staff in the electrophysiology division. Its effect on the fluoroscopic time and radiation dose during AF ablation before (Group I, n=70), shortly after (Group II: n=70) and remotely after the mini-lecture (Group III, n=70) were evaluated. Patient demographics, preoperative testing and procedural parameters were collected.

Results

The fluoroscopic time significantly reduced after the lecture (Group I and II: 25.1±10.0 and 15.1±7.3 min, respectively (p<0.0001)), and remained so in Group III (13.0±5.4 min), despite the increase in the number of persistent AFs. The radiation dose also significantly reduced (Groups I, II, III: 295.0±263.0, 109.6±103.5 and 110.1±89.6 mGy, respectively (p<0.0001)).

Conclusion

Awareness on radiation exposure led to a significant reduction in fluoroscopic time and radiation dose during CA for AF, the effect of which persisted even to remote periods following the procedure.

Feasibility of a novel mapping system combined with remote magnetic navigation for catheter ablation of premature ventricular contractions

BACKGROUND

Remote magnetic navigation (RMN) is often used in combination with a 3-dimensional mapping system to perform catheter ablations. This study aim to investigate the feasibility and effectiveness of a novel 3D-mapping system, EnSite Precision, combined with RMN for catheter ablation of premature ventricular contractions (PVCs), and compared it to the procedures performed by CARTO3 with RMN.

METHODS

Forty-three consecutive PVC patients were either ablated with the guidance of EnSite Precision (n = 22) or CARTO (n = 21) navigated by RMN. Procedure-related details, acute and long-term success were assessed.

RESULTS

Patient characteristics between both the groups were similar (age: 47.1 ± 19.8 vs 47.1 ± 12.7, female: 63.6% vs 57.1%). No significant difference was found in the procedure time (99.5 ± 30.4 vs 92.9 ± 24.8 min, P = 0.436), mapping time (18.6 ± 12.8 vs 15.5 ± 10.2 min, P = 0.390), radiofrequency ablation time (333.4 ± 267.0 vs 469.3 ± 343.1 s, P = 0.154), fluoroscopy time (4.0 ± 1.9 vs 3.8 ± 2.0 min, P = 0.635), and X-ray dose (1.8 ± 1.4 vs 2.0 ± 1.2 Gycm2, P = 0.649) between the two groups. No significant procedural complication occurred in either group. In addition, there was no significant differences regarding the acute success rate (90.9% vs 90.5%, P = 0.961) and long-term success rate (86.4% vs 81.0%, P = 0.631) after 16.2 ± 6.2 months of follow-up between the two groups.

CONCLUSIONS

RMN combined with EnSite Precision mapping system is effective and safe for catheter ablation of PVCs.

Reduction of atrial fibrillation burden by pulmonary vein isolation leads to a decrease of CD11b expression on inflammatory cells

Aims

It is hypothesized that inflammation could promote structural and electrical remodelling processes in atrial fibrillation (AF). Atrial infiltration of monocytes and granulocytes has been shown to be dependent on CD11b expression. The aim of this study was to investigate whether treatment of AF by pulmonary vein isolation (PVI) may lead to reduced inflammation, as indicated by a decrease of CD11b expression on monocytes and granulocytes.

Methods and results

Flow-cytometric quantification analysis and determination of systemic inflammatory markers of peripheral blood were performed in 75 patients undergoing PVI 1 day before and 6 months after PVI. The extent of activation of monocytes and granulocytes was measured by quantifying the cell adhesion molecule CD11b. The mean expression of CD11b on monocytes (20.9 ± 2.5 vs. 10.2 ± 1.4; P < 0.001) and granulocytes (13.9 ± 1.6 vs. 6.8 ± 0.5; P < 0.001), as well as the relative count of CD11b-positive monocytes (P < 0.05) and CD11b-positive granulocytes (P < 0.01) were significantly reduced when comparing the identical patients before and 6 months after PVI. Systemic inflammatory parameters showed only a declining tendency after 6 months. Patients with unsuccessful PVI and ongoing AF on the day of follow-up showed no decrease in CD11b expression.

