Improve Catheter Stability Research Articles

Ablation in Atrial Fibrillation with Ventricular Pacing Results in Similar Spatial Catheter Stability as Compared to Ablation in Sinus Rhythm with Atrial Pacing.

Improved catheter stability is associated with decreased arrhythmia recurrence after atrial fibrillation (AF) ablation. Recently, atrial voltage mapping in AF was demonstrated to correlate better with scar as compared to mapping in sinus rhythm (SR). However, it is unknown whether ablation of persistent AF in sinus rhythm with atrial pacing or in atrial fibrillation with ventricular pacing results in differences in catheter stability or arrhythmia recurrence. We analyzed 53 consecutive patients undergoing first-time persistent AF ablation with pulmonary vein and posterior wall isolation: 27 were cardioverted, mapped, and ablated in sinus rhythm with atrial pacing, and 26 were mapped and ablated in AF with ventricular pacing. Ablation data was extracted from the mapping system and analyzed using custom MATLAB software to determine high-frequency (60Hz) catheter excursion as a novel metric for catheter spatial stability. There was no difference in catheter stability as assessed by maximal catheter excursion, mean catheter excursion, or contact force variability between the atrial-paced and ventricular-paced patients. Ventricular-paced patients had significantly greater mean contact force as compared to atrial-paced patients. Contact-force variability demonstrated poor correlation with catheter excursion. One year arrhythmia-free survival was similar between the atrial paced and ventricular paced patients. For patients with persistent AF, ablation in AF with ventricular pacing results in similar catheter stability and arrhythmia recurrence as compared to cardioversion and ablation in sinus rhythm with atrial pacing. Given the improved fidelity of mapping in AF, mapping and ablating during AF with ventricular pacing may be preferred.

Rapid pacing and high-frequency jet ventilation additively improve catheter stability during atrial fibrillation ablation.

Catheter stability during atrial fibrillation ablation is associated with higher ablation success rates. Rapid cardiac pacing and high-frequency jet ventilation (HFJV) independently improve catheter stability. Simultaneous modulation of cardiac and respiratory motion has not been previously studied. The objective of this study was to determine the effect of simultaneous heart rate and respiratory rate modulation on catheter stability. Forty patients undergoing paroxysmal atrial fibrillation ablation received ablation lesions at 15 prespecified locations (12 left atria, 3 right atria). Patients were randomly assigned to undergo rapid atrial pacing for either the first or the second half of each lesion. Within each group, half of the patients received HFJV and the other half standard ventilation. Contact force and ablation data for all lesions were compared among the study groups. Standard deviation of contact force was the primary endpoint defined to examine contact force variability. Lesions with no pacing and standard ventilation had the greatest contact force standard deviation (5.86 ± 3.08 g), compared to lesions with pacing and standard ventilation (5.45 ± 3.28 g; P < .01) or to lesions with no pacing and HFJV (4.92 ± 3.00 g; P < .01). Lesions with both pacing and HFJV had the greatest reduction in contact force standard deviation (4.35 ± 2.81 g; P < .01), confirming an additive benefit of each maneuver. Pacing and HFJV together was also associated with a reduction in the proportion of lesions with excessive maximum contact force (P < .001). Rapid pacing and HFJV additively improve catheter stability. Simultaneous pacing with HFJV further improves catheter stability over pacing or HFJV alone to optimize ablation lesions.

General anesthesia improves contact force and reduces gap formation in pulmonary vein isolation: a comparison with conscious sedation.

Compared to conscious sedation (CS), the use of general anesthesia (GA) in pulmonary vein isolation (PVI) is associated with a lower recurrence rate of atrial fibrillation (AF). GA may improve catheter stability and mapping system accuracy compared to CS, but its influence on contact force (CF) parameters during ipsilateral PVI has not previously been investigated. The study population comprised 176 consecutive patients (107 in GA group and 69 in CS group) with AF who underwent their first PVI procedure. We retrospectively assessed CF parameters, force-time integral (FTI), FTI/wall thickness during anatomical ipsilateral PVI and long-term outcome after ablation. Complete PVI with single continuous circular lesions around the ipsilateral PVs was achieved in 54 patients (50.5%) in the GA group but only 24 patients (34.8%) in the CS group (P = 0.04). The distribution of gaps did not differ between the groups. All CF parameters were significantly higher in the GA group than in the CS group (average CF: 19.4 ± 8.7 vs. 16.7 ± 7.7g, P < 0.0001; FTI: 399.0 ± 262.5 vs. 293.9 ± 193.4gs, P < 0.0001; FTI/wall thickness: 155.5 ± 106.1 vs. 115.7 ± 85.5gs, P < 0.0001). GA was associated with lower AF recurrence rate in patients with paroxysmal AF but not with persistent AF. Compared with CS, GA improves CF parameters, FTI and FTI/wall thickness, and reduced gap formation after ipsilateral PVI.

