Mapping and ablation of clinical spontaneous perimitral atrial tachycardias using an ultra-high-resolution mapping system.

BACKGROUND: Perimitral atrial tachycardias (PMATs) are common atrial tachycardias (ATs), yet their mechanisms vary. OBJECTIVE: The purpose of this study was to characterize clinical spontaneous PMATs using an ultra-high-resolution (UHR) mapping system. METHODS: The study included 32 consecutive PMATs in 31 patients who had undergone AT mapping/ablation using a UHR mapping system. RESULTS: Six, 10, 11, and 5 PMATs occurred in cardiac intervention-naïve (group A), post-lateral/posterior mitral isthmus linear ablation (group B), post-atrial fibrillation ablation without mitral isthmus linear ablation (group C), and post-cardiac surgery (group D) patients, respectively. Group A patients tended to be older, more likely were female, and had sinus node or atrioventricular conduction disturbances more frequently. A 12-lead synchronous isoelectric interval was observed in 15 PMATs (46.9%). Coronary sinus activation was proximal to distal or distal to proximal except in 3 PMATs with straight patterns due to epicardial gaps. Left atrial anterior/septal wall (LAASW) low-voltage areas were smallest in group B. Slow conduction areas (SCAs) were identified in 26 PMATs (81.2%) and were located on the LAASW in all group A and group D patients. Conduction velocity in the SCAs was slowest in group B. In group B, all PMATs were terminated by single applications, and the gaps were located epicardially in 5 of 10 (50%). Anterior (n = 23) or lateral/posterior (n = 9) mitral isthmus linear block was successfully created without any complications in all. Twenty-five concomitant ATs among 18 patients (58.1%) also were eliminated. During a median of 20.0 (11.0-40.0) months of follow-up, 28 patients (90.3%) were free from any atrial tachyarrhythmias. CONCLUSION: An UHR mapping-guided approach with identification of the individual tachycardia mechanism should be the preferred strategy given the distinct and complex arrhythmia mechanisms.

Comparison of ablation outcomes of the second ablation procedure for recurrent atrial fibrillation using an ultra-high-resolution mapping system and conventional mappings system.

BACKGROUND: The utility of an ultra-high-resolution electroanatomical mapping system (UHR-EAM, Rhythmia) for repeat atrial fibrillation (AF) ablation has not been evaluated. HYPOTHESIS: A second AF ablation procedure performed using UHR-EAM may demonstrate different outcomes compared with that using a conventional electroanatomical mapping system (C-EAM, CARTO3). METHOD: This observational study enrolled consecutive patients who underwent a second AF ablation procedure using UHR-EAM (n = 103) and C-EAM (n = 153). The second ablation procedure included re-isolation of reconnected pulmonary veins (PVs) and elimination of clinical or induced non-PV AF triggers and atrial tachycardia (AT). Other empirical ablations were additionally conducted at the discretion of the operators. RESULTS: Re-isolation of PVs was achieved in 196 patients who had ≥1 left atrial-PV reconnection. The elimination rate of AT was higher in the UHR-EAM group than the C-EAM group (87% vs 65%, P = .040), while that of non-PV AF triggers was similar (63% vs 63%, P = 1.00). The UHR-EAM demonstrated shorter radiofrequency application time (21.8 ± 16.8 vs 28.0 ± 21.3 minutes, P = .017), but longer fluoroscopic time (26.2 ± 12.6 vs 21.4 ± 9.3 minutes, P = .0001). No severe complication developed. The total 1-year AF/AT-free survival rates were similar between the two groups (off AADs, 59.2% vs 56.2%, P = .62; on AADs, 65.0% vs 69.3%, P = .49). CONCLUSION: The efficacy and safety outcomes of repeat AF ablation using UHR-EAM was comparable to those using C-EAM.

High-resolution, real-time, and nonfluoroscopic 3-dimensional cardiac imaging and catheter navigation in humans using a novel dielectric-based system.

