Termination of slow-fast atrioventricular reentrant tachycardia by a single cryoablation of the slow pathway guided by a fractionation map.

This is a slow-fast atrioventricular nodal reentrant tachycardia (AVNRT) case wherein the fractionation map-guided cryoablation of the slow pathway (SP) successfully terminated the tachycardia. In this case, the Advisor™ HD Grid catheter and fractionation map in the EnSite™ X EP system with relatively high-sensitive settings were useful for detecting the target SP area. Direct AVNRT termination by cryomapping at the fractionated potential area might be a quick and safe ablation strategy, which may provide a new workflow for SP ablation.

Safety and effectiveness of intracardiac echocardiography in ventricular tachycardia ablation: a nationwide observational study.

Intracardiac echocardiography (ICE) utilized in conjunction with three-dimensional (3-D) mapping systems could enhance ventricular tachycardia (VT) ablation procedures. ICE has been increasingly used in VT ablation; however, the safety and effectiveness of VT ablation under the combined use of ICE remains unclear. The present study aimed to analyze the safety and short-term effects of VT ablation with or without ICE. We retrospectively enrolled patients who underwent initial VT ablation with a combination of ICE and a 3-D mapping system within 3 days of hospitalization and discharged from April 2011 to March 2017 using a nationwide Japanese inpatient database. Following enrollment, we conducted a propensity score-matching analysis to compare safety (in-hospital complications) and effectiveness (readmission within 30 days after discharge due to cardiovascular disease and readmissions within 30 days for repeat VT ablations) between patients who underwent VT ablation with (ICE group) and without ICE (non-ICE group). 3-D mapping systems were applied to both groups. We identified 5,804 eligible patients (1,272 and 4,532 patients in the ICE and non-ICE groups, respectively). One-to-one propensity score matching created a total of 1,147 pairs between the ICE and non-ICE groups. The ICE group showed a significantly lower prevalence of cardiac tamponade than the non-ICE group. There were no significant differences observed between the two groups regarding other outcomes concerning safety and effectiveness. Ventricular tachycardia ablation with ICE used in combination with a 3-D mapping system may reduce cardiac tamponade; however, no additional clinical advantages were noted in terms of safety and effectiveness.

Transseptal puncture without fluoroscopy using a radiofrequency needle: A case series.

BACKGROUND: The non-fluoroscopy approach with the use of a three-dimensional (3D) navigation system is increasingly recognized as a future technology in the treatment of arrhythmias. However, there are a limited number of articles published concerning transseptal puncture without the use of fluoroscopy. METHODS: Presented in this paper is the first series of patients (n = 10) that have undergone transseptal puncture without the use of fluoroscopy under transesophageal echocardiography control using a radiofrequency transseptal needle and a 3D navigation system. RESULTS: All patients were treated without complications. In 6 patients, re-pulmonary vein isolation was performed. In 5 cases, linear ablation of the left atrium for treatment of left atrial macro re-entry tachycardia was provided. In 2 patients, focal atrial tachycardia was treated, 1 patient underwent cavo tricuspidal isthmus (CTI) ablation and 1 patient, re-CTI ablation. The ablation of complex fragmented atrial electrograms was done in 2 patients. In 1 case, right atrial macro re-entry tachycardia was treated. CONCLUSIONS: Transseptal puncture without using fluoroscopy is safe and effective when using a radiofrequency needle, a 3D navigation system and transesophageal echocardiography.

Effectiveness of a 3D mapping benchmark for ablation in patients with atrioventricular nodal reentrant tachycardia.

BACKGROUND: Avoiding excessively fast junctional rhythm (JR) during slow pathway (SP) modification for atrioventricular nodal reentrant tachycardia (AVNRT) helps prevent serious atrioventricular block. This study investigated the usefulness of a predictive ablation point that lies near the boundary line between appropriate and excessively fast JRs with three-dimensional (3D) electroanatomical mapping in AVNRT patients. METHODS: Participants were 141 consecutive patients with common AVNRT who received anatomical ablation to an antegrade SP at our institution between August 2013 and December 2019. Patients were divided into two groups: Group A, treated using a location marker that predicts successful ablation sites in a 3D mapping system, and Group B, treated prior to the development of this marker and therefore without it. RESULTS: The average age was 61.9 ± 16.9 years, and 41.1% of patients were male. Excessively fast JRs appeared less frequently in Group A than in Group B, though this difference did not reach significance. The distance from the His bundle to the successful ablation point was significantly longer in Group A than in Group B (13.4 ± 4.5 vs 10.8 ± 4.4 mm, P < .01). The number of ablations near the successful ablation point was significantly lower in Group A (6.5 ± 5.2 vs 11.4 ± 9.9, P < .01), and a greater number of accelerated JRs at the successful ablation point were observed in Group A (46.9 ± 29.2 vs 32.8 ± 19.2, P < .01). CONCLUSION: Using our benchmark for a predictive successful ablation point in 3D mapping simplifies and improves common AVNRT ablation procedures.