Conclusions

A significant reduction of CD11b expression on monocytes and granulocytes, as a sign of reduced cellular inflammation, was achieved by treatment of AF using PVI. These data strongly support that AF is not only a consequence of but also a cause for inflammatory processes, which, in turn, may contribute to atrial remodelling.

Image integration into 3-dimensional-electro-anatomical mapping system facilitates safe ablation of ventricular arrhythmias originating from the aortic root and its vicinity

Aims

During ablation in the vicinity of the coronary arteries establishing a safe distance from the catheter tip to the relevant vessels is mandatory and usually assessed by fluoroscopy alone. The aim of the study was to investigate the feasibility of an image integration module (IIM) for continuous monitoring of the distance of the ablation catheter tip to the main coronary arteries during ablation of ventricular arrhythmias (VA) originating in the sinus of valsalva (SOV) and the left ventricular summit part of which can be reached via the great cardiac vein (GCV).

Methods and results

Of 129 patients undergoing mapping for outflow tract arrhythmias from June 2014 till October 2015, a total of 39 patients (52.4 ± 18.1 years, 17 female) had a source of origin in the SOV or the left ventricular summit. Radiofrequency (RF) ablation was performed when a distance of at least 5 mm could be demonstrated with IIM. A safe distance in at least one angiographic plane could be demonstrated in all patients with a source of origin in the SOV, whereas this was not possible in 50% of patients with earliest activation in the summit area. However, using the IIM a safe position at an adjacent site within the GCV could be obtained in three of these cases and successful RF ablation performed safely without any complications. Ablation was successful in 100% of patients with an origin in the SOV, whereas VAs originating from the left ventricular summit could be abolished completely in only 60% of cases.

Conclusion

Image integration combining electroanatomical mapping and fluoroscopy allows assessment of the safety of a potential ablation site by continuous real-time monitoring of the spatial relations of the catheter tip to the coronary vessels prior to RF application. It aids ablation in anatomically complex regions like the SOV or the ventricular summit providing biplane angiograms merged into the three-dimensional electroanatomical map.

Effect of Non-fluoroscopic Catheter Tracking on Radiation Exposure during Pulmonary Vein Isolation: Comparison of Four ablation systems

Background

A novel non-fluoroscopic catheter tracking system (Mediguide) can be used in combination with a 3D mapping system for atrial fibrillation (AF) ablation. However, the benefit on radiation exposure of the Mediguide system compared to other ablation systems is unknown.

Methods

We retrospectively enrolled consecutive 73 patients (51 men; 59±11 years; 60 paroxysmal AF) undergoing pulmonary vein isolation by the same operator. Radiation time, radiation effective dose, procedure time, AF recurrence after ablation, and procedure-related complications were compared among 4 different ablation systems.

Results

Mediguide was used in 16 patients (group A), CARTO™ in 17 (group B), Cryoballoon in 30 (group C), and Multi-electrode Pulmonary Vein Ablation Catheter (PVAC) in 10 (group D). Although procedure time was shorter in patients with Cryoballoon (median 110 [interquartile range 99-120] min) and PVAC (123 [112-146] min) compared to those with Mediguide (181 [168-214] min) and CARTO (179 [160-195] min) (P<0.001), radiation exposure time and effective dose were decreased in patients with Mediguide compared to the other ablation systems (A: 5 [3-6] min; B: 14 [11-16] min; C: 14 [11-18] min; D: 20 [16-24] min, P<0.001 and A: 1.1 [0.8-2.0] mSv; B: 2.5 [1.3-3.8] mSv; C: 2.0 [1.4-2.5] mSv; D: 1.7 [1.4-3.6] mSv, P=0.015, respectively). AF recurrence rates and procedure-related complications were comparable among the 4 groups.

Conclusion

The Mediguide system reduces radiation exposure compared to other ablation systems without increasing AF recurrence or procedure-related complications.

Development of simulation combining a physical heart model and three-dimensional system for electrophysiology training

BACKGROUND

A new three-dimensional heart anatomical simulator (3D HAS) has been created combining a physical heart model with an electroanatomic mapping (EAM) system. The aim of this study is to describe the development and the validation process of this device.

