Comparing Low-to-Zero Fluoroscopic Navigation Systems for AVNRT Catheter Ablation: A Network Meta-Analysis.

BACKGROUND: Low-to-zero fluoroscopic navigation systems lower radiation exposure which improves health outcomes. Conventional x-ray fluoroscopy (CF) has long been the standard to guide to catheter location for cardiac ablation. With advancements in technology, alternative safety navigation systems have been developed. Three primary modalities commonly utilized are three-dimensional electroanatomic mapping (3D-EAM), magnetic navigation system (MNS), and intracardiac echocardiography (ICE), all of which can reduce radiation exposure during the procedure. OBJECTIVE: We aim to compare the efficacy and safety among ICE, EAM, MNS, and CF in ablation of atrioventricular nodal reentrant tachycardia (AVNRT). METHODS: This is a meta-analysis consisting of observational studies and randomized controlled trials, which evaluated the performance of navigation systems of catheter ablation in AVNRT patients. Primary endpoint was to access the AVNRT recurrence after the procedure during follow-up periods. Secondary endpoints were technical success, fluoroscopic time, fluoroscopic dose area product, radiofrequency ablation time, and adverse events. Random-effect model was applied for pooled estimated effects of included studies. RESULTS: A total of 21 studies (21 CF, 2 ICE, 9 EAM, 11 MNS) including 1716 patients who underwent catheter ablation for AVNRT treatment were analyzed. Of these, 16 were observational studies and 5 were randomized controlled trials. PRIMARY OUTCOME: Point estimation of AVNRT recurrence showed ICE exhibited a pooled odds ratio (ORs) of 1.06 (95% confidence interval [CI]: 0.064-17.322), MNS with ORs of 0.51 (95% CI: 0.214-1.219], and EAM with ORs of 0.394 (95% CI: 0.119-1.305) when compared to CF. SECONDARY OUTCOMES: EAM had significant higher technical success with ORs of 2.781 (95% CI: 1.317-5.872) when compared to CF. Regarding fluoroscopy time, EAM showed the lowest time with mean differences (MD) of -10.348 min (95% CI: -13.385 to -7.3101) and P-score of 0.998. It was followed by MNS with MD of -3.712 min (95% CI: -7.128 to -0.295) and P-score of 0.586, ICE with MD of -1.150 min (95% CI: -6.963 to 4.662) with a P-score of 0.294 compared to CF, which has a P-score of 0.122. There were insignificant adverse events across the procedures. CONCLUSION: AVNRT ablation navigated by low-to-zero fluoroscopic navigation systems achieves higher efficacy and comparable safety to conventional fluoroscopywhile also reducing risk of radiation exposure time.

Comparative evaluation of intracardiac, transesophageal, and transthoracic echocardiography in the assessment of patent foramen ovale: A retrospective single-center study.

INTRODUCTION: Certain patent foramen ovale (PFO) characteristics, such as a large right-to-left shunt (RLS) or atrial septal aneurysm, identify patients who may receive the highest clinical benefit from percutaneous PFO closure. This study aimed to compare intracardiac echocardiography (ICE) with standard echocardiographic imaging in the evaluation of high-risk PFO characteristics and RLS severity in patients with PFO-associated stroke. METHODS: We conducted a retrospective review of all patients aged ≥18 years who underwent percutaneous PFO closure for PFO-associated stroke and received all three ultrasound-based cardiac imaging modalities and had interpretable results (N = 51). We then compared RLS severity, high-risk PFO characteristics, and the proportion of patients with a higher likelihood of PFO-associated stroke by ICE versus transthoracic echocardiogram (TTE) and transesophageal echocardiogram (TEE). RESULTS: The final cohort had a mean (±SE) age of 48.4 (±1.8) years and was predominantly female (58.8%). ICE was more likely to identify a large RLS versus TTE/TEE combined (66.7% vs. 45.1%; p = 0.03). The use of ICE resulted in significantly more patients being reclassified as having a higher likelihood of PFO-associated stroke (TTE vs. TEE vs. ICE: 10.4% vs. 14.6% vs. 25%; p = 0.03). A high-quality bubble study was found to be the single most important factor associated with identifying a larger RLS across all modalities (ρ [p]; TTE: 0.49 [<0.001], TEE: 0.60 [<0.001], ICE: 0.32 [0.02]). The presence of a hypermobile septum was associated with significantly greater RLS on ICE (ρ [p]: 0.3 [0.03]), especially with poor quality bubble studies (ρ [p]: 0.49 [0.02]). CONCLUSION: In this observational study of patients with PFO-associated stroke, ICE detected a large RLS more frequently than TTE and TEE; and reclassified some patients as having a higher likelihood of PFO-associated stroke.