Progress in zero-fluoroscopy implantation of cardiac electronic device.

Fluoroscopy is the imaging modality routinely used for cardiac device implantation. Due to the rising concern regarding the harmful effects of radiation exposure to both the patients and operation staffs, many efforts have been made to develop alternative techniques to achieve zero-fluoroscopy implantation. In this review, we describe the different methods aimed at avoiding the application of fluoroscopy in recent years, and evaluate their feasibility and safety in cardiac electronic device implantation.

Predictors of low voltage areas in persistent atrial fibrillation: is it really a matter of time?

BACKGROUND: Time has been postulated as an important factor for electrical remodeling of the left atrium (LA) in persistent atrial fibrillation (AF) ('AF begets AF'). However, it is still a matter of debate if structural changes are the cause or consequence of AF. We sought to determine the clinical and invasive parameters, which correlate with LA scar as determined by voltage mapping, in patients with persistent AF. METHODS: Seventy consecutive patients undergoing ablation of persistent (49%) or long-standing persistent AF (51%), between January 2013 and February 2014, were enrolled in the study. Besides clinical parameters, 2D echocardiographic assessment of LA size and LA pressure (LAP) after transseptal puncture was also considered. Bipolar endocardial signals with a mean voltage amplitude < 0.1 mV during AF were defined as LA scar. RESULTS: In the univariable analysis, LA scar was associated with age, gender, coronary artery disease (CAD), glomerular filtration rate (GFR), LA size and LAP. Arrhythmia duration, mild to moderate mitral regurgitation (MR), left ventricular dysfunction and left ventricular hypertrophy showed no significant correlation with atrial scar (all p > 0.05). In a multivariable regression model, LA scar area was independently associated with age, female gender and LA area. AF duration was not associated with LA scar. CONCLUSIONS: In this study, older age, greater LA area and female gender predicted the degree of LA scar, while other variables tested did not. In particular, we found no significant association between AF duration and LA scar.

Relationship between heart rate on atrioventricular node reentrant tachycardia sustaining and slow path position during procedure of slow path modified ablation using three-dimensional mapping system / 中国介入影像与治疗学

Objective: To observe the relationship between heart rate on atrioventricular node reentrant tachycardia (AVNRT) sustaining and slow path position during procedure of slow path modified ablation using three-dimensional mapping system. Methods: Modified ablation of slow pathway under three-dimensional mapping system was performed in 98 patients with slow-fast (S-F) AVNRT confirmed by invasive electrophysiology examination. The successful target (the site of slow-pathway) and standard His bundle were marked using three-dimensional mapping system, and the distance (Distance A) between the successful target and standard His bundle was measured. The relationship between heart rate in AVNRT and Distance A was analyzed. Results: Distance A was successfully obtained in 96 patients, including 64 tachycardia induced without infusion of isoproterenol, the heart rate was (179.77±29.22)bpm and relevant Distance A was (13.56±5.06)mm, also 32 tachycardia induced with infusion of isoproterenol, the heart rate was (174.91±17.41)bpm and relevant Distance A was (12.43±3.70)mm. No obvious correlation between heart rate and slow path position was found among the above 96 patients (rs=0.048, -0.190; P=0.705, 0.298). Conclusion: There was no obvious correlation between patient's heart rate on AVNRT sustaining and slow path position druing the procedure of slow path modified ablation using three-dimensional mapping system.

Substrate Mapping and Ablation for Ventricular Tachycardia in Patients with Structural Heart Disease: How to Identify Ventricular Tachycardia Substrate.