METHODS

We developed the 3D HAS combining a physical heart model with an EAM system. This simulator was then validated by 10 electrophysiologists, subdivided in two groups based on their experience in electrophysiology procedures. The performance of the experts was compared to the one of the novices in achieving three different tasks: fluoroless reconstruction of the right atrium, coronary sinus cannulation, and deployment of a linear ablation lesion in the cavotricuspid isthmus. For each operator, a score was calculated based on objective parameter for each task and for the overall performance.

RESULTS

The 3D HAS was located in an environment that allowed use of the main features of the EAM system including contact force sensing. No technical issue was encountered during the validation process. The experts' performance was significantly better than the one of the novices both overall (P = 0.009) and in each task (right atrium reconstruction, P = 0.016; coronary sinus cannulation, P = 0.008; ablation lesion, P = 0.03).

CONCLUSIONS

The 3D HAS is reliable and allows use of the main features of an EAM system in the right atrium. The ability to discriminate different levels of experience suggests that this simulator is enough realistic and could be useful for electrophysiology training.

Catheter ablation of atrial fibrillation with nonfluoroscopic catheter visualization-a prospective randomized comparison

PURPOSE

The application of a novel platform for nonfluoroscopic catheter sensor tracking within pre-recorded x-ray loops in the context of catheter ablation of atrial fibrillation (AF) demonstrated significant potential for reduction of fluoroscopy. We sought to provide the first prospective randomized comparison of fluoroscopy needs, procedure times, and complications in AF catheter ablation with or without additional use of nonfluoroscopic catheter visualization (NFCV).

METHODS

Patients with AF were randomized into two groups before scheduled radiofrequency ablation: (1) using established mapping systems and fluoroscopy as needed (CONV group) or (2) with additional NFCV (NFCV group). All procedures were performed in the same lab using the same ablation catheter tip technology and the same mapping and ablation strategies. Primary endpoints were radiation time and dose. Secondary endpoints were procedural parameters, complications, and long-term success.

RESULTS

A total of 80 patients (48 male patients, mean age 60 years, 46 patients with paroxysmal AF) were randomized into the two groups. Clinical parameters between both groups were similar. NFCV use reduced mean fluoroscopy time (1.9 vs. 13.2 min, p < 0.001) and mean dose (510 vs. 1549 Gycm², p < 0.001) significantly. Procedural parameters were similar in the two groups. One conservatively treated groin complication occurred (1.3%).

CONCLUSIONS

Radiation exposure can be significantly reduced by using the novel NFCV technology in addition to standard AF ablation technologies without negative effects on procedure durations, success rates, or complication rates. With the use of the technology, abandonment of lead protection for EP staff is possible following transseptal puncture.

Mapping of atrial fibrillation: strategies to understand an enigmatic arrhythmia

The three-dimensional (3D) mapping of cardiac arrhythmias has evolved in recent years to an important and extremely useful tool, providing important insights into arrhythmia mechanisms and thus improving ablation success rates, especially in complex arrhythmias. In atrial fibrillation (AF), the most common but also one of the most complex cardiac arrhythmias, progress in mapping technology has been focusing on several aspects according to the type of AF.In paroxysmal AF, important progress in the exact anatomic reconstruction of the main ablation target, i.e., the pulmonary veins (PV), has been achieved. Perhaps even more importantly, new insights into conduction patterns, such as deceleration at the PV ostia, spiral conduction more distally into the PV, and PV cross-talk have been detected and enable faster and more sustainable PV isolation.In persistent AF, the basic understanding of ongoing AF is perhaps the electrophysiological challenge of the 21st century. Since AF is instable in its course, mapping tools that assess statistically returning patterns or deal with so-called AF "rotors" or "drivers" have been developed, offering unique insights into possible AF mechanisms. Refined high-density bi-atrial voltage maps make it possible to further characterize the arrhythmogenic substrate and scar zones, while new and innovative mapping algorithms enable automated, fast, and reliable annotation of up to thousands of electrograms.This improved understanding of AF mechanisms has led to the development of promising new ablation strategies, some of which are already in use in clinical routine.

Fluoroscopy integrating technology in a 3D mapping system during ablation of atrial arrhythmias: first experiences

INTRODUCTION

Ablation of the cavotricuspid isthmus (CTI) in patients with atrial flutter (AFL) and pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF) are both common therapies. As the demand for ablative treatments rises, total radiation exposure times of staff increase concomitantly. Here, we report on our first experiences with a new fluoroscopy integrating system (FIS) integrated into a current 3D mapping system (3DMS).