Three-dimensional-guided and ICE-guided transseptal puncture for cardiac ablations: A propensity score match study.

INTRODUCTION: Transseptal puncture (TSP) is routinely performed for left atrial ablation procedures. The use of a three-dimensional (3D) mapping system or intracardiac echocardiography (ICE) is useful in localizing the fossa ovalis and reducing fluoroscopy use. We aimed to compare the safety and efficacy between 3D mapping system-guided TSP and ICE-guided TSP techniques. METHODS: We conducted a prospective observational study of patients undergoing TSP for left atrial catheter ablation procedures (mostly atrial fibrillation ablation). Propensity scoring was used to match patients undergoing 3D-guided TSP with patients undergoing ICE-guided TSP. Logistic regression was used to compare the clinical data, procedural data, fluoroscopy time, success rate, and complications between the groups. RESULTS: Sixty-five patients underwent 3D-guided TSP, and 151 propensity score-matched patients underwent ICE-guided TSP. The TSP success rate was 100% in both the 3D-guided and ICE-guided groups. Median needle time was 4.00 min (interquartile range [IQR]: 2.57-5.08) in patients with 3D-guided TSP compared to 4.02 min (IQR: 2.83-6.95) in those with ICE-guided TSP (p = .22). Mean fluoroscopy time was 0.2 min (IQR: 0.1-0.4) in patients with 3D-guided TSP compared to 1.2 min (IQR: 0.7-2.2) in those with ICE-guided TSP (p < .001). There were no complications related to TSP in both group. CONCLUSIONS: Three-dimensional mapping-guided TSP is as safe and effective as ICE-guided TSP without additional cost.

Intracardiac echocardiography techniques to identify ventricular arrhythmia substrate.

Intracardiac echocardiography (ICE) is increasingly used to facilitate catheter ablation of ventricular arrhythmias (VA). It allows intraprocedural recognition of myocardial substrate, optimization of catheter-tissue contact, identification of anatomical barriers to ablation, and early recognition of complications. In the era where the 3-dimensionality of substrate for VA is increasingly recognized, ICE is invaluable in identifying scar topography in the endocardial, midmyocardial, and epicardial layers. ICE assists in identifying endocavitary structures that are a common source of VA in idiopathic and structural heart disease. Furthermore, as substrate imaging of the right ventricle has not been optimized with other imaging modalities, ICE offers a unique opportunity to visualize substrate in this chamber. Real-time substrate identification can be particularly useful where there are contraindications to use of other imaging modalities or the images are obscured by artefact in the presence of cardiac device leads. In this review we provide a step-by-step guide in the techniques used to image ventricular arrhythmia substrate with ICE. We also discuss the benefits and limitations of this technique in comparison to other imaging modalities.

Snare and track (SNACK) technique: a novel approach for successful placement of an intracardiac echocardiogram catheter in the left atrium: a case report.

