Ventricular Intramyocardial Navigation for Tachycardia Ablation Guided by Electrograms (VINTAGE): Deep Ablation in Inaccessible Targets.

BACKGROUND: Deep intramural ventricular tachycardia substrate targets are difficult to access, map, and ablate from endocardial and epicardial surfaces, resulting in high recurrence rates. OBJECTIVES: In this study, the authors introduce a novel approach called ventricular intramyocardial navigation for tachycardia ablation guided by electrograms (VINTAGE) to access and ablate anatomically challenging ventricular tachycardia from within the myocardium. METHODS: Guidewire/microcatheter combinations were navigated deep throughout the extravascular myocardium, accessed directly from the right ventricle cavity, in Yorkshire swine (6 naive, 1 infarcted). Devices were steered to various intramyocardial targets including the left ventricle summit, guided by fluoroscopy, unipolar electrograms, and/or electroanatomic mapping. Radiofrequency ablations were performed to characterize ablation parameters and reproducibility. Intramyocardial saline irrigation began 1 minute before ablation and continued throughout. Lesions were analyzed on cardiac magnetic resonance and necropsy. RESULTS: VINTAGE was feasible in all animals within naive and infarcted myocardium. Forty-three lesions were created, using various guidewires and power settings. Forty-one (95%) lesions were detected on cardiac magnetic resonance and 38 (88%) on necropsy; all undetected lesions resulted from intentionally subtherapeutic ablation energy (10 W). Larger-diameter guidewires yielded larger size lesions. Lesion volumes on necropsy were significantly larger at 20 W than 10 W (178 mm3 [Q1-Q3: 104-382 mm3] vs 49 mm3 [Q1-Q3: 35-93 mm3]; P = 0.02). Higher power (30 W) did not create larger lesions. Median impedance dropped with preablation irrigation by 12 Ω (Q1-Q3: 8-17 Ω), followed by a further 15-Ω (Q1-Q3: 11-19 Ω) drop during ablation. Intramyocardial navigation, ablation, and irrigation were not associated with any complications. CONCLUSIONS: VINTAGE was safe and effective at creating intramural ablation lesions in targets traditionally considered inaccessible from the endocardium and epicardium, both naive and infarcted. Intramyocardial guidewire irrigation and ablation at 20 W creates reproducibly large intramural lesions.

Impact of Tricuspid Regurgitation on Outcomes After Transcatheter Mitral Valve Replacement.

Development of functional tricuspid regurgitation (TR) because of chronic mitral disease and subsequent heart failure is common. However, the effect of TR on clinical outcomes after transcatheter mitral valve replacement (TMVR) remains unclear. We aimed to evaluate the impact of baseline TR on outcomes after TMVR. This was a single-center, retrospective analysis of patients who received valve-in-valve or valve-in-ring TMVR between 2012 and 2022. Patients were categorized into none/mild TR and moderate/severe TR based on baseline echocardiography. The primary outcome was 3 years all-cause death and the secondary outcomes were in-hospital events. Of the 135 patients who underwent TMVR, 64 (47%) exhibited none/mild TR at baseline, whereas 71 (53%) demonstrated moderate/severe TR. There were no significant differences in in-hospital events between the groups. At 3 years, the moderate/severe TR group exhibited a significantly increased risk of all-cause death (adjusted hazard ratio 3.37, 95% confidence interval 1.35 to 8.41, p = 0.009). When patients with baseline moderate/severe TR were stratified by echocardiography at 30 days into improved (36%) and nonimproved (64%) TR groups, although limited by small sample size, there was no significant difference in 3-year all-cause mortality (p = 0.48). In conclusion, this study investigating the impact of baseline TR on clinical outcomes revealed that moderate/severe TR is prevalent in those who underwent TMVR and is an independent predictor of 3-year all-cause mortality. Earlier mitral valve intervention before the development of significant TR may play a pivotal role in improving outcomes after TMVR.

