Catheter Ablation Of Typical Atrial Flutter Research Articles

Benefits from catheter ablation in patients with pulmonary hypertension: Recent advances.

Supraventricular tachycardia (SVT) is a frequent complication of pulmonary hypertension (PH). The most prevalent SVTs are atrial fibrillation (AF) and typical atrial flutter (AFL), followed by focal and macroreentrant atrial tachycardia (AT) and nodal arrhythmia (AV nodal reentry tachycardia or AV reentry tachycardia). SVT is frequently associated with functional deterioration and right ventricular failure in PH patients. According to some data, reestablishing sinus rhythm is associated with clinical improvement. Catheter ablation of typical AFL, nodal tachyarrhythmias, or other less complex focal ATs have been shown to be feasible, acutely effective, and safe in patients with PH. However, the long-term clinical outcome is modified by the recurrence of index arrhythmia and the onset of a new SVT. Due to right atrial dilatation, technical issues can arise when ablation is carried out. The role of catheter ablation in patients with AF or more complex AT is even less effective. The results mirror the success rate in the general AF population with non-paroxysmal AF. However, the data is limited, and electrophysiological procedures are also more often complicated by specific adverse events in a severely frail population. Despite these limitations, catheter ablation is the treatment of choice in less complex SVT, but the indications for AF ablation must be more individualized.

Half-Normal Saline vs Normal Saline for Cavotricuspid Isthmus-Dependent Atrial Flutter Ablation

BackgroundCavotricuspid isthmus (CTI) ablation requires permanent bidirectional block to prevent recurrence of typical atrial flutter (AFL). Catheter irrigation with half-normal saline (HNS) produces larger and deeper lesions in experimental models compared with normal saline (NS). This study was performed to compare the clinical efficacy and safety of HNS vs NS irrigation for typical AFL ablation. MethodsSixty patients undergoing catheter ablation of typical AFL were randomized 1:1 to NS or HNS irrigation. Endpoints included time to CTI block, acute reconnection, incidence of steam pops, and recurrence of AFL during follow-up. ResultsBaseline characteristics were comparable between both arms. The mean age of the patients was 68.5 ± 8.2 years, 20% were female, and 32% had atrial fibrillation before being enrolled. Bidirectional CTI block was obtained in all patients with no difference in time to CTI block between groups (6.4 ± 4.4 minutes vs 7.6 ± 4.5 minutes, respectively; P = 0.15). There was a trend to less acute reconnection in the HNS group compared with NS (13.3% vs 26.6%; P = 0.46). Steam pops occurred in 4 patients using HNS vs none in the NS group, but no major complications were observed. During the follow-up, rate of AFL recurrence was similar between groups (6.7% with HNS vs 10% with NS; P = 0.5). There was no difference in time to recurrence (7.6 ± 6.9 vs 4.9 ± 4.5 months; P = 0.6). ConclusionsIn this small pilot randomized controlled trial, there was no significant difference between HNS and NS for CTI ablation; however, HNS may increase the incidence of steam pops.

Recurrent atrial arrhythmia in a randomised controlled trial comparing contact force-guided and contact force-blinded ablation for typical atrial flutter.

Contact force (CF)-guided catheter ablation (CA) is a novel technology developed to improve efficacy and reduce complications. In a randomised controlled trial (RCT), we previously documented that after 3months, rate of persistent conduction block was similar with and without using CF while performing CA for typical atrial flutter (AFL). Clinical effect of CF on recurrent arrhythmia is unknown. Our objective is to study recurrent atrial arrhythmia during 12-month follow-up in a RCT investigating whether CF-guided CA for typical AFL is superior to CF-blinded CA. Patients were randomised 1:1 to CA guided by CF (intervention group) or blinded to CF (control group). After 12months, patients attended clinical check-up preceded by a 5-day ambulatory Holter monitor recording. Primary outcome was any recurrent atrial arrhythmia ≥ 30s within 12months and documented in 12-lead ECG or Holter monitor recording. We included 156 patients, four patients withdrew consent and two died during follow-up. Thus, 150 patients were included in final analysis. Recurrent arrhythmia was detected in 36 of 77 (47%) patients in the intervention group, and 32 of 73 patients (44%) in the control group (p = 0.51). Atrial fibrillation was detected in 23 (30%) and 29 (40%) patients in the intervention and control groups respectively. AFL was detected in 11 (14%) and 5 (7%) patients in the intervention and control groups respectively. Contact force-guided ablation for typical atrial flutter does not reduce recurrent atrial arrhythmia after 12-month follow-up as compared with ablation blinded for contact force.