Background: Placing an intracardiac echocardiogram (ICE) catheter in the left atrium allows for excellent visualization of the left atrial appendage to guide left atrial (LA) appendage occlusion (LAAO). Nonetheless, it requires a separate septal puncture or a unique set of skills to navigate the ICE through a previously prepared septal puncture, which can be challenging. Case summary: This report describes a novel method to insert an ICE in the left atrium through a single septal puncture utilizing a snare technique. A 76-year-old male underwent LAAO by ICE guidance. After obtaining a standard atrial septal puncture, we were unable to advance the ICE into the left atrium. Therefore, we used a loop snare to grasp the ICE catheter-tip in the right atrium and direct it into the left atrium via the prepared septal puncture by tracking a pigtail wire that we routinely place as part of the procedure. Afterward, the left atrial appendage was successfully occluded with a Watchman device (Boston Scientific, Galway, Ireland), and the patient was discharged home without complications. Discussion: The described technique could be a helpful tool for ICE placement to the left atrium in a controlled fashion, especially when challenging anatomy is encountered.

Intracardiac echocardiography from coronary sinus.

Intracardiac echocardiography (ICE) has become an essential tool and is an integral part of percutaneous interventional and electrophysiology (EP) procedures. Intracardiac echocardiography offers real-time, high-quality, near-field evaluation of cardiac anatomy. Standard ICE imaging includes placing the catheter in the right atrium (RA), right ventricle (RV), or left atrium (LA, via the transeptal approach). Coronary sinus echocardiography (CSE) is another alternative, where the ICE catheter is positioned in the coronary sinus (CS). This approach offers better catheter stability and allows operators to visualize cardiac structure with particularly excellent views of the LA, LAA, left ventricle (LV), and mitral annulus. Additionally, CSE is an attractive alternative in cases with unfavorable interatrial septum or fossa ovalis anatomical features that could lead to difficulty advancing ICE catheter in left atrium. In this article focusing on CSE, we provide illustration-based guidance to help operators identify critical cardiac structures from CSE.

Safety, Efficacy, and Cost-Effectiveness of Same-Day Discharge for Left Atrial Appendage Occlusion.

BACKGROUND: Percutaneous left atrial appendage occlusion (LAAO) with the Watchman device is FDA approved for stroke prevention in patients with nonvalvular atrial fibrillation who have an appropriate indication. During the COVID-19 pandemic, a same-day discharge protocol (SDDP) was employed to improve resource utilization, relieve hospital occupation, and reduce the possible risk of in-hospital virus transmission. OBJECTIVES: We sought to analyze the safety, feasibility, and cost effectiveness for SDDP in patients receiving LAAO. METHODS: A prospective analysis of 142 consecutive patients, 119 treated prior to SDDP and 23 who underwent SDDP following LAAO with cardiac computed tomography angiography (CTA)-guided pre-procedural planning and intracardiac echocardiogram (ICE). Procedures were performed in a single, large academic hospital in the United States. In-hospital and 45-day procedural success, adverse events, length of procedure, and length-of-stay were evaluated. RESULTS: Baseline patient characteristics including mean CHA2DS2VASc scores and mean HAS-BLED scores were similar in both groups. All procedures were successful. There was no significant difference in rates of procedural complications or in-hospital adverse events. The mean procedure time in the SDDP group was 11 minutes longer than in the conventional group (62.1 ± 5.9 vs 51.1 ± 21; P=.01). Outcomes at 45-day follow-up were similar. SDDP was associated with a reduced length of stay compared with conventional strategy and a 15% reduction in total costs. CONCLUSIONS: Same-day discharge strategy for LAAO appears safe, feasible and could become the new standard approach for LAAO. A protocol including CTA pre-procedural planning, ICE-guided deployment and conscious sedation reduces hospital occupation and lowers costs.

Left Atrial Appendage Occlusion Using Cardiac CT Angiography and Intracardiac Echocardiography: A Prospective, Single-Center Study.