Transcatheter Myotomy to Reduce Left Ventricular Outflow Obstruction.

BACKGROUND: Left ventricular outflow tract (LVOT) obstruction is a source of morbidity in hypertrophic cardiomyopathy (HCM) and a life-threatening complication of transcatheter mitral valve replacement (TMVR) and transcatheter aortic valve replacement (TAVR). Available surgical and transcatheter approaches are limited by high surgical risk, unsuitable septal perforators, and heart block requiring permanent pacemakers. OBJECTIVES: The authors report the initial experience of a novel transcatheter electrosurgical procedure developed to mimic surgical myotomy. METHODS: We used septal scoring along midline endocardium (SESAME) to treat patients, on a compassionate basis, with symptomatic LVOT obstruction or to create space to facilitate TMVR or TAVR. RESULTS: In this single-center retrospective study between 2021 and 2023, 76 patients underwent SESAME. In total, 11 (14%) had classic HCM, and the remainder underwent SESAME to facilitate TMVR or TAVR. All had technically successful SESAME myocardial laceration. Measures to predict post-TMVR LVOT significantly improved (neo-LVOT 42 mm2 [Q1-Q3: 7-117 mm2] to 170 mm2 [Q1-Q3: 95-265 mm2]; P < 0.001; skirt-neo-LVOT 169 mm2 [Q1-Q3: 153-193 mm2] to 214 mm2 [Q1-Q3: 180-262 mm2]; P < 0.001). Among patients with HCM, SESAME significantly decreased invasive LVOT gradients (resting: 54 mm Hg [Q1-Q3: 40-70 mm Hg] to 29 mm Hg [Q1-Q3: 12-36 mm Hg]; P = 0.023; provoked 146 mm Hg [Q1-Q3: 100-180 mm Hg] to 85 mm Hg [Q1-Q3: 40-120 mm Hg]; P = 0.076). A total of 74 (97.4%) survived the procedure. Five experienced 3 of 76 (3.9%) iatrogenic ventricular septal defects that did not require repair and 3 of 76 (3.9%) ventricular free wall perforations. Neither occurred in patients treated for HCM. Permanent pacemakers were required in 4 of 76 (5.3%), including 2 after concomitant TAVR. Lacerations were stable and did not propagate after SESAME (remaining septum: 5.9 ± 3.3 mm to 6.1 ± 3.2 mm; P = 0.8). CONCLUSIONS: With further experience, SESAME may benefit patients requiring septal reduction therapy for obstructive hypertrophic cardiomyopathy as well as those with LVOT obstruction after heart valve replacement, and/or can help facilitate transcatheter valve implantation.

TABERNACL: Temporary Hemodynamic Stabilization In Vivo.

BACKGROUND: Acute aortic regurgitation is life-threatening with few nonsurgical options for immediate stabilization. We propose Trans-Aortic Balloon to Ease Regurgitation Applying Counter-Pulsation (TABERNACL), a simple, on-table temporary valve using commercially available equipment to temporize acute severe aortic regurgitation. METHODS: We hypothesize that an appropriately sized commercial balloon dilatation catheter-straddling the aortic annulus and connected to a counterpulsation console-can serve as a temporizing valve to restore hemodynamic stability in acute aortic regurgitation. We performed benchtop testing of valvuloplasty, angioplasty, and sizing balloons as counterpulsation balloons. TABERNACL was assessed in vivo in a porcine model of acute aortic regurgitation (n=8). We also tested a static undersized, continuously inflated transvalvular balloon as a spacer intended physically to obstruct the regurgitant orifice. RESULTS: Benchtop testing identified that Tyshak II and PTS sizing (NuMed Braun) balloon catheters performed adequately as temporary valves (ie, complete inflation and deflation with each cycle) and resisted fatigue, in contrast to others. When TABERNACL was used in the acute severe regurgitation animals, there was immediate hemodynamic improvement, with a significant 35% increase in diastolic aortic pressure by 16 mm Hg ([95% CI, 7-25] P=0.0056), 34% reduction in left ventricular end-diastolic pressure by -7 mm Hg ([95% CI, -10 to -5] P=0.0006), improvement in the aortic diastolic index by 0.28 ([95% CI, 0.18-0.39] P=0.0009), and reversal of electrocardiographic myocardial ischemia. As an alternative, static balloon inflation across the aortic valve stabilized regurgitation hemodynamics at the expense of a new aortic gradient and caused excessive ectopy from balloon movement in the left ventricular outflow tract. CONCLUSIONS: TABERNACL improves hemodynamics and reduces coronary ischemia by electrocardiography in animals with acute severe aortic regurgitation. TABERNACL valves obstruct the diastolic regurgitant orifice without systolic obstruction. This may prove a lifesaving bridge to definitive valve replacement therapy.