A randomized prospective mechanistic cardiac magnetic resonance study correlating catheter stability, late gadolinium enhancement and 3 year clinical outcomes in robotically assisted vs. standard catheter ablation.

AimsTo prospectively compare cardiac magnetic resonance late gadolinium enhancement (LGE) findings created by standard vs. robotically assisted catheter ablation lesions and correlate these with clinical outcomes.Methods and resultsForty paroxysmal atrial fibrillation patients (mean age 54 ± 13.8 years) undergoing first left atrial ablation were randomized to either robotic-assisted navigation (Hansen Sensei® X) or standard navigation. Pre-procedural, acute (24 h post-procedure) and late (beyond 3 months) scans were performed with LGE and T2W imaging sequences and percentage circumferential enhancement around the pulmonary vein (PV) antra were quantified. Baseline pre-procedural enhancements were similar in both groups. On acute imaging, mean % encirclements by LGE and T2W signal were 72% and 80% in the robotic group vs. 60% (P = 0.002) and 76%(P = 0.45) for standard ablation. On late imaging, the T2W signal resolved to baseline in both groups. Late gadolinium enhancement remained the predominant signal with 56% encirclement in the robotic group vs. 45% in the standard group (P = 0.04). At 6 months follow-up, arrhythmia-free patients had an almost similar mean LGE encirclement (robotic 64%, standard 60%, P = 0.45) but in recurrences, LGE was higher in the robotic group (43% vs. 30%, P = 0.001). At mean 3 years follow-up, 1.3 procedures were performed in the robotic group compared with 1.9 (P < 0.001) in the standard to achieve a success rate of 80% vs. 75%.ConclusionRobotically assisted ablation results in greater LGE around the PV antrum. Effective lesions created through improved catheter stability and contact force during initial treatment may have a role in reducing subsequent re-do procedures.

29Characterising the relationship between force and catheter stability during manual and robotic paroxysmal AF ablation

Introduction: Optimal catheter contact force (CF) is associated with better lesion creation and improved outcomes for the ablation of paroxysmal atrial fibrillation (pAF). However it is unknown whether this is in part attributable to improved catheter stability. Method: MAST-AF is a prospective randomized controlled trial ([NCT01583855][1]) of M anual versus robotic control with the A migo Remote Catheter System (Catheter Robotics Inc.), using the S mart T ouch catheter and Carto 3 (Biosense Webster), in first time p AF ablation. All patients had point-by-point L and R WACA (wide area circumferential ablation) around ipsilateral pairs of pulmonary veins, with the operator blinded to CF. Energy was delivered at 40W throughout. The 3D location of the ablation catheter tip was recorded during RF delivery, and tip displacement calculated as the Euclidean distance between each consecutive sample. The corresponding CF at that time point was also extracted. All data was grouped according to Human / Robot and L / RWACA, and sorted by CF. Data was analysed visually by percentile, and the correlation coefficient relating force and catheter displacement was calculated on log-transformed data using Matlab (R2014a, Mathworks). Results: 6452 ablation points were analysed from 14 manual and 16 robotic subjects, totalling 294,099 CF/displacement data pairs. Visual evaluation (see figure 1) shows that when considering human or robot in isolation, overall variation in displacement across CF appears similar. However in both L and RWACA (essentially independent groups), a complex but consistent relationship for the displacement spread (IQR) is shown; specifically, at the extremes of force, robotic displacement variation is similar to or more than that of the human, with the reverse occurring in the central force range. The correlation coefficient, its confidence intervals, and statistical significance (r, CIs, p) were calculated for: Human LWACA (0.022, 0.014-0.029, <0.0001); Human RWACA (0.031, 0.021-0.038, <0.0001); Robot LWACA (0.011, 0.0040-0.018, 0.0022); and Robot RWACA (-0.045, -0.038 to -0.052, <0.0001). The robot RWACA group uniquely demonstrates a significant negative correlation, suggesting that robotic RWACA tends to provide greater stability as CF rises when compared with a manual procedure, and is concordant with our previous analysis showing higher CF application patterns for this particular group. Conclusions: CF is inversely correlated with catheter stability during WACA for pAF, except for Amigo ablation of the RWACA, where higher CF may be achievable due to superior robotic stability. Overall, for typical target CF ranges, Amigo assistance may improve catheter stability compared to manual ablation. ![Graphic][2] Figure 1 CF vs catheter displacement between human and robotic L and R WACA. Box and whisker plots show 10th, 25th, 50th (median), 75th and 90th percentiles. Dotted lines indicates IQRs. CF groups of <100 measurements were excluded. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT01583855&atom=%2Feuropace%2F16%2Fsuppl_3%2Fiii12.2.atom [2]: /embed/inline-graphic-1.gif