MATERIAL AND METHODS

The study population consisted of 59 consecutive patients who underwent PVI or CTI ablation (26 and 33 patients with and without FIS respectively). Total procedure time (PT), fluoroscopy exposure time (FT) and dose-area product (DAP) were monitored.

RESULTS

All procedures were successfully completed without major complications. Employing FIS in the PVI group, FT and DAP were both significantly reduced after completing a short learning curve of 6 cases (respectively 361.6 ±181 s vs. 530.3 ±156.7 s, p = 0.039; 801.9 ±439.15 cGycm² vs. 1495 ±435.2 cGycm², p = 0.002). Mean PT was not significantly affected (121 ±26.7 min vs. 135.6 ±23.2 min, p = 0.21). The same holds true for CTI ablation: FT (99.29 ±51.4 s vs. 153.9 ±76.6 s, p = 0.022) and DAP (269 ±128.7 cGycm² vs. 524.3 ±288.4 cGycm², p = 0.002) were significantly reduced, leaving PT not significantly affected (29.5 ±10 min vs. 35.2 ±16.3 min, p = 0.23).

CONCLUSIONS

The introduction of the new FIS with a current 3DMS results in a significant reduction of both the total FT and DAP without affecting PT. The initial learning curve for adopting this method is considerably short.

3D Mapping for PVI- Geometry, Image Integration and Incorporation of Contact Force Into Work Flow

Catheter ablation of atrial fibrillation has evolved enormously thanks to rapid improvement of modern mapping technologies, progress in catheter development and current possibilities for reduction of radiation exposure. Pulmonary vein isolation is thereby the cornerstone in this interventional treatment. Increased precision of catheter localization by modern three-dimensional mapping systems, faster and better processing of local electrograms and their immediate color-based visualization make it possible to treat even challenging arrhythmias very effectively. The commonly used three-dimensional mapping systems CARTO 3 (Biosense Webster, Irvine, Ca.) and Ensite Precision (St. Jude Medical, St. Paul, Min) differ in construction and principles of the underlying mapping technology. In this review article, we aim to emphasize the most important aspects of possibilities that make both systems so valuable for interventional treatment of atrial fibrillation. We present a modern workflow, that unites three-dimensional LA mapping with collecting relevant local information, image integration for refining the map and beneficial use of contact force based ablation approach.

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.

Reconstruction left atrium and isolation pulmonary veins of paroxysmal atrial fibrillation using single contact force catheter with zero x-ray exposure: A CONSORT Study

BACKGROUND

Conventional ablation of paroxysmal atrial fibrillation (PAF) is associated with radiation risks for patients and laboratory staff. Three-dimensional (3D) mapping system capable of showing contact force (CF) and direction of catheter tip may compensate for nonfluoroscopic safety issues.

OBJECTIVE

The aim of this study was to investigate the feasibility of zero x-ray exposure during reconstruction left atrium (LA) and ablation.

METHODS

Single, CF catheter, and 3D mapping system were used to reconstruct LA and isolate pulmonary veins (PV) in all patients. The patients were randomly divided into 2 groups after LA angiography. In group 1, reconstruction LA and isolation PV was performed with the help of 3D system (without x-ray), whereas in group 2, x-ray and 3D system were utilized to reconstruct LA and ablate PV antrum. After ablation, Lasso catheter was used to confirm the PV isolation. All patients were followed up to 12 months.