Left Ventricular Outflow Tract Modification for Transcatheter Mitral Valve Replacement.

Left ventricular outflow tract (LVOT) obstruction is a life-threatening complication of transcatheter mitral valve replacement. In-depth analysis of pre-procedural computed tomography enables accurate prediction of this risk. Several techniques for LVOT modification, including Laceration of the Anterior Mitral leaflet to Prevent Outflow ObtructioN, preemptive alcohol septal ablation, preemptive radiofrequency ablation, and Septal Scoring Along the Midline Endocardium, have been described as effective strategies to mitigate this risk. This review aims to explore the indications, procedural steps, and outcomes associated with these LVOT modification techniques.

Transcatheter Paravalvular Leak Closure With Covered Stent Tract and Vascular Plug: Tootsie Roll Technique.

BACKGROUND: Transcatheter closure of transcatheter heart valve (THV)-related paravalvular leak (PVL) is associated with a high failure rate with available devices due to the complex interaction of THV and aortic/mitral annulus. OBJECTIVES: This study reports on novel transcatheter techniques to treat PVL after THV. METHODS: The authors describe consecutive patients who underwent PVL closure after transcatheter aortic valve replacement (TAVR) or transcatheter mitral valve replacement (TMVR). A covered self-expanding stent (Viabahn) was deployed in the defect to create a seal between the THV and annulus. A vascular plug (Amplatzer Vascular Plug 2 [AVP2] or AVP4) was then deployed inside the covered stent to obliterate PVL. RESULTS: Eight patients with THV-related PVL were treated using this method (aortic [3 SAPIEN, 1 Evolut], mitral [2 SAPIEN-in-MAC (mitral annular calcification), 2 M3 TMVR). Various combinations of stents and plugs were used (5 mm × 2.5 cm Viabahn + 6 mm AVP4 [n = 2], 8 mm × 2.5 cm Viabahn + 10 mm AVP2 [n = 5], and 10 mm × 5.0 cm Viabahn + 12 mm AVP2 [n = 1]). All had technical success with immediate elimination of target PVL, without in-hospital complications. None had signs of postprocedure hemolysis. All patients were discharged alive (median 3.5 days [Q1-Q3: 1.0-4.8 days]). No residual PVL was seen at discharge, except for 1 patient with mild regurgitation due to another untreated PVL location. One patient died before 30 days due to complication of valve-in-MAC TMVR. In remaining patients, none had recurrence of PVL at 30 days. Symptoms decreased to NYHA functional class I/II in 6 patients. NYHA functional class III symptoms remained in 1 patient with mitral regurgitation awaiting subsequent valve replacement procedure. CONCLUSIONS: The technique of sequential deployment of a covered stent and vascular plug may effectively treat THV-related PVL.

Effect of Ascending Aortic Curvature on Flow in the Sinus and Neo-sinus Following TAVR: A Patient-Specific Study.