BACKGROUND: Catheter navigation and 3-dimensional (3D) cardiac mapping are essential components of minimally invasive electrophysiological procedures. OBJECTIVE: The purpose of this study was to develop a novel 3D mapping system (KODEX - EPD, EPD Solutions, Best, The Netherlands) that measures changing electric field gradients induced on intracardiac electrodes to enable catheter localization and real-time 3D cardiac mapping. METHODS: We first validated the accuracy of the system's measurement and localization capabilities by comparing known and KODEX - EPD-measured distances and locations at 12 anatomical landmarks in both the atria and ventricles of 4 swine. Next, in vivo images of 3D porcine cardiac anatomy generated by KODEX - EPD and widely used CARTO 3 system (Biosense Webster, Inc., Diamond Bar, CA) were compared with gold standard computed tomography images acquired from the same animals. Finally, 3D maps of atrial anatomy were created for 22 patients with paroxysmal atrial fibrillation (Dielectric Unravelling of Radiofrequency ABLation Effectiveness trial). RESULTS: First, the mean error between known and measured distances was 1.08 ± 0.11 mm (P < .01) and the overall standard deviation between known and measured locations in 12 areas of the porcine heart was 0.35 mm (P < .01). Second, an expert comparison of 3D image quality revealed that KODEX - EPD is noninferior to CARTO 3. Third, the system enabled 3D imaging of atrial anatomy in humans, provided real-time images of atrioventricular valves, and detected important anatomical variations in a subset of patients. CONCLUSION: The KODEX - EPD system is a novel 3D mapping system that accurately detects catheter location and can generate high-resolution images without the need for preacquired imaging, specialty catheters, or a point-by-point mapping procedure.

The seamless integration of three-dimensional rotational angiography images into electroanatomical mapping systems to guide catheter ablation of atrial fibrillation.

It is important to visually confirm radiofrequency ablation lesions during atrial fibrillation (AF) ablation for procedural efficiency, which requires the integration of a three-dimensional (3D) left atrial image reconstructed from computed tomography (CT) or a magnetic resonance imaging. However, an EP Navigator allows seamless integration of 3D anatomy obtained through 3D rotational angiography (3D-ATG) into an electroanatomical mapping system. We hypothesized that 3D-ATG can be used during AF ablation while significantly reducing the effective dose (ED) and without compromising image morphology compared to a 3D-CT image. Organ dose was measured at 37 points with a radiophotoluminescence glass dosimeter inserted in an anthropomorphic Rando Phantom. The ED was calculated by multiplying the organ dose by the tissue weighting factor. The dose-area product (DAP)-to-ED conversion factor was calculated by measuring the DAP during radiation exposure. The ED for the CT examination was estimated from the dose-length product with a conversion factor of 0.014. ED was calculated from DAP measurements in 114 patients undergoing AF ablation using 3D-ATG. The DAP-to-ED conversion factor for 3D-ATG was 2.4 × 10-4 mSv/mGy cm2 in our hospital. The mean DAP for all patients was 7777 ± 1488 mGy cm2 for the 3D-ATG of the left atrium. The corresponding ED for 3D-ATG was 1.9 ± 0.4 mSv. The ED for CT examinations was 13.6 ± 4.2 mSv (P < 0.001). 3D-ATG can be used during AF ablation while significantly reducing the ED and without compromising image morphology.

The best of two worlds? Pulmonary vein isolation using a novel radiofrequency ablation catheter incorporating contact force sensing technology and 56-hole porous tip irrigation.