Catheter ablation for ventricular tachycardia (VT) has been increasingly used over the past two decades in patients with structural heart disease (SHD). In these individuals, a substrate mapping strategy is being more commonly applied to identify targets for VT ablation, which has been shown to be more effective versus targeting mappable VTs alone. There are a number of substrate mapping methods in existence that aim to explore potential VT isthmuses, although their success rates vary. Most of the reported electrogram-based mapping studies have been performed with ablation catheters; meanwhile, the use of multipolar mapping catheters with smaller electrodes and closer interelectrode spacing has emerged, which allows for an assessment of detailed near-field abnormal electrograms at a higher resolution. Another recent advancement has occurred in the use of imaging techniques in VT ablation, particularly in refining the substrate. The goal of this paper is to review the key developments and limitations of current mapping strategies of substrate-based VT ablation and their outcomes. In addition, we briefly summarize the role of cardiac imaging in delineating VT substrate.

Treatment of left accessory cardiac pathway conduction disorders using radiofrequency catheter ablation under the guidance of the Ensite NavX 3D mapping system: a retrospective study.

To investigate the effectiveness and safety of using the Ensite NavX three-dimensional (3D) mapping system during Radiofrequency catheter ablation (RFCA) of left accessory pathway (AP) disorders. A total of 227 patients having their left AP treated by RFCA, were classified into study group (n = 112) and the control group (n = 115). X-ray irradiation time and exposure doses during the course of the operations were recorded. Time taken to place the mapping catheter along with total duration of operations and procedural complications were compared. The X-ray irradiation time and exposure doses in the course of manipulating the ablation catheters were significantly lower in the study group compared to control (5.1 ± 2.3 min vs. 13.1 ± 3.1 min; P < 0.05 and 5.7 ± 2.6 mGy vs. 17.8 ± 4.3 mGy; P < 0.05, respectively). The total duration of operation was also significantly shorter in the study group compared to control (53.1 ± 18.8 min vs. 62.3 ± 20.6 min; P < 0.05). No procedural complications were reported in both groups. The irradiation time and exposure dose along with total operation duration was significantly reduced when the Ensite NavX mapping system was used during RFCA in comparison with traditional X-ray fluoroscopy method.

The application of 3D-reconstruction technique of atrial septum puncture trajectory in radiofrequency catheter ablation for atrial fibrillation / 介入放射学杂志

Objective To evaluate the safety and feasibility of reconstruction technique of atrial septum puncture trajectory with the help of three - dimensional mapping system in performing radiofrequency catheter ablation for atrial fibrillation. Methods Sixty- eight consecutive patients with atrial fibrillation received two times of atrial septum puncture under fluoroscopic guidance to perform radiofrequency catheter ablation. Carto 3, a three - dimensional mapping system, was employed to construct the real time left atrium and pulmonary vein anatomy by using a rapid anatomical mapping (FAM) model. Then, FAM model was used to construct the trajectory, along which the ablation catheter passed from left atrium through the long sheath to the right atrium and finally into the inferior vena cava. The safety and the feasibility of this catheter trajectory, which could allow the catheter repeatedly enter the left atrium, were evaluated. Results By using 3D-reconstruction technique of atrial septum puncture trajectory, the ablation catheter could repeatedly enter the left atrium at right anterior oblique position as well as at left anterior oblique position under zero X-ray fluoroscopy. The average time spent for the procedure was (12. 18±2. 28) seconds. No any complication occurred. Conclusion The reconstruction technique of atrial septum puncture trajectory with the help of three-dimensional mapping system is simple and feasible, the ablation catheter can repeatedly enter the left atrium, the X-ray exposure time spent for catheter ablation of atrial fibrillation can be greatly reduced. (J Intervent Radiol, 2018, 27: 204-206)

EnSite-NavX three-dimensional mapping-guided renal sympathetic denervation: An experimental study / 第二军医大学学报