Patient-specific aortic geometry and its influence on the flow in the vicinity of Transcatheter Aortic Valve (TAV) has been highlighted in numerous studies using both in silico and in vitro experiments. However, there has not yet been a detailed Particle Image Velocimetry (PIV) experiment conducted to quantify the relationship between the geometry, flow downstream of TAV, and the flow in the sinus and the neo-sinus. We tested six different patient-specific aorta models with a 26-mm SAPIEN 3 valve (Edwards Lifesciences, Irvine, CA, USA) in a left heart simulator with coronary flow. Velocities in all three cusps and circulation downstream of TAV were computed to evaluate the influence of the ascending aorta curvature on the flow field. The in vitro analysis showed that the patient-specific aortic curvature had positive correlation to the circulation in the ascending aorta (p = 0.036) and circulation had negative correlation to the particle washout time in the cusps (p = 0.011). These results showed that distinct vortical flow patterns in the ascending aorta as the main jet impinges on the aortic wall causes a recirculation region that facilitates the flow back into the sinus and the neo-sinus, thus reducing the risk of flow stagnation and washout time.

Hybrid Closure of Postinfarction Apical Ventricular Septal Defect Using Septal Occluder Device and Right Ventricular Free Wall: The Apical BASSINET Concept.

BACKGROUND: Postinfarction ventricular septal defect (VSD) is a catastrophic complication of myocardial infarction. Surgical repair still has poor outcomes. This report describes clinical outcomes after a novel hybrid transcatheter/surgical repair in patients with apical VSD. METHODS: Seven patients with postmyocardial infarction apical VSD underwent hybrid transcatheter repair via subxiphoid surgical access. A transcatheter occluder (Amplatzer Septal Occluder) with a trailing premounted suture was deployed through the right ventricular wall and through the ventricular septum into the left ventricular apex. The trailing suture was used to connect an anchor external to the right ventricular wall. Tension on the suture then collapses the right ventricular free wall against the septum and left ventricular occluder, thereby obliterating the VSD. Outcomes were compared with 9 patients who underwent surgical repair using either patch or primary suture closure. RESULTS: All patients had significant left-to-right shunt (Qp:Qs 2.5:1; interquartile range [IQR, 2.1-2.6] hybrid repair versus 2.0:1 [IQR, 2.0-2.5] surgical repair), and elevated right ventricular systolic pressure (62 [IQR, 46-71] versus 49 [IQR, 43-54] mm Hg, respectively). All had severely depressed stroke volume index (22 versus 21 mL/m2) with ≈45% in each group requiring mechanical support preprocedurally. The procedure was done 15 (IQR, 10-50) versus 24 (IQR, 10-134) days postmyocardial infarction, respectively. Both groups of patients underwent repair with technical success and without intraprocedural death. One patient in the hybrid group and 4 in the surgical group developed multiorgan failure. The hybrid group had a higher survival at discharge (86% versus 56%) and at 30 days (71% versus 56%), but similar at 1 year (57% versus 56%). During follow-up, 1 patient in each group required reintervention for residual VSD (hybrid: 9 months versus surgical: 5 days). CONCLUSIONS: Early intervention with a hybrid transcatheter/surgical repair may be a viable alternative to traditional surgery for postinfarction apical VSD.

Prospective validation of a risk score to predict pacemaker implantation after transcatheter aortic valve replacement.