AIMS: This study aimed to evaluate feasibility and safety as well as 1-year clinical outcome of pulmonary vein isolation (PVI) using a unique radiofrequency ablation catheter ("Thermocool SmartTouch SurroundFlow"; STSF) incorporating both, contact force (CF) sensing technology and enhanced tip irrigation with 56 holes, in one device. METHODS: A total of 110 patients suffering from drug-refractory atrial fibrillation underwent wide area circumferential PVI using either the STSF ablation catheter (75 consecutive patients, study group) or a CF catheter with conventional tip irrigation ("Thermocool SmartTouch", 35 consecutive patients, control group). For each ablation lesion, a target CF of ≥ 10-39 g and a force time integral (FTI) of > 400 g s was targeted. RESULTS: Acute PVI was achieved in all patients with target CF obtained in > 85% of ablation points when using either device. Mean procedure time (131.3 ± 33.7 min in the study group vs. 133.0 ± 42.0 min in the control group; p = 0.99), mean fluoroscopy time (14.0 ± 6 vs. 13.5 ± 6.6 min; p = 0.56) and total ablation time were not significantly different (1751.0 ± 394.0 vs. 1604.6 ± 287.8 s; p = 0.2). However, there was a marked reduction in total irrigation fluid delivery by 51.7% (265.52 ± 64.4 vs. 539.6 ± 118.2 ml; p < 0.01). The Kaplan-Meier estimate 12-month arrhythmia-free survival after the index procedure following a 3-month blanking period was 79.9% (95% CI 70.4%, 90.4%) for the study group and 66.7% for the control group (95% CI 50.2%, 88.5%). This finding did not reach statistical significance (p = 0.18). Major complications occurred in 2/75 patients (2.7%; one pericardial tamponade and one transient ischemic attack) in the study group and no patient in the control group (p = 18). CONCLUSION: PVI using the STSF catheter is safe and effective and results in beneficial 1-year clinical outcome. The improved tip irrigation leads to a significant reduction in procedural fluid burden.

Clinical outcomes of AF patients treated with the first and second-generation of circular mapping and ablation catheter: insights from a real world multicenter experience.

PURPOSE: Complete pulmonary vein isolation (PVI) is the best documented target for catheter ablation, and different technologies have shown comparable outcomes. The multielectrode phased-RF/duty cycled (PhRF/DC) pulmonary vein ablation catheter (PVAC) and its second generation (PVAC-GOLD) have shown promising clinical results in single and multicenter experiences. Our aim is to assess and compare the safety and efficacy in the real clinical practice among two generations of circular PhRF/DC catheters by performing PVI in patients suffering from recurrent atrial fibrillation (AF). METHODS: Eighty-four AF patients treated with PVAC and 64 with PVAC-GOLD were prospectively followed in five Italian cardiology centers in the mainframe of the 1STOP-ClinicalService project. RESULTS: Fluoroscopic and total procedure time were significantly different in the two groups. In particular, in the PVAC-GOLD group, the mean fluoroscopic time was 22.8 ± 12.7 min vs 31.6 ± 18.9 in the PVAC group (p = 0.002), and the mean total procedure duration was 117.6 ± 36.0 vs 147.4 ± 40.6, in the PVAC-GOLD group and the PVAC group, respectively (p = 0.001). Only two out of 148 patients reported a peri-procedural complication. Over 20.9 ± 12.0 months of follow-up, AF recurrence occurred in 58 patients. Kaplan-Meier freedom from AF recurrence did not differ between the two groups (64.1 ± 10% in the PVAC group vs 68.2 ± 9% in the PVAC-GOLD group at 1 year, p = ns). CONCLUSIONS: In our multicenter analysis, AF ablation using two generations of circular PhRF/DC catheters is safe and effective. No difference was observed in terms of safety and efficacy of the AF ablation between the two catheters, with the mean procedural time being shorter in the PVAC-GOLD group.

Wire- and needle potentials facilitating transseptal puncture.

BACKGROUND: Transseptal puncture for left heart interventions became a routine procedure guided by fluoroscopy and echocardiography. The use of intracardiac potentials derived from the sheath-transseptal-needle/guidewire-combination may provide helpful information to increase safety of this procedure. METHODS AND RESULTS: We recorded the intracardiac potentials from the sheath-transseptal-needle/guidewire-combination during the transseptal puncture procedure in 31 consecutive patients (mean age 67.2±8.2years; 21 in sinus rhythm, 10 in atrial fibrillation) designated for ablation of atrial fibrillation by the Cryo-balloon ® technique (Medtronic, Minnesota, USA). The EP-Navigator ® 3-D-image integration tool (Philips Healthcare, Hamburg, Germany) was used for visualization of the device position in relation to the cardiac structures. Typical and reproducible potentials could be derived in all patients for the different device localizations at transseptal puncture procedure. Especially the transition from the muscular interatrial septum into the fossa ovalis could be easily depicted by the changes of both morphology and magnitude of the atrial signal (6.1±2.3mV in sinus rhythm [SR]/3.5±0.9mV in atrial fibrillation [AF] at the muscular interatrial septum and 0.5±0.2mV in SR/0.5±0.1mV in AF in the fossa ovalis). CONCLUSIONS: The crucial steps of a transseptal procedure can be verified by typical changes (morphology and amplitude) of the intracardiac signals derived from the sheath-transseptal-needle/guidewire-combination in patients with sinus rhythm as well as in atrial fibrillation.