RESULTS

A total of 342 PAF patients were continuously enrolled. The basic clinical characteristics between the 2 groups had no significant difference. Parameters related to the procedure, average procedure time, ablation procedure time, average contact force (CF) applied, the percentage of time within CF settings, and average power applied during radiofrequency application showed no significant difference between the 2 groups. In group 1, the average fluoroscopy time before LA reconstruction was similar to that in group 2 (2.8 ± 0.4 vs. 2.4 ± 0.6 minutes, P = .75). The average fluoroscopy time during ablation was significantly lower than that in group 2 (0 vs. 7.6 ± 1.3 minutes, P < .001). The total x-ray exposure dose of the procedure in group 1 was significantly lower than that in group 2 (19.6 ± 9.4 vs. 128.7 ± 62.5 mGy, respectively, P < .001). Kaplan-Meier analysis indicated that there were no statistical differences in the probability of freedom from atrial arrhythmia (AF/AFL/AT) recurrence at 12 months between group 1 and group 2 (P = .152). The success rate after a single ablation procedure and without drugs (Class I/III AAD) at 12 months was not significantly different between the 2 groups (67.6%, 95% confidence interval [CI]: 62%-79.5% in group 1 and 68.9%, 95% CI: 63%-80.7% in group 2, P = .207). Procedural-related adverse events showed no significant different incidence between group 1 and group 2. A multivariate logistic regression analysis of risk factors was performed to evaluate the effectiveness outcome, which demonstrated that the percentage of CF (within the investigator-selected work ranges) during therapy was significantly associated with positive outcomes (odds ratio: 3.68; 95% CI: 1.65-10.6, P = .008), whereas the LA dimension was negatively associated with effectiveness outcomes (odds ratio: 0.72; 95% CI: 0.52-0.84, P = .016).

CONCLUSIONS

Reconstruction LA and isolation PV ablation using single CF-assisted catheter without x-ray exposure was both safe and effective. CF was positively associated with effective outcomes and LA dimensions negatively with effective ones.

Pulmonary Vein Isolation for Atrial Fibrillation Can Be Achieved With Low Radiation Exposure

BACKGROUND

Atrial fibrillation is common and management by pharmacotherapy is limited by modest efficacy and significant toxicities. Pulmonary vein isolation (PVI) is a safe and effective alternative in select patients with atrial fibrillation. However, prolonged procedure time raises concerns of health risks from radiation exposure. This study aims to determine the significance of radiation exposure from PVI.

METHODS

In this study, we retrospectively reviewed patient demographics, fluoroscopy time, entrance skin dose and dose area product in 80 cases of PVI, radiofrequency ablation for atrial flutter and diagnostic coronary angiogram performed in our institution.

RESULTS

Compared to other procedures, patients who underwent PVI were younger (age, mean±standard error of mean, 59.4±1.1 years old, p<0.0001) and were more likely to be male (82%, p<0.001). Body mass index was similar between the three groups. The median (and interquartile range) fluoroscopy time was similar between PVI (20.8 and 13.1-30.7mins) and flutter ablation (17.6 and 11.1-26.1mins) but longer than diagnostic angiography (4.2 and 2.3-6.7mins, p<0.0001). Entrance skin dose was similar between PVI and flutter ablation groups but significantly higher in the diagnostic angiography group, with median and IQR for PVI vs. flutter ablation vs. diagnostic angiography, 100.4 (52.8-179.9) vs. 73.2 (37.0-142.1) vs. 393.5 (276.1-555.6) mGy (p<0.0001). Dose area product in PVI (1831.2 and 887.7-3460.8cGycm²) was higher than flutter ablation (1077.8 and 452.9-2410.2cGycm², p<0.05) but lower than the diagnostic angiography group (3446.8 and 2341.9-5283.1cGycm², p<0.0001). The fluoroscopy time and entrance skin dose for PVI decreased over time, likely due to increased operator experience.

CONCLUSIONS

Despite prolonged procedure time, radiation exposure from PVI was comparable to, or lower than, other fluoroscopy-guided cardiac procedures.

Radiofrequency catheter ablation of left-sided accessory pathways in children using a new fluoroscopy integrated 3D-mapping system

Introduction

Advances in 3D electroanatomic-mapping technologies have resulted in a safe and effective profile of radiofrequency (RF) catheter ablation. The aim of this study was to evaluate a different catheter ablation approach in patients with left-sided accessory pathways (APs).