INTRODUCTION: The need for pacemaker is a common complication after transcatheter aortic valve replacement (TAVR). We previously described the Emory Risk Score (ERS) to predict the need for new pacemaker implant (PPM) after TAVR. Metrics included in the score are a history of syncope, pre-existing RBBB, QRS duration ≥140 ms, and prosthesis oversizing ≥16%. To prospectively validate the previously described risk score. METHODS: We prospectively evaluated all patients without pre-existing pacemakers, ICD, or pre-existing indications for pacing undergoing TAVR with the Edwards SAPIEN 3 prosthesis at our institution from March 2019 to December 2020 (n = 661). Patients were scored prospectively; however, results were blinded from clinical decision-making. The primary endpoint was PPM at 30 days after TAVR. Performance of the ERS was evaluated using logistic regression, a calibration curve to prior performance, and receiver operating characteristic (ROC) analysis. RESULTS: A total of 48 patients (7.3%) had PPM after TAVR. A higher ERS predicted an increased likelihood of PPM (OR 2.61, 95% CI: 2.05-3.25 per point, p < 0.001). There was good correlation between observed and expected values on the calibration curve (slope = 1.04, calibration at large = 0.001). The area under the ROC curve was 0.81 (95% CI [0.74-0.88], p < 0.001). CONCLUSIONS: The ERS prospectively predicted the need for PPM in a serial, real-world cohort of patients undergoing TAVR with a balloon-expandable prosthesis, confirming findings previously described in retrospective cohorts. Notably, the prospective performance of the score was comparable with that of the initial cohorts. The risk score could serve as a framework for preprocedural risk stratification for PPM after TAVR.

Physician-Modified Endograft-Facilitated Transcatheter Pulmonary Valve Replacement in Large Right Ventricular Outflow Tract.

BACKGROUND: Transcatheter pulmonary valve replacement (TPVR) in patients with a congenital or acquired abnormality resulting in enlarged right ventricular outflow tract (RVOT) is challenging and may preclude treatment with dedicated devices. We describe a technique using a physician-modified endograft to facilitate TPVR. METHODS: Six patients underwent physician-modified endograft-facilitated TPVR for severe symptomatic pulmonary insufficiency with enlarged RVOT. The fenestration was created in a commercially available endograft before implantation, which was then deployed from the dominant branch pulmonary artery into the RVOT, with the fenestration aligned with the ostium of the nondominant pulmonary artery. A covered stent was placed through the fenestration into the nondominant branch pulmonary artery, and a transcatheter heart valve was deployed within the endograft at the level of the original pulmonary valve. RESULTS: Four patients had tetralogy of Fallot, 1 had pulmonary atresia, and 1 had rheumatic valve disease. The RVOT/main pulmonary artery was severely enlarged (diameter, 44.2 [43.5-50.6] mm). All patients had reduced right ventricular (RV) function and dilated RVs (RV end-diastolic volume, 314 [235-316] mL). Successful endograft, covered stent, and transcatheter heart valve deployment were achieved in all cases without stent/valve embolization, vascular complications, or bleeding complications. At 30 days, 1 patient had mild pulmonary insufficiency, while others had none. The RV size measured by echocardiography was significantly reduced after TPVR (RV area, 34.4 [baseline] versus 29.0 [pre-discharge] versus 25.3 [30 days] cm2; P=0.03). During median follow-up of 221.5 (range, 29-652) days, there were no deaths or need for pulmonary valve reintervention. One patient developed severe tricuspid regurgitation due to entrapment of the anterior tricuspid leaflet by the endograft. The patient underwent successful tricuspid replacement and resection of the offending endograft with preservation of the pulmonary valve prosthesis. CONCLUSIONS: Simple fenestration of an off-the-shelf endograft and associated covered stent placement through the fenestration allows TPVR for patients with dysfunctional native or patch-repaired pulmonary valves and RVOT enlargement.

EDEN (Electrocardiographic Radial Depth Navigation): A Novel Approach to Navigate Inside Heart Muscle.