Utility and safety of the SafeSept™ transseptal guidewire for electrophysiology studies with catheter ablation in pediatric and congenital heart disease.

PURPOSE: The atrial transseptal procedure is used in catheter ablation of left-sided arrhythmias. Studies in adult patients have shown the SafeSept™ transseptal guidewire (SSTG) to be effective in atrial transseptal procedures. We analyzed our 5-year experience with SSTG use in pediatric and congenital heart disease patients undergoing catheter ablation. METHODS: This is a single-center retrospective analysis of patients undergoing catheter ablation from 2009 to 2014. We identified all procedures where SSTG was used for atrial transseptal or trans-baffle access. Success of transseptal access and complications were recorded and compared to the standard transseptal approach without the SSTG. RESULTS: One hundred twenty-seven patients underwent 132 attempted atrial transseptal or trans-baffle procedures using SSTG. Median age was 14 (1.2-38) years. Arrhythmia substrates included AV reentrant tachycardia (90.2%), atrial tachycardia (4.5%), ventricular tachycardia (2.3%), and AV nodal reentrant tachycardia (2.3%). Transseptal or trans-baffle access was successful in 96.2% of the SSTG cases compared to 98.9% in the standard transseptal group without SSTG (p = NS). The youngest patient with successful atrial transseptal procedure using SSTG was 4 years old. SSTG was used to successfully cross a surgically created atrial baffle in a patient who had undergone the Mustard procedure. There was one major complication in both groups, 0.8% in the SSTG group compared to the standard transseptal group without SSTG, 1.1% (p = NS). The major complication in the SSTG group occurred when the SSTG crossed the aorta into the coronary artery system and mimicked placement in the left atrial appendage, with subsequent placement of a transseptal sheath into the aorta, requiring sternotomy and surgical intervention. CONCLUSIONS: SSTG is effective for use in atrial transseptal and surgical trans-baffle access in pediatric and congenital heart disease patients. Placement of the SSTG into the pulmonary vein is necessary to avoid major complications, and if not achieved requires additional methods to determine appropriate left atrial placement.

Isolated Disruption of the Right Coronary Artery Following a Steam Pop during Cavotricuspid Linear Ablation with a Contact Force Catheter.

A 70-year-old woman with persistent atrial fibrillation underwent pulmonary vein isolation and linear ablation with a contact sensor catheter. During cavotricuspid isthmus ablation, a steam pop resulted in cardiac tamponade, and the patient developed severe hypotension despite successful pericardial puncture and minimal residual pericardial effusion. Right coronary artery angiography revealed extravasal contrast medium accumulation posterior of the Crux Cordis. Emergent cardiac surgery confirmed isolated disruption of the artery in the absence of additional heart perforation. Although contact sensor catheters may reduce complications, steam pops can still occur and result in dramatic complications.

Cryoballoon ablation for pulmonary vein isolation in patients with atrial fibrillation: preliminary results using novel short-tip cryoballoon.

PURPOSE: In this study, we aimed to report our preliminary experience regarding the impact of the novel short-tip (ST) cryoballoon (CB) on procedural efficacy and signal quality during pulmonary vein (PV) isolation for both paroxysmal and persistent atrial fibrillation. METHODS: Between March, 2015, and August, 2015, we enrolled a total of 64 patients (47 patients male, 73 %) with a mean age of 60 ± 11 years. In the study population, 31 patients (48 %) underwent PVI using Advance (ADV) CB and 33 (52 %) patients with ST CB. In all patients, a 28-mm balloon was used. RESULTS: Acute procedural success rates were 100 % for the entire study population. A statistically insignificant increase in the percentage of PV signal recordings was observed with ST CB in all PVs compared to ADV CB [88 vs. 81 % for left superior PV (LSPV), 82 vs. 78 % for left inferior PV (LIPV), 85 vs. 84 % for right superior PV (RSPV), 82 vs. 71 % for right inferior PV (RIPV), p < 0.05]. Additionally, the difference in minimum temperature reached during the procedure per PV was not statistically significant between ST CB and ADV CB except the LIPV (LSPV -44.2 ± 5.9 vs. -45.6 ± 5.3 °C, p = 0.970; LIPV -38.7 ± 4.6 °C vs -44.6 ± 6.8 °C, p < 0.001; RSPV -45.6 ± 7.4 °C vs.-47.2 ± 6.1 °C, p = 0.168; RIPV -41.4 ± 5.1 °C vs.-43.7 ± 6.3 °C, p = 0.360). Time to isolation for each PV was similar between ST and ADV CB (p > 0.05). CONCLUSION: Our preliminary findings indicated similar acute procedural success for the novel ST CB compared with second generation ADV CB. The increase in the ratio of PV signal recordings obtained during the PVI using the novel ST CB was not significant.