The use of half normal saline during catheter ablation of typical atrial flutter has no impact on the time to achieve bidirectional block

Abstract Background Achieving bidirectional block (BB) is generally considered to be the endpoint in the ablation of typical atrial flutter (AFL), however acute reconnection is common. Recent data suggest that deeper ablation lesions may be created by decreasing the irrigant ionic concentration using half normal saline (HNS) delivered through an open irrigated ablation catheter compared with normal saline (NS). We sought to assess whether the use of HNS was associated with a more rapid achievement of BB and less reconnections compared with NS. Methods Patients were randomly allocated to catheter ablation with either NS or HNS using a 4-mm irrigated catheter at a power setting of 30 W. Ablation approach employing either a maximum voltage guided (MVG) or empiric cavo-tricuspid isthmus (CTI) line was performed aiming for BB that was confirmed by double potentials separated by an isoelectric line measuring ≥110 ms and evidence of conduction block using differential pacing. Study was powered to an endpoint of acute reconnection within 30 mins. Results A total of 60 patients underwent catheter ablation for typical AFL with either HNS (n=30) or NS (n=30). There were no significant differences between the two groups in terms of patient age (68±7 yrs HNS vs. 68±10 yrs NS) and BMI (31±7 HNS vs 31±5 NS). BB was achieved in all patients. The MVG approach was employed in 28/60 patients. Acute reconnection was observed in 11 patients (18%); 4 in HNS vs 7 in NS group (ns). The mean RF time to achieve BB was 386±262 seconds in HNS vs 456±270 seconds in NS (p=0.21). The approach to CTI ablation showed a significant difference in time to BB: Time to block in MVG cases was 264±143 seconds vs 567±273 in empiric CTI line cases. Figure 1 demonstrates the time to block in both approaches with the choice of irrigant not appearing to impact the time to BB. There were 4 steam pops in the HNS arm and 0 steam pops observed in the NS arm. There were no significant complications in either arm. Conclusion Irrigation with HNS resulted in no statistically significant reduction in duration of RF time or improvement in acute outcomes over NS in the atrial flutter population. Reduction in duration of RF time was driven by MVG approach. However, acute reconnections were higher in NS group, all 4 steam pops occurred in HNS arm. Figure 1 Funding Acknowledgement Type of funding source: None

A randomized trial of contact force in atrial flutter ablation.

Contact force (CF) sensing has emerged as a tool to guide and improve outcomes for catheter ablation (CA) for cardiac arrhythmias. The clinical benefit on patient outcomes remains unknown. To study whether CF-guided CA for typical atrial flutter (AFL) is superior to CA not guided by CF. In a double-blinded controlled superiority trial, we randomized patients 1:1 to receive CA for typical AFL guided by CF (intervention group) or blinded to CF (control group). In the intervention group, a specific value of the lesion size index (LSI), estimating ablation lesions size was targeted for each ablation lesion. Patients underwent electrophysiological study (EPS) after 3 months to assess occurrence of the primary endpoint of re-conduction across the cavo-tricuspid isthmus (CTI). We included 156 patients with typical AFL, median age was 68 [interquartile range (IQR) 61-74] years and 120 (77%) patients were male. At index procedure median LSI was higher in the intervention group [6.4 (IQR 5.1-7) vs. 5.6 (IQR 4.5-6.9), P < 0.0001]. After 3 months, 126 patients (58 in intervention group) underwent EPS for primary endpoint assessment. Thirty (24%) patients had CTI re-conduction, distributed with 15 patients in each treatment group (P = 0.62). We observed no difference between treatment groups with regard to fluoroscopy, ablation, or procedure times, nor peri-procedural complications. Contact force-guided ablation does not reduce re-conduction across the CTI after 3 months, nor does CF-guided ablation shorten fluoroscopy, ablation, or total procedure times.