First in-human robotic rotor ablation for atrial fibrillation

Pulmonary vein isolation (PVI) is the cornerstone of most atrial fibrillation (AF) ablation procedures. Recent studies demonstrate that in AF, rapidly activating spiral-circuits called ‘rotors’ can be localized with computational-mapping during an electrophysiological study. Radiofrequency ablation at the rotor may result in AF termination. Remote robotic-navigation (RN) is designed to improve catheter stability and decrease radiation exposure. We report the first in-human rotor-mapping with a novel 64-electrode basket catheter (FIRMap®, …

Anaesthetist support during sedation for patients undergoing minimally invasive procedures outside the operating room

Anaesthetist support during sedation for patients undergoing minimally invasive procedures outside the operating room

Robotic endovascular surgery

The purpose of this review is to compare conventional endovascular procedures and the robotic endovascular approach in aortic aneurysm repair. Despite advantages over open surgery, conventional endovascular surgery has limitations. To develop an alternative, efforts have been focused on robotic endovascular systems. Two of the 3 studies comparing procedure times demonstrated reduced procedure time in the robotic group, by 6 times (p < 0.05). One study demonstrated that robotic procedures reduced fluoroscopic exposure time by 12 minute (p < 0.001). Three in-vitro studies showed that the number of movements required in robotic surgery was reduced up to 10 times (p < 0.05). One of 2 studies measuring robotic performance score showed a better performance score in the robotic endovascular group (p = 0.007). These results demonstrate that the robotic technique has multiple advantages over the conventional procedure, including improved catheter stability, a shorter learning curve, reduced procedure time, and better performance in cannulating tortuous vessels. However, robotic endovascular technology may be limited by the cost of the system, the size of the catheter, and the setup time required preoperatively. Further comparative studies between conventional and robotic approaches regarding cost-effectiveness, safety, and performance in cases involving complex anatomy and fenestrated stent grafts are essential. Nevertheless, this revolutionary technology is increasingly popular and may be the next milestone in endovascular surgery.

Study Design of the Man and Machine Trial: A Prospective International Controlled Noninferiority Trial Comparing Manual with Robotic Catheter Ablation for Treatment of Atrial Fibrillation

Pulmonary vein isolation (PVI) has become the cornerstone procedure for the treatment of symptomatic drug-resistant atrial fibrillation (AF). At the present time, circumferential PVI (CPVI) using irrigated radiofrequency (RF) is the mostly used ablation technique. However, for CPVI, precise catheter navigation and excellent catheter stability is crucial thereby requiring experienced operators. Robotic navigation systems have been introduced to facilitate catheter navigation and to improve catheter stability, therefore potentially increasing procedural success and making CPVI accessible to less experienced operators. To date, no prospective randomized trial has evaluated the efficacy and safety of CPVI using RNS compared to manually performed ablation. In this prospective international multicenter noninferiority trial, 258 patients with either paroxysmal or short-standing persistent AF will be randomized for comparison of PVI using either manual or robotic ablation. In all patients, CPVI will be performed using irrigated RF ablation in combination with a 3D mapping system. The primary endpoint of the trial is the absence of AF or atrial tachycardia without antiarrhythmic drug therapy during 12-month follow-up. Secondary endpoints will be evaluation of periprocedural complications and procedural data such as procedure time, fluoroscopy time, as well as the incidence of esophageal injury assessed by endoscopy within 48 hours after the procedure. The "Man and Machine Trial" is the first prospective international randomized controlled multicenter noninferiority trial to compare manually performed CPVI with robotically navigated CPVI, evaluating both the safety and efficacy of the 2 techniques during a 12-month follow-up period.