First results and follow-up of a second-generation circular mapping and ablation catheter.

PURPOSE: Pulmonary vein isolation with radiofrequency energy is widely used as a strategy for catheter ablation of atrial fibrillation (AF). Anatomically designed catheters have been developed to increase the efficiency of AF ablation procedures. The second-generation circular ablation catheter, PVAC GOLD, was re-designed to improve energy delivery and mitigate emboli. We investigated the procedural efficiency, biophysics, and chronic efficacy of PVAC GOLD in patients with AF. METHODS: We consecutively enrolled 40 patients (60 ± 11 years) with highly symptomatic, drug refractory AF. The first 20 patients were treated with the first-generation PVAC. The subsequent 20 patients were treated with the second-generation PVAC GOLD catheter. All patients were followed up at 3, 6, and 12 months. RESULTS: All 164 targeted PVs were successfully isolated. Ablations performed with PVAC GOLD showed a significant reduction in total number of ablations needed for PVI, fluoroscopy, and procedure times compared to PVAC (34.7 ± 7.0 vs. 27.0 ± 6.5; p = 0.009), fluoroscopy (29.5 ± 9.5 vs. 23.4 ± 7.0; p = 0.026), and procedure time (93.8 ± 18.9 vs. 83.1 ± 10.6; p = 0.033). PVAC GOLD showed improved biophysics including a reduction of low power ablations and an increase in mean effective energy delivery. At 12 months follow-up, AF recurrence rates were comparable in the two groups (35 vs. 30 %; p = 0.735). There were no adverse events. CONCLUSIONS: The redesigned PVAC GOLD catheter demonstrates a reduction in radiofrequency ablation and procedure time and improved biophysics while maintaining chronic efficacy compared to the first-generation PVAC.

Improved visualisation of real-time recordings during third generation cryoballoon ablation: a comparison between the novel short-tip and the second generation device.

BACKGROUND: The third-generation Cryoballoon Advance Short-tip (CB-ST) has been designed with a 40 % shortened tip length compared with the former second generation CB advance device (CB-A). Ideally, a shorter tip should permit an improved visualisation of real-time recordings in the pulmonary vein (PV) due to a more proximal positioning of the inner lumen mapping catheter. We sought to compare the incidence of visualisation of real-time recordings in patients having undergone ablation with the CB-ST with patients having received CB-A ablation. METHODS: All patients having undergone CB ablation using CB-ST technology and the last 500 consecutive patients having undergone CB-A ablation were analysed. Exclusion criteria were the presence of an intracavitary thrombus, uncontrolled heart failure, moderate or severe valvular disease, and contraindications to general anaesthesia. RESULTS: A total of 600 consecutive patients (58.1 ± 12.9 years, 64 % males) were evaluated (100 CB-ST and 500 CB-A ablations). Real-time recordings were significantly more prevalent in the CB-ST population compared with CB-A group (85.7 vs 67.2 %, p < 0.0001). Real-time recordings could be more frequently visualised in the CB-ST group in all types of veins (LSPV 89 vs 73.4 %, p = 0.0005; LIPV 84 vs 65.6 %, p = 0.0002; RSPV 87 vs 67.4 %, p < 0.0001; RIPV 83 vs 62.4 %, p < 0.0001). CONCLUSION: The rate of visualisation of real-time recordings is significantly higher during third-generation CB-ST ablation if compared to the second-generation CB-A device. Real-time recordings can be visualised in approximately 85.7 % of veins with this novel cryoballoon.