THE USE OF HALF NORMAL SALINE TO SHORTEN TIME REQUIRED TO ACHIEVE BIDIRECTIONAL BLOCK FOR THE CATHETER ABLATION OF TYPICAL ATRIAL FLUTTER

Complete bidirectional block (BB) of the cavotricuspid isthmus (CTI) during catheter ablation of atrial flutter (AFL) is an established endpoint. Standard irrigated radiofrequency ablation is performed using normal saline (NS, 0.9%), yet the use of lower ionic concentration with half normal saline (HNS, 0.45%) has previously led to the creation of wider and deeper lesions ex vivo. It has yet to be elucidated as to whether these results could be used to alter ablation outcomes in human subjects. We compared the use of HNS to NS for catheter ablation of typical AFL with respect to the time taken to achieve BB, radiofrequency time, and recurrence of conduction within 30 minutes. The incidence of intraoperative complications, including steam pops and pericardial effusions, was also recorded. Patients were randomized to catheter ablation with either NS or HNS using a 4mm irrigated catheter at a power setting of 30W. Ablation was performed with the aim of restoring sinus rhythm in patients who were in AFL. BB was confirmed by double potentials separated by an isoelectric line measuring >= 110ms and evidence of conduction block using differential pacing. A total of 30 patients underwent catheter ablation for typical AFL (14 HNS, 16 NS). Sinus rhythm and bidirectional block were achieved in all patients. The two groups were comparable with respect to patient age (69±10 years HNS vs. 71±15 years NS) and duration of AFL (7±6 months HNS vs. 8±5 months NS). The mean time to achieve BB using RF was 10.4±2.6 mins using HNS compared with 14.5±3.8 mins using NS (p=0.01). There were slightly more steam pops amongst patients in the HNS arm (2 HNS vs. 0 NS). Conversely, recurrences of conduction were higher for patients in the NS group as compared to HNS, 3 vs. 0 respectively. Overall, there were no significant adverse events observed in either arm. The time taken to achieve BB was shorter when HNS was used as compared to NS. This was not associated with any major complications in either group, but with an increased frequency of recurrences of conduction in patients undergoing catheter ablation with NS.

THE USE OF HALF NORMAL SALINE AS AN IRRIGANT FOR THE CATHETER ABLATION OF TYPICAL RIGHT SIDED ATRIAL FLUTTER

Ablation of typical atrial flutter (AFL) can be challenging and achievement of bidirectional block can be limited by complex anatomy and a lack of transmural lesions. Recent data suggest that deeper ablation lesions may be created by decreasing the irrigant ionic concentration using half normal saline (HNS) delivered through open irrigated RFA than by using normal saline (NS). We sought to test whether the use of HNS in an irrigated catheter resulted in a more rapid achievement of bidirectional block (BB) compared with NS. Patients were randomly allocated to catheter ablation with either NS or HNS using a 4mm irrigated catheter at a power setting of 30W. Ablation was performed aiming for the restoration of sinus rhythm in patients who were in AFL and bidirectional block as confirmed by double potentials separated by an isoelectric line measuring 110ms and evidence of conduction block using differential pacing. A total of 24 patients underwent catheter ablation for typical AFL (12 HNS, 12 NS). Sinus rhythm and bidirectional block were achieved in all patients. There were no significant differences between the two groups in terms of patient age (72 +/- 12 years HNS; 69 +/- 14 years NS) and duration of AFL (8 +/- 6 months HNS; 9 +/- 5 months NS). The mean duration to achieve BB using RF was 12.4 +/- 3.8 mins using HNS compared with 17.5 +/- 4.2 mins using NS (p=0.01). There were 2 steam pops in the HNS arm and 0 steam pops in the NS arm (ns). There were no significant complications in either arm. Irrigation with HNS results in achievement of bidirectional block using a shorter duration of RF compared with NS. This may be associated with a higher incidence of steam pops although this did not result in any adverse events to the patient.