OBJECTIVES: We reviewed the periprocedural events, accuracy of device selection, and outcomes of a series of patients receiving percutaneous left atrial appendage occlusion (LAAO) with cardiac computed tomography angiography (CTA)-guided preprocedural planning and intracardiac echocardiography (ICE)-guided device deployment. BACKGROUND: Percutaneous LAAO with the Watchman device (Boston Scientific) is approved by the United States Food and Drug Administration for stroke prevention in patients with non-valvular atrial fibrillation with a demonstrated contraindication to oral anticoagulation. Cardiac CTA preprocedural planning with utilization of an ICE-guided deployment may be associated with favorable outcomes. METHODS: A prospective analysis of 71 non-consecutive patients who underwent LAAO over an 18-month period with cardiac CTA-guided preprocedural planning and ICE was conducted. Procedures were performed in a single large, academic hospital in the United States. Procedural success, correlation of CTA preprocedural device sizing with final device size utilization, adverse events, length of procedure, and length of stay were evaluated. RESULTS: Preprocedural cardiac CTA-guided device sizing was consistent with the final deployed device in 69 patients (97.2%) evaluated in this case series. Procedure success rate was 100%. All implants were performed using Watchman devices, 45 (63.4%) with the original 2.5 platform and 26 (36.6%) with the Watchman FLX platform. All patients were treated with conscious sedation and the mean length of stay was 1.45 ± 0.72 days. Only 2 adverse events occurred and both resolved. CONCLUSIONS: Cardiac CTA-guided preprocedural planning resulted in accurate device sizing in this patient sample and may be used in conjunction with ICE and conscious sedation for a same-day discharge strategy in select patients.

Left Atrial Appendage Closure in a Patient With a Patent Foramen Ovale Septal Occluder Device.

Left atrial appendage closure (LAAC) has evolved as a safe alternative to oral anticoagulation therapy for stroke prophylaxis. However, the presence of a patent foramen ovale (PFO) occluder device is considered a relative contraindication. Here we report a successful case of LAAC in the presence of a PFO occluder device. (Level of Difficulty: Beginner.).

Permanent left bundle branch area pacing utilizing intracardiac echocardiogram.

BACKGROUND: Recently, left bundle branch area pacing (LBBAP) has been shown to be feasible. However, the right ventricular (RV) implantation site for LBBAP remains elusive. We believe that the RV implantation site should be located at the posteromedial basal septum, and in this paper, we propose a new method to help guide lead implantation. The aim of this study is to demonstrate the feasibility of the proposed method. METHODS: The RV implantation site was positioned by a combination of a nine-grid system on fluoroscopy and the use of intracardiac echocardiogram (ICE) and then verified by ICE. RESULTS: Fifteen patients were enrolled for LBBAP using our method. The acute success rate was 86.7% (13/15), which demonstrated that our method is useful for assisting with lead implantation. According to ICE, the distance between the implantation site and apex (the front) and the distance between the implantation site and tricuspid annulus (the back) were 44.9 ± 10.7 and 33.2 ± 10.4 mm, respectively, and the ratio of the front and the back was 1.57 ± 0.80. The distance between the implantation site and the front junction point of the left-right ventricle (the upper) and the distance between the implantation site and the back junction point (the lower) were 33.4 ± 10.6 and 24.5 ± 10.2 mm, respectively. The ratio of the upper to the lower was 1.76 ± 1.36. These results suggest that the implantation site was at the posteromedial basal septum. The width of the QRS duration increased from 110.4 ± 33.1 ms at baseline to 114.1 ± 16.1 ms post LBBAP (P > 0.05). The operation time was 133 ± 32.9 min. The time of X-ray fluoroscopy was 21.2 ± 5.9 min. The mean time for lead positioning during LBBAP was 33.8 ± 16.6 min. During a follow-up of 3 months, the LBB capture threshold remained stable in 12 patients, except for one patient who had an increase in the LBB capture threshold to 3.0 v/0.4 ms. CONCLUSIONS: Our preliminary results indicate that the posteromedial basal septum could be seen as the implantation site for LBBAP. As a technique for LBBAP, ICE is a useful method for assisting with lead implantation. It is feasible and safe to use a nine-grid system combined with ICE for LBBAP.

From 100 to 0: Endocardial Radiofrequency Ablation of Septal Hypertrophy for Management of Hypertrophic Cardiomyopathy.