Analysis of catheter contact force during atrial fibrillation ablation using the robotic navigation system: results from a randomized study.

PURPOSE: Contact with cardiac tissue is an important determinant of lesion efficacy during atrial fibrillation (AF) ablation. The Sensei X™ robotic navigation system (RNS) (Hansen Medical, Mountain View, CA, USA) has been validated for contact force (CF) sensing expressed in grams (g). The Thermocool® SmartTouch™ catheter enables the measurement of catheter tip CF and direction inside the heart. We aimed to investigate the catheter CF with and without RNS during pulmonary vein isolation (PVI) procedures. METHODS: Eighty patients with symptomatic AF (56 males, age 63 ± 18) were enrolled in this study. Fifty-seven patients had paroxysmal AF and 23 early persistent AF. All procedures were performed with the Thermocool® SmartTouch™ ablation catheter. Forty patients were randomized to perform PVI with the Sensei X™ RNS (group 1), while in the other 40 patients (group 2), PVI was performed without the RNS. RESULTS: AF ablation was performed successfully in all patients without complications, while contact force was kept in the established 10-40 g range. A significantly higher CF was documented on the PVs in group 1 compared to group 2. The 1-year freedom from AF recurrence was higher in group 1 compared to group 2 (90 vs. 65 %, p = 0.04). Moreover, a significant reduction of fluoroscopy time was noted in the RNS group (13 ± 10 vs. 20 ± 10 min, respectively, p = 0.05). CONCLUSIONS: The Sensei X™ RNS permits a significantly higher CF during transcatheter AF ablation with a low rate of AF recurrence at clinical follow-up.

Impact of Contact Force Monitoring in Acute Pulmonary Vein Isolation Using an Anatomic Approach. A Randomized Study.

BACKGROUND: The impact of contact force (CF) monitoring in pulmonary vein (PV) isolation after a circumferential anatomic ablation (CAA) is unknown. We analyze the usefulness of CF monitoring in acute PV isolation and procedure parameters using a CAA. METHODS: Fifty patients with paroxysmal atrial fibrillation were randomized into CF-on (CF >10 grams; n = 25) or CF-off (CF blinded; n = 25) groups. We performed a first round of CAA with a ThermoCool(®) SmartTouch(®) catheter blinded to the LASSO(®) catheter (Biosense Webster, Diamond Bar, CA, USA), with radiofrequency (RF) lesions tagged with the VisiTag(™) Module. After the CAA, each PV was reviewed with the LASSO(®) catheter recording the segments with gaps. RESULTS: All the PVs were isolated with a CAA in 20 patients of the CF-on versus eight of the CF-off (P = 0.001). Of the 45 segments with gaps in the left PVs, 38 were from the CF-off (P = 0.0001). Of the eight segments with gaps in the right PVs, seven were from the CF-off (P = 0.06). The CF in the left PVs was higher in the CF-on (16.3 ± 3.2 grams vs 10.5 ± 4.3 grams; P = 0.0001) and similar in the right PVs (17.6 ± 3.6 grams vs 15.2 ± 5.3 grams; P = 0.08). All of the gaps were closed with additional RF LASSO(®) -guided touch-up. Procedure and fluoroscopy times were shorter in the CF-on (139 ± 24 minutes vs 157 ± 32 minutes and 20 ± 6 minutes vs 24 ± 7 minutes; both P = 0.039). At 12 months the patients free of AF recurrence was 84% CF-on versus 75% CF-off (log-rank P = 0.4) [corrected]. CONCLUSIONS: In paroxysmal atrial fibrillation, a CAA guided by CF reduces PV gaps and shortens the procedure parameters at the expense of the left PVs.

Electroanatomic mapping systems (CARTO/EnSite NavX) vs. conventional mapping for ablation procedures in a training program.

