Five-year follow-up after percutaneous pulmonary valve implantation using the Venus P-valve system for patients with pulmonary regurgitation and an enlarged native right ventricular outflow tract.

BACKGROUND: Percutaneous pulmonary valve implantation (PPVI) with the self-expandable Venus P-valve system is a promising treatment for patients with pulmonary regurgitation (PR) and a native right ventricular outflow tract (RVOT). However, limited data is available regarding its midterm outcomes. This study assessed the midterm clinical and echocardiographic outcomes following Venus P-valve implantation. METHODS: From 2013 to 2018, 55 patients with moderate or severe PR after surgical RVOT repair with a transannular or RVOT patch were consecutively enrolled from six hospitals in China. Five-year clinical and echocardiographic outcomes were collected and evaluated. The primary endpoint was a freedom from all-cause mortality and reintervention. RESULTS: At 5 years, the primary endpoint was met for 96% of patients, corresponding to a freedom from all-cause mortality of 96% (95% confidence interval [CI]: 86%-99%) and freedom from reintervention of 98% (95% CI: 87%-100%). Endocarditis was reported in five patients (four patients within 1 year and one patient at 5 years) following PPVI. Transpulmonary gradient and stent orifice diameter remained stable compared to at discharge (p＞0.05). No paravalvular leak was reported while only 1 patient gradually increased to moderate PR during follow-up. Significant improvement of RV diameter and LVEF (p＜0.001) sustained over the 5-year follow-up, in consistent with remarked improved New York Heart Association(NYHA) functional class (p＜0.001). CONCLUSION: The 5-year results of the China VenusP Study demonstrated the midterm benefits of Venus P-valve implantation in the management of patients with severe PR with an enlarged native RVOT by providing sustained symptomatic and hemodynamic improvement.

Finite element modeling with patient-specific geometry to assess clinical risks of percutaneous pulmonary valve implantation.

BACKGROUND: Percutaneous pulmonary valve implantation (PPVI) is a non-surgical treatment for right ventricular outflow tract (RVOT) dysfunction. During PPVI, a stented valve, delivered via catheter, replaces the dysfunctional pulmonary valve. Stent oversizing allows valve anchoring within the RVOT, but overexpansion can intrude on the surrounding structures. Potentially dangerous outcomes include aortic valve insufficiency (AVI) from aortic root (AR) distortion and myocardial ischemia from coronary artery (CA) compression. Currently, risks are evaluated via balloon angioplasty/sizing before stent deployment. Patient-specific finite element (FE) analysis frameworks can improve pre-procedural risk assessment, but current methods require hundreds of hours of high-performance computation. METHODS: We created a simplified method to simulate the procedure using patient-specific FE models for accurate, efficient pre-procedural PPVI (using balloon expandable valves) risk assessment. The methodology was tested by retrospectively evaluating the clinical outcome of 12 PPVI candidates. RESULTS: Of 12 patients (median age 14.5 years) with dysfunctional RVOT, 7 had native RVOT and 5 had RV-PA conduits. Seven patients had undergone successful RVOT stent/valve placement, three had significant AVI on balloon testing, one had left CA compression, and one had both AVI and left CA compression. A model-calculated change of more than 20% in lumen diameter of the AR or coronary arteries correctly predicted aortic valve sufficiency and/or CA compression in all the patients. CONCLUSION: Agreement between FE results and clinical outcomes is excellent. Additionally, these models run in 2-6 min on a desktop computer, demonstrating potential use of FE analysis for pre-procedural risk assessment of PPVI in a clinically relevant timeframe.

Flow pattern analysis of right ventricular outflow tract in repaired tetralogy of Fallot through 4D flow MRI.

Cardiac magnetic resonance imaging (CMR) often shows discrepancies between right ventricular outflow tract (RVOT) flow and left ventricular outflow tract flow in patients with late-stage repaired tetralogy of Fallot (rTOF), leading to potential errors in pulmonary regurgitation fraction (PRF) assessment. This study aimed to identify the conditions under which RVOT flow can be acutely evaluated using four-dimensional (4D) flow CMR. Twenty-seven consecutive patients with rTOF underwent both two-dimensional phase-contrast (2D PC) and 4D flow CMR between 2016 and 2018, excluding those with peripheral pulmonary artery stenosis, RVOT conduit replacement, unknown surgical method, and an aortic valve regurgitation greater than 20%. Seven healthy controls also underwent only 4D Flow CMR. All healthy controls and fifteen patients with rTOF showed laminar RVOT flow, while seven patients exhibited helical, and four patients exhibited vortical RVOT flow in 4D flow CMR visualization. Flow-volume