Septal reduction techniques can reduce morbidity and mortality in patients with hypertrophic cardiomyopathy. In a patient with hypertrophic cardiomyopathy who was a poor candidate for surgical myectomy and alcohol septal ablation, endocardial radiofrequency ablation of septal hypertrophy provided durable reduction in left ventricular outflow tract gradients and symptomatic improvement. (Level of Difficulty: Intermediate.).

A comparison of methods to determine patent foramen ovale size.

BACKGROUND: Patent foramen ovale (PFO) is implicated in the pathogenesis of clinical conditions such as cryptogenic stroke and migraine with aura. This study evaluated the challenges of sizing a PFO with different contemporary imaging modalities and assessed the relationship between PFO size and severity of the right-to-left shunt (RLS). METHODS: Patients who were referred to interventional cardiology with the diagnosis of a PFO and had undergone intra-procedural balloon sizing (n = 147), transesophageal echocardiogram (TEE) imaging (n = 67), or intracardiac echocardiogram (ICE) imaging (n = 73) at the time of workup were included in this study. TEE and ICE were used to obtain PFO length and height during normal respiration. A sizing balloon was used to obtain PFO width and height after the septum primum was opened with balloon inflation. RESULTS: The mean PFO length measured by TEE and ICE differed significantly (n = 27, 13.0 ± 4.1 vs. 9.9 ± 3.2 mm, p = .001). The mean PFO height measured by TEE and ICE (n = 27, 1.4 ± 0.6 vs. 1.7 ± 0.6 mm, p = .04), TEE and sizing balloon (n = 56, 1.5 ± 1.2 vs. 10.5 ± 4.2 mm, p < .0001), and ICE and sizing balloon (n = 66, 1.7 ± 0.7 vs. 9.1 ± 3.7 mm, p < .0001) also differed significantly. A poor correlation existed between anatomic PFO length or height and functional Spencer TCD grade RLS flow with Valsalva, irrespective of the imaging modality used. CONCLUSIONS: The determination of a PFO size is dependent on the imaging modality used. Sizing balloon demonstrates a larger width or height than ultrasound imaging methods, such as TEE and ICE, because a PFO remains closed most of the time, leading the echocardiogram to underestimate the potential PFO size. Additionally, PFO length and height correlate poorly with the functional RLS grade. These findings imply that ultrasound-based size characterization should not be used to determine whether a PFO should be closed.

The impact of the CartoSound® image directly acquired from the left atrium for integration in atrial fibrillation ablation.

PURPOSE: Intracardiac echocardiographic (ICE) imaging might be useful for integrating three-dimensional computed tomographic (CT) images for left atrial (LA) catheter navigation during atrial fibrillation (AF) ablation. However, the optimal CT image integration method using ICE has not been established. METHODS: This study included 52 AF patients who underwent successful circumferential pulmonary vein isolation (CPVI). In all patients, CT image integration was performed after the CPVI with the following two methods: (1) using ICE images of the LA derived from the right atrium and right ventricular outflow tract (RA-merge) and (2) using ICE images of the LA directly derived from the LA added to the image for the RA-merge (LA-merge). The accuracy of these two methods was assessed by the distances between the integrated CT image and ICE image (ICE-to-CT distance), and between the CT image and actual ablated sites for the CPVI (CT-to-ABL distance). RESULTS: The mean ICE-to-CT distance was comparable between the two methods (RA-merge = 1.6 ± 0.5 mm, LA-merge = 1.7 ± 0.4 mm; p = 0.33). However, the mean CT-to-ABL distance was shorter for the LA-merge (2.1 ± 0.6 mm) than RA-merge (2.5 ± 0.8 mm; p < 0.01). The LA, especially the left-sided PVs and LA roof, was more sharply delineated by direct LA imaging, and whereas the greatest CT-to-ABL distance was observed at the roof portion of the left superior PV (3.7 ± 2.8 mm) after the RA-merge, it improved to 2.6 ± 1.9 mm after the LA-merge (p < 0.01). CONCLUSIONS: Additional ICE images of the LA directly acquired from the LA might lead to a greater accuracy of the CT image integration for the CVPI.