BACKGROUND: Three-dimensional electroanatomic mapping (EAM) systems reduce radiation exposure when radio frequency catheter ablation (RFCA) procedures are performed by well-trained senior operators. Given the steep learning curve associated with complex RFCA, trainees and their mentors must rely on multiple imaging modalities to maximize safety and success, which might increase procedure and fluoroscopy times. The objective of the present study is to determine if 3-D EAM (CARTO and ESI-NavX) improves procedural outcomes (fluoroscopy time, radio frequency time, procedure duration, complication, and success rates) during CA procedures as compared to fluoroscopically guided conventional mapping alone in an academic teaching hospital. METHODS: We analyzed a total of 1070 consecutive RFCA procedures over an 8-year period for fluoroscopic time stratified by ablation target and mapping system. Multivariate logistic regression and adjusted odds ratios were calculated for each variable. RESULTS: No statistically significant differences in acute success rates were noted between conventional and 3-D mapping cases [CARTO (p = 0.68) or ESI-NavX (p = 0.20)]. Moreover, complication rates were also not significantly different between CARTO (p = 0.23) and ESI-NavX (p = 0.53) when compared to conventional mapping. Procedure, radio frequency, and fluoroscopy times were significantly longer with CARTO and ESI-NavX versus conventional mapping [fluoroscopy time: CARTO, 28.3 min; ESI, 28.5 min; and conventional, 24.3 min; p < 0.001)]. CONCLUSIONS: The use of 3-D EAM systems during teaching cases significantly increases radiation exposure when compared with conventional mapping. These findings suggest a need to develop alternative training strategies that enhance confidence and safety during catheter manipulation and allow for reduced fluoroscopy and procedure times during RFCA.

Evaluation of the Achieve Mapping Catheter in cryoablation for atrial fibrillation: a prospective randomized trial.

PURPOSE: The purpose of this study is to establish the role of Achieve Mapping Catheter in cryoablation for paroxysmal atrial fibrillation (PAF) in a randomized trial. METHODS: A total of 102 patients undergoing their first ablation for PAF were randomized at 2:1 to an Achieve- or Lasso-guided procedure. Study patients were systematically followed up for 12 months with Holter monitoring. Primary study endpoint was acute procedure success. Secondary endpoint was clinical outcomes assessed by AF free at 6 and 12 months after the procedure. RESULTS: Of 102 participants, 99 % of acute procedure success was achieved. Significantly shorter procedure duration with the Achieve-guided group than with the Lasso-guided group (118 ± 18 vs. 129 ± 21 min, p < 0.05) was observed as was the duration of fluoroscopy (17 ± 5 vs. 20 ± 7 min, p < 0.05) by subgroup analysis focused on procedures performed by experienced operators. In the whole study patients, procedure and fluoroscopic durations were similar in the Achieve- (n = 68) and Lasso-guided groups (n = 34). Transient phrenic nerve weakening was equally prevalent with the Achieve and Lasso. No association was found between clinical outcomes and the mapping catheter used. The use of second-generation cryoballoon (n = 68) reduced procedure time significantly compared to the first-generation balloon (n = 34); more patients were free of AF in the former than the latter group during follow-up. CONCLUSIONS: The use of the Achieve Mapping Catheter can reduce procedure and fluoroscopic durations compared with Lasso catheters in cryoablation for PAF after operators gained sufficient experience. The type of mapping catheter used does not affect procedure efficiency and safety by models of cryoballoon.

A novel intra-operative, high-resolution atrial mapping approach.

PURPOSE: A new technique is demonstrated for extensive high-resolution intra-operative atrial mapping that will facilitate the localization of atrial fibrillation (AF) sources and identification of the substrate perpetuating AF. METHODS: Prior to the start of extra-corporal circulation, a 8 × 24-electrode array (2-mm inter-electrode distance) is placed subsequently on all the right and left epicardial atrial sites, including Bachmann's bundle, for recording of unipolar electrograms during sinus rhythm and (induced) AF. AF is induced by high-frequency pacing at the right atrial free wall. A pacemaker wire stitched to the right atrium serves as a reference signal. The indifferent pole is connected to a steal wire fixed to subcutaneous tissue. Electrograms are recorded by a computerized mapping system and, after amplification (gain 1000), filtering (bandwidth 0.5-400 Hz), sampling (1 kHz) and analogue to digital conversion (16 bits), automatically stored on hard disk. During the mapping procedure, real-time visualization secures electrogram quality. Analysis will be performed offline. RESULTS: This technique was performed in 168 patients of 18 years and older, with coronary and/or structural heart disease, with or without AF, electively scheduled for cardiac surgery and a ventricular ejection fraction above 40 %. The mean duration of the entire mapping procedure including preparation time was 9 ± 2 min. Complications related to the mapping procedure during or after cardiac surgery were not observed. CONCLUSIONS: We introduce the first epicardial atrial mapping approach with a high resolution of ≥1728 recording sites which can be performed in a procedure time of only 9±2 mins. This mapping technique can potentially identify areas responsible for initiation and persistence of AF and hopefully can individualize both diagnosis and therapy of AF.