Methods and results

From January 2015 to December 2015, 30 patients (median age 11 years, median weight 45 kg) with manifest or concealed left-sided APs underwent RF catheter ablation with a new protocol. All procedures were performed with the CARTO UNIVU™ system, integrating electroanatomic maps with fluoroscopic views. A 7 Fr ablation catheter was inserted into the right femoral vein and advanced into the right atrium. Geometrical reconstruction and activation map of the right atrium, tricuspid annulus, and coronary sinus were acquired. The ablation catheter was then inserted into the left femoral artery and advanced through the aorta and aortic valve, creating an activation map of the mitral annulus. Catheter ablation was targeted to the site of the earliest activation. No complications occurred. The median procedure and fluoroscopy times were 130 min and 6 s, with a median fluoroscopy dose 0.5 mGy. An average of two catheters was used. Long-term success rate was 97% (29/30) at a median follow-up of 9.6 months. This approach reduced fluoroscopy time, dose and number of catheters used compared with manifest or concealed left-sided AP ablation using CARTO 3™ (P < 0.05).

Conclusions

This new ablation protocol seems to be promising in reducing fluoroscopy exposure and number of catheters used during left-sided AP ablation in children.

Extremely low-frame-rate digital fluoroscopy in catheter ablation of atrial fibrillation: A comparison of 2 versus 4 frame rate

Despite the technological advance in 3-dimensional (3D) mapping, radiation exposure during catheter ablation of atrial fibrillation (AF) continues to be a major concern in both patients and physicians. Previous studies reported substantial radiation exposure (7369-8690 cGy cm) during AF catheter ablation with fluoroscopic settings of 7.5 frames per second (FPS) under 3D mapping system guidance. We evaluated the efficacy and safety of a low-frame-rate fluoroscopy protocol for catheter ablation for AF.Retrospective analysis of data on 133 patients who underwent AF catheter ablation with 3-D electro-anatomic mapping at our institute from January 2014 to May 2015 was performed. Since January 2014, fluoroscopy frame rate of 4-FPS was implemented at our institute, which was further decreased to 2-FPS in September 2014. We compared the radiation exposure quantified as dose area product (DAP) and effective dose (ED) between the 4-FPS (n = 57) and 2-FPS (n = 76) groups.The 4-FPS group showed higher median DAP (599.9 cGy cm; interquartile range [IR], 371.4-1337.5 cGy cm vs. 392.0 cGy cm; IR, 289.7-591.4 cGy cm; P < .01), longer median fluoroscopic time (24.4 min; IR, 17.5-34.9 min vs. 15.1 min; IR, 10.7-20.1 min; P < .01), and higher median ED (1.1 mSv; IR, 0.7-2.5 mSv vs. 0.7 mSv; IR, 0.6-1.1 mSv; P < .01) compared with the 2-FPS group. No major procedure-related complications such as cardiac tamponade were observed in either group. Over follow-up durations of 331 ± 197 days, atrial tachyarrhythmia recurred in 20 patients (35.1%) in the 4-FPS group and in 27 patients (35.5%) in the 2-FPS group (P = .96). Kaplan-Meier survival analysis revealed no significant different between the 2 groups (log rank, P = .25).In conclusion, both the 4-FPS and 2-FPS settings were feasible and emitted a relatively low level of radiation compared with that historically reported for DAP in a conventional fluoroscopy setting.

Medical devices: from licensing to coverage. highlights from Argentina, Brazil, Colombia and Mexico

OBJECTIVES

To describe and compare the requirements for medical devices licensing and reimbursement in four Latin-American countries.

METHODS

We conducted a literature search in major databases, and generic Internet engines, and interviewed key informants.

RESULTS

We included all publications describing regulation and/or coverage and enriched them with key informant's interviews. We found that licensing processes are similar. The decision-making process for coverage is not formally different than the one used for drugs. Although countries differ, Brazil, Colombia and Mexico have an explicit process informed by Health Technology Assessment. In general, coverage policies are defined for procedures and don´t specify device brand or model, and for that reason they may reimburse without explicit one by one device evaluation.

CONCLUSIONS

The process for licensing and reimbursement is broadly similar but less stringent than that for drugs. It allows the adoption of medical devices without individual comprehensive assessment.

Near zerO fluoroscopic exPosure during catheter ablAtion of supRavenTricular arrhYthmias: the NO-PARTY multicentre randomized trial

AIMS

Aim of this study was to compare a minimally fluoroscopic radiofrequency catheter ablation with conventional fluoroscopy-guided ablation for supraventricular tachycardias (SVTs) in terms of ionizing radiation exposure for patient and operator and to estimate patients' lifetime attributable risks associated with such exposure.