BACKGROUND: Intramyocardial guidewire navigation is a novel technique that allows free transcatheter movement within ventricular muscle. Guidewire radial depth, between endocardial and epicardial surfaces, is ambiguous by x-ray and echocardiography. OBJECTIVES: The aim of this study was to develop a simple tool, EDEN (Electrocardiographic Radial Depth Navigation), to indicate radial depth during intramyocardial guidewire navigation. Combined with routine imaging, EDEN facilitates a new family of intramyocardial catheter procedures to slice, reshape, pace, and ablate the heart. METHODS: We mapped intramyocardial electrograms of left and right ventricular walls and septum during open- and closed-chest swine procedures (N = 53), including MIRTH (Myocardial Intramural Remodeling by Transvenous Tether) ventriculoplasty. We identified radial depth-dependent features on unipolar electrograms. We developed a machine learning-based classifier to indicate categorical position, and modeled the findings in silico to test understanding of the physiology. RESULTS: EDEN signatures distinguished 5 depth zones throughout left and right ventricular free walls and interventricular septum. Relative ST-segment elevation magnitude best discriminated position and was maximum (40.1 ± 6.5 mV) in the midmyocardium. Subendocardial positions exhibited dominant Q waves with lower-amplitude ST segments (16.8 ± 5.8 mV), whereas subepicardial positions exhibited dominant R waves with lower-amplitude ST segments (15.7 ± 4.8 mV). EDEN was unaffected by pacing-induced left bundle branch block. ST-segment elevation declined over minutes and reappeared after submillimeter guidewire manipulation. Modeling recapitulated EDEN features. The machine learning-based classifier was 97% accurate. EDEN successfully guided MIRTH ventriculoplasty. CONCLUSIONS: EDEN provides a simple and reproducible real-time reflection of categorical guidewire-tip radial depth during intramyocardial guidewire navigation. Used in tandem with x-ray, EDEN enables novel, transcatheter, intramyocardial therapies such as MIRTH, SESAME (Septal Surfing Along Midline Endocardium), and cerclage ventriculoplasty.

Transcatheter Mitral Valve Replacement in Failed Bioprosthetic Valve, Ring, and Mitral Annular Calcification Associated Mitral Valve Disease Using Balloon Expandable Transcatheter Heart Valve.

Transcatheter mitral valve replacement (TMVR) using the SAPIEN platform has been performed in failed bioprosthetic valves (valve-in-valve), surgical annuloplasty rings (valve-in-ring), and native valves with mitral annular calcification (MAC) (valve-in-MAC). Experience over the past decade has identified important challenges and solutions to improve clinical outcomes. In this review, we discuss the indication, trend in utilization, unique challenges, procedural planning, and clinical outcomes of valve-in-valve, valve-in-ring, and valve-in-MAC TMVR.

Transcaval Access and Closure Best Practices.

Transcaval aortic access is a versatile electrosurgical technique for large-bore arterial access through the wall of the abdominal aorta from the adjoining inferior vena cava. Although counterintuitive, its relative safety derives from the recognition that interstitial hydraulic pressure exceeds venous pressure, so arterial bleeding harmlessly decompresses into the nearby caval venous hole. Transcaval access has been performed in thousands of patients for transcatheter aortic valve replacement and endovascular thoracic aneurysm repair and to avoid limb ischemia in percutaneous mechanical circulatory support. Transcaval access may have value compared with transaxillary or subclavian access and with surgical transcarotid access when standard transfemoral access is not optimal. The dissemination of transcaval access and closure techniques has been hampered by the unavailability of commercially marketed devices. This state-of-the-art review details exemplary transcaval technique, patient selection, computed tomographic planning, step-by-step access and closure, management of complications, and procedural troubleshooting in special situations. These contemporary best practices can help operators gain or maintain proficiency.

Coronary Obstruction From TAVR in Native Aortic Stenosis: Development and Validation of Multivariate Prediction Model.