Usefulness of a crista catheter for 3-dimensional electroanatomical mapping of complex right atrial tachyarrhythmias.

PURPOSE: Right atrial (RA) tachyarrhythmias are not rare in patients with congenital heart disease and a history of cardiac surgery. This study investigated the usefulness of a crista catheter for 3-dimensional electroanatomical mapping of RA tachyarrhythmias. METHODS: We consecutively included 35 patients (age, 43.2 ± 15.6 years; 15 men) who underwent an electrophysiological study with 3-dimensional electroanatomical mapping for RA tachycardia or flutter. In 13 patients with atrial flutter, we recorded and compared the electrical sequence in the anterior and posterior portions of the RA lateral wall. We used a crista catheter as a mapping catheter for 3-dimensional mapping in 12 patients (crista group), a lasso catheter in 12 patients (lasso group), and an ablation catheter in 11 patients (ablation group). We compared the 3-dimensional mapping points, time, and speed (mapping points per minute) among the groups. RESULTS: Atrial flutter was confirmed as cavotricuspid isthmus-dependent in all patients whose two atrial electrical sequences were the same direction and as atypical (including scar-related and dual-loop) in all patients whose sequences were in the opposite direction. Mapping speed in the crista group was significantly faster than in the lasso and ablation groups: median (interquartile range) 44.0 (35.5-69.4) points/min, 23.7 (17.8-29.8) points/min, and 8.2 (4.8-11.0) points/min, respectively (p = 0.001). CONCLUSIONS: A crista catheter is useful for high-density 3-dimensional electroanatomical mapping of complex RA tachyarrhythmias. Comparison of the electrical sequences in the anterior and posterior portions of the RA lateral wall is helpful for differentiating between cavotricuspid isthmus-dependent and atypical atrial flutter.

Impact of catheter ablation with remote magnetic navigation on procedural outcomes in patients with persistent and long-standing persistent atrial fibrillation.

BACKGROUND: The objectives of this study were to assess the procedural outcomes of persistent and long-standing persistent atrial fibrillation (PsAF and L-PsAF) ablation guided by remote magnetic navigation (RMN), and to detect factors predicting acute restoration of sinus rhythm (SR) by ablation with RMN. METHODS: A total of 313 patients (275 male, age 59 ± 9.5 years) with PsAF (187/313) or L-PsAF (126/313) undergoing ablation using RMN were included. Patients' disease history, pulmonary venous anatomy, left atrial (LA) volume, procedure time, mapping plus ablation time, radiofrequency (RF) ablation time, fluoroscopy time, radiation dose, and complications were assessed. Stepwise regression was used to predict which variable could best predict acute restoration from AF to SR by ablation. RESULTS: Compared to PsAF, procedure time and RF ablation time were significantly increased in patients with L-PsAF (P = 0.01 and P < 0.001, respectively). No major complications occurred during the procedures in either PsAF or L-PsAF patients. Fifty five of 313 patients converted directly to SR by ablation. Compared to L-PsAF, the rate of SR restoration was significantly higher in PsAF (21 vs 12%, P = 0.03). Stepwise regression analysis showed LA volume was the primary parameter affecting SR restoration (P = 0.01). The LA volume of patients without direct SR restoration by ablation was 24% greater than that of patients with SR restoration (P < 0.001). CONCLUSIONS: Catheter ablation using RMN is a safe and effective method for PsAF and L-PsAF. LA volume could be a predictor of direct restoration of SR from sustaining AF by ablation using RMN.