P892Predictors of new-onset atrial fibrillation after catheter-ablation of typical atrial flutter

P892Predictors of new-onset atrial fibrillation after catheter-ablation of typical atrial flutter

CHA₂DS₂-VASc Score in the Prediction of Ischemic Stroke in Patients after Radiofrequency Catheter Ablation of Typical Atrial Flutter.

PurposeDespite undergoing successful catheter ablation of typical atrial flutter (AFL), patients remain at increased risk for ischemic stroke. However, data on risk prediction tools for the development of stroke after AFL ablation are lacking. This study investigates whether CHA2DS2-VASc score is useful for predicting ischemic stroke after successful ablation of typical AFL.Materials and MethodsA total of 293 patients (236 men, mean age 56.1±13.5 years) who underwent successful radiofrequency catheter ablation for typical AFL were included in this study. The clinical end point was occurrence of ischemic stroke during follow-up after AFL ablation.ResultsDuring the follow-up period (60.8±45.9 months), ischemic stroke occurred in 18 (6%) patients at a median of 34 months (interquartile range, 13–65 months). CHA2DS2-VASc score [hazard ratio 2.104; 95% confidence interval (CI), 1.624–2.726; p<0.001] was an independent predictor for the occurrence of stroke after AFL ablation. The area under the receiver operating characteristic curve for CHA2DS2-VASc score was 0.798 (95% CI, 0.691–0.904). The CHA2DS2-VASc score could be used to stratify patients into two groups with different incidences of ischemic stroke (1.6% vs. 14.4%, p<0.001) at a cutoff value of 2.ConclusionCHA2DS2-VASc score is useful in a prediction model for the risk of stroke after catheter ablation of typical AFL.

Uninterrupted Warfarin for Periprocedural Anticoagulation in Catheter Ablation of Typical Atrial Flutter: A Safe and Cost‐Effective Strategy

Many patients undergoing catheter ablation of atrial flutter (AFL) require periprocedural anticoagulation. We compared a strategy of conversion to low molecular weight heparin (LMWH) periprocedure to uninterrupted warfarinization in a nonrandomized, case-controlled study. One hundred and one consecutive patients requiring periprocedural anticoagulation for catheter ablation of typical AFL were studied. The first 51 patients underwent conversion to LMWH (enoxaparin 1 mg/kg bd) with a warfarin pause (LMWH group), the subsequent 50 continued with uninterrupted oral anticoagulation (Warfarin group). Primary endpoint was a composite of major and minor bleeding complications and groin symptoms. Fewer patients in the Warfarin group reached the primary endpoint (36.0% vs 56.8%, P = 0.013). Four patients in the LMWH group but no patient in the Warfarin group required hospital admission for bleeding-related complications. Cost analysis showed mean cost per patient of anticoagulation with LMWH to be pounds sterling 100.9 (95% CI 94.46-107.30) compared to pounds sterling 10.23 (4.49-15.97) in the Warfarin group (P < 0.0001). Transesophageal echocardiography (TEE) was performed prior to ablation in 11 patients in the Warfarin group and in 3 patients in the LMWH (P = 0.019). When TEE costs were included, costs were pounds sterling 125.00 ($188.25) (96.80-153.60) for the LMWH strategy and pounds sterling 108.5 ($163.40) (54.92-162.1) for the Warfarin group (P < 0.0001). Catheter ablation of typical AFL without interruption of warfarin appears safer and more cost-effective than periprocedural conversion to LMWH. It could be used as a routine anticoagulation strategy for the ablation of right-sided arrhythmias.