METHODS AND RESULTS

We performed a prospective, multicentre, randomized controlled trial in six electrophysiology (EP) laboratories in Italy. A total of 262 patients undergoing EP studies for SVT were randomized to perform a minimally fluoroscopic approach (MFA) procedure with the EnSiteTMNavXTM navigation system or a conventional approach (ConvA) procedure. The MFA was associated with a significant reduction in patients' radiation dose (0 mSv, iqr 0-0.08 vs. 8.87 mSv, iqr 3.67-22.01; P < 0.00001), total fluoroscopy time (0 s, iqr 0-12 vs. 859 s, iqr 545-1346; P < 0.00001), and operator radiation dose (1.55 vs. 25.33 µS per procedure; P < 0.001). In the MFA group, X-ray was not used at all in 72% (96/134) of cases. The acute success and complication rates were not different between the two groups (P = ns). The reduction in patients' exposure shows a 96% reduction in the estimated risks of cancer incidence and mortality and an important reduction in estimated years of life lost and years of life affected. Based on economic considerations, the benefits of MFA for patients and professionals are likely to justify its additional costs.

CONCLUSION

This is the first multicentre randomized trial showing that a MFA in the ablation of SVTs dramatically reduces patients' exposure, risks of cancer incidence and mortality, and years of life affected and lost, keeping safety and efficacy.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01132274.

Reduction of Fluoroscopy Time and Radiation Dosage During Catheter Ablation for Atrial Fibrillation

Radiofrequency catheter ablation has become the treatment of choice for atrial fibrillation (AF) that does not respond to antiarrhythmic drug therapy. During the procedure, fluoroscopy imaging is still considered essential to visualise catheters in real-time. However, radiation is often ignored by physicians since it is invisible and the long-term risks are underestimated. In this respect, it must be emphasised that radiation exposure has various potentially harmful effects, such as acute skin injury, malignancies and genetic disease, both to patients and physicians. For this reason, every electrophysiologist should be aware of the problem and should learn how to decrease radiation exposure by both changing the setting of the system and using complementary imaging technologies. In this review, we aim to discuss the basics of X-ray exposure and suggest practical instructions for how to reduce radiation dosage during AF ablation procedures.

Safety and Feasibility of a Minimally Fluoroscopic Approach for Ventricular Tachycardia Ablation in Patients With Structural Heart Disease: Influence of the Ventricular Tachycardia Substrate

BACKGROUND

We sought to evaluate the safety and feasibility of a minimally fluoroscopic approach using the CARTOUNIVU module during scar-related ventricular tachycardia (VT) ablation.

METHODS AND RESULTS

Consecutive patients with structural heart disease undergoing VT ablation using the CARTOUNIVU module were prospectively included and classified depending on their VT substrate: (1) ischemic VT (IVT) and (2) nonischemic VT and depending on the presence of an epicardial access. Radiation exposure parameters and major and minor procedure-related complications were registered. A near-zero fluoroscopy exposure was defined as those procedures with an effective dose ≤1 mSv. A total of 44 VT ablation procedures were performed in 41 patients (22 IVT and 19 nonischemic VT). The use of the CARTOUNIVU module resulted in low levels of radiation exposure: median total fluoroscopy time and effective dose of 6.08 (1.51-12.36) minutes and 2.15 (0.58-8.22) mSv, respectively. Patients with IVT had lower radiation exposure than patients with nonischemic VT (total fluoroscopy time, 2.53 [1.22-11.22] versus 8.51 [5.55-17.34] minutes; P=0.016). Epicardial access was associated with significantly higher levels of radiation exposure. Complications occurred in 4.9% patients, none of them being related to the use of the image integration tool. A near-zero fluoroscopy ablation could be performed in 14 of 44 procedures (32%), 43% of IVT procedures, and 50% of procedures with endocardial access only.

CONCLUSIONS

The use of the CARTOUNIVU module during scar-related VT ablation resulted in low levels of radiation exposure. A near-zero fluoroscopy approach can be achieved in up to half of the procedures, especially in IVT patients with endocardial ablation.