Objective To explore the safety and efficacy of the renal sympathetic denervation under the guidance of EnSite-NavX three-dimensional mapping system. Methods A three-dimensional model of abdominal aorta and renal artery was constructed under the guidance of EnSite-NavX three-dimensional mapping in 6 healthy Guangxi Bama mini-pigs. Then a radiofrequency ablation catheter was put into the bilateral main trunks of renal artery and six points were marked within each trunk from far to near the heart. One side of the renal artery was ablated and the other received no ablation serving as control. The mini-pigs were followed up for 6 months after the procedure. The norepinephrine (NE) content in the renal tissues was detected by ELISA. Sympathetic nerve damage in the renal tissue of the ablation side was observed by Haematoxylin-Eosin staining. Results Modeling and unilateral renal sympathetic denervation were successfully performed in the six mini-pigs. Subcutaneous hematoma was formed after operation in one pig. None of the pigs had the complications such as renal artery stenosis, thrombopoiesis, or dissection. The NE content of ablation side was significantly lower than that of the opposite side ([170.13±52.60] ng/g vs [429.86±131.43] ng/g, P<0.05). Haematoxylin-Eosin staining showed broken epineurium and loss of axons in the renal sympathetic nerve of the ablation side. Conclusion A three-dimensional model of abdominal aorta and renal artery can be clearly constructed under the guidance of EnSite-NavX three-dimensional mapping. Renal sympathetic denervation can be achieved safely and effectively without fluoroscopy or renal arteriography under the navigation of NavX.

Feasibility of Transseptal Puncture Using a Nonfluoroscopic Catheter Tracking System.

BACKGROUND: Radiation exposure in the electrophysiology lab is a major occupational hazard to the electrophysiologists. A catheter localization system (MediGuide Technology, St. Jude Medical Inc., St. Paul, MN, USA) allows the integration of electroanatomical mapping and x-ray imaging, and has been shown to be effective in reducing radiation exposure during several electrophysiological procedures. We intended to evaluate the feasibility of this catheter tracking system to guide transseptal (TS) access. METHODS: The feasibility of performing TS puncture with MediGuide (MDG) was assessed in a prospective observational study in 16 patients undergoing radiofrequency ablation for atrial fibrillation. These patients were compared to 16 matched patients undergoing similar procedures during the same time frame using conventional approach. There were no differences in mean age, gender distribution, and body mass index between the two groups. Total duration of fluoroscopic exposure during TS puncture was compared between the two groups. RESULTS: All patients underwent successful TS puncture. Fluoroscopy time for double TS puncture using the MDG system was significantly lower than the control group (0.48 ± 0.17 minutes vs. 5.9 ± 0.65 minutes; P < 0.0001). No major complications occurred during the procedures in either group. CONCLUSIONS: TS puncture can be successfully performed using MDG, and results in significant reduction in radiation exposure.

Transcatheter radiofrequency ablation under the guidance of three-dimensional mapping for the treatment of complex cardiac arrhythmias / 介入放射学杂志

Objective To investigate the effectiveness and safety of transcatheter radiofrequency ablation guided by a three-dimensional mapping system (Ensite or Carto) for the treatment of complex cardiac arrhythmias. Methods A cohort of 123 consecutive hospitalized inpatients during the period from February 2006 to December 2008 were selected for this study. These patients suffered from various arrhythmias, including paroxysmal atrial fibrillation (n=58). Persistent or permanent atrial fibrillation (n=10), atrial flutter (n=13), atrial tachycardia (n=12) and ventricular tachycardia or frequent ventricular premature beats (n=30). Transcatheter radiofrequency ablation for arrhythmias was performed under the guidance of an EnSite3 000/NavX or Array mapping system in 80 cases, and under the guidance of a CARTO mapping system in the remaining 43 cases. Results Successful ablation of arrhythmias was obtained by single operation in 106 cases(86.18%). Including 59 cases with atrial fibriUation,11 cases with atrial flutter, 10 cases with atrial tachycardia, and 26 cases with ventricular tachycardia or premature ventricular beat. Ablation procedure was carried out and was successful in 10 cases with a successful rate of 94.31%, including 5 cases with atrial fibrillation. 1 case with recurred atrial flutter, 1 case with recurrent atrial tachycardia, and 3 cases with ventricular tachycardia or premature ventricular beat. After operation, complications occurred in 6 cases, including cardiac tamponade in 4 cases, distal embolism of the left anterior descending coronary artery in 1 case, and pulmonary embolism in 1 case. Conclusion Three-dimensional mapping system can clearly and stereoscopically display the cardiac structures. Therefore, this technique is of great value in guiding the transcatheter radiofrequency ablation for complex arrhythmias, in improving the success rate of ablation and in increasing the safety of the procedure.