Robotic assistance and general anaesthesia improve catheter stability and increase signal attenuation during atrial fibrillation ablation

Recurrent arrhythmias after ablation procedures are often caused by recovery of ablated tissue. Robotic catheter manipulation systems increase catheter tip stability which improves energy delivery and could produce more transmural lesions. We tested this assertion using bipolar voltage attenuation as a marker of lesion quality comparing robotic and manual circumferential pulmonary vein ablation for atrial fibrillation (AF). Twenty patients were randomly assigned to robotic or manual AF ablation at standard radiofrequency (RF) settings for our institution (30 W 60 s manual, 25 W 30 s robotic, R30). A separate group of 10 consecutive patients underwent robotic ablation at increased RF duration, 25 W for 60 s (R60). Lesions were marked on an electroanatomic map before and after ablation to measure distance moved and change in bipolar electrogram amplitude during RF. A total of 1108 lesions were studied (761 robotic, 347 manual). A correlation was identified between voltage attenuation and catheter movement during RF (Spearman's rho -0.929, P < 0.001). The ablation catheter was more stable during robotic RF; 2.9 ± 2.3 mm (R30) and 2.6 ± 2.2 mm (R60), both significantly less than the manual group (4.3 ± 3.0 mm, P < 0.001). Despite improved stability, there was no difference in signal attenuation between the manual and R30 group. However, there was increased signal attenuation in the R60 group (52.4 ± 19.4%) compared with manual (47.7 ± 25.4%, P = 0.01). When procedures under general anaesthesia (GA) and conscious sedation were analysed separately, the improvement in signal attenuation in the R60 group was only significant in the procedures under GA. Robotically assisted ablation has the capability to deliver greater bipolar voltage attenuation compared with manual ablation with appropriate selection of RF parameters. General anaesthesia confers additional benefits of catheter stability and greater signal attenuation. These findings may have a significant impact on outcomes from AF ablation procedures.

How to achieve durable pulmonary vein isolation: Use the force

How to achieve durable pulmonary vein isolation: Use the force

Remote navigation systems in electrophysiology

Today, atrial fibrillation (AF) is the dominant indication for catheter ablation in big electrophysiologists (EP) centres. AF ablation strategies are complex and technically challenging. Therefore, it would be desirable that technical innovations pursue the goal to improve catheter stability to increase the procedural success and most importantly to increase safety by helping to avoid serious complications. The most promising technical innovation aiming at the aforementioned goals is remote catheter navigation and ablation. To date, two different systems, the NIOBE magnetic navigation system (MNS, Stereotaxis, USA) and the Sensei robotic navigation system (RNS, Hansen Medical, USA), are commercially available. The following review will introduce the basic principles of the systems, will give an insight into the merits and demerits of remote navigation, and will further focus on the initial clinical experience at our centre with focus on pulmonary vein isolation (PVI) procedures.

Remote magnetic navigation system provides a superior catheter stability in acquisition of His bundle electrogram

Catheter stability is a key prerequisite for a successful EP procedure. Remote magnetic navigation system (RMNS) was recently introduced for the manipulation of EP catheters. It may provide an improved catheter stability but this has not been tested prospectively. We performed a prospective cross-over study which compares the amplitude and stability of the His-electrogram obtained by catheters using RMNS vs conventional manual catheter placement. His-electrograms were continuously recorded for 3 min with a conventional His mapping catheter and magnetically tipped catheter capable of alignment in the direction of an externally controlled magnetic field (0.08-0.1 Tesla) in the same patient. First 100 beats of each recording were used for data analysis. The amplitudes of each set of His-electrograms were measured and compared in microvolts. Coefficient of variation of the measured His-signal amplitude was calculated for each beat. Miller's test for the equality of the coefficients of variation and Levene's test of homogeneity of variance were used for statistical analysis. Fourteen patients (6 males; aged 48+/-25 years) were included in the study. His-electrograms were more stable and homogenous with RMNS than manual method in 10/14 patients. Pooled variance of all RMNS recordings was significantly less than pooled variance of manual recordings (p=0.01). His-electrogram recording using RMNS is more stable and homogeneous than traditional manual method in most patients. These data indicate a superior catheter stability with RMNS.