BACKGROUND: Transcatheter aortic valve replacement (TAVR)-related coronary artery obstruction prediction remains unsatisfactory despite high mortality and novel preventive therapies. OBJECTIVES: This study sought to develop a predictive model for TAVR-related coronary obstruction in native aortic stenosis. METHODS: Preprocedure computed tomography and fluoroscopy images of patients in whom TAVR caused coronary artery obstruction were collected. Central laboratories made measurements, which were compared with unobstructed patients from a single-center database. A multivariate model was developed and validated against a 1:1 propensity-matched subselection of the unobstructed cohort. RESULTS: Sixty patients with angiographically confirmed coronary obstruction and 1,381 without obstruction were included. In-hospital death was higher in the obstruction cohort (26.7% vs 0.7%; P < 0.001). Annular area and perimeter, coronary height, sinus width, and sinotubular junction height and width were all significantly smaller in the obstructed cohort. Obstruction was most common on the left side (78.3%) and at the level of the coronary artery ostium (92.1%). Coronary artery height and sinus width, but not annulus area, were significant risk factors for obstruction by logistic regression but performed poorly in predicting obstruction. The new multivariate model (coronary obstruction IF cusp height > coronary height, AND virtual valve-to-coronary distance ≤4 mm OR culprit leaflet calcium volume >600 mm3) performed well, with an area under the curve of 0.93 (sensitivity = 0.93, specificity = 0.84) for the left coronary artery and 0.94 (sensitivity = 0.92, specificity = 0.96) for the right. CONCLUSIONS: A novel computed tomography-based multivariate prediction model that can be implemented routinely in real-world practice predicted coronary artery obstruction from TAVR in native aortic stenosis.

Reshaping the Ventricle From Within: MIRTH (Myocardial Intramural Remodeling by Transvenous Tether) Ventriculoplasty in Swine.

MIRTH (Myocardial Intramural Remodeling by Transvenous Tether) is a transcatheter ventricular remodeling procedure. A transvenous tension element is placed within the walls of the beating left ventricle and shortened to narrow chamber dimensions. MIRTH uses 2 new techniques: controlled intramyocardial guidewire navigation and EDEN (Electrocardiographic Radial Depth Navigation). MIRTH caused a sustained reduction in chamber dimensions in healthy swine. Midventricular implants approximated papillary muscles. MIRTH shortening improved myocardial contractility in cardiomyopathy in a dose-dependent manner up to a threshold beyond which additional shortening reduced performance. MIRTH may help treat dilated cardiomyopathy. Clinical investigation is warranted.

Transcatheter Electrosurgery: A Narrative Review.

Transcatheter electrosurgery describes the ability to cut and traverse tissue, at a distance, without an open surgical field and is possible using either purpose-built or off-the-shelf devices. Tissue traversal requires focused delivery of radiofrequency energy to a guidewire tip. Initially employed to cross atretic pulmonary valves, tissue traversal has enabled transcaval aortic access, recanalization of arterial and venous occlusions, transseptal access, and many other techniques. To cut tissue, the selectively denuded inner curvature of a kinked guidewire (the Flying-V) or a single-loop snare is energized during traction. Adjunctive techniques may complement or enable contemporary transcatheter procedures, whereas myocardial slicing or excision of ectopic masses may offer definitive therapy. In this contemporary review we discuss the principles of transcatheter electrosurgery, and through exemplary clinical applications highlight the range of therapeutic options offered by this versatile family of procedures.

First Application of the LAMPOON Procedure to a Surgical Mitral Bioprosthesis.

A cardiogenic shock patient with a history of a surgical mitral valve replacement presented to the hospital with critical mitral stenosis with thickening of prosthetic valve leaflets and thrombus in left atrial appendage. We considered TMVR inside of the degenerated bioprosthetic valve. However, there were two concerns during TMVR based on multimodality imaging assessment: 1) LVOT obstruction due to the surgical bioprosthetic leaflet, 2) stroke due to left atrial appendage thrombus. We performed TMVR with LAMPOON (laceration of the anterior leaflet of the surgical valve to prevent left ventricular outflow tract obstruction) for the bioprosthesis using cerebral protection. While the LAMPOON procedure has developed to prevent LVOT obstruction by the native anterior mitral leaflet during transcatheter mitral valve-in-ring or valve-in-mitral annular calcification, this is the first case that illustrates its use for mitral valve-in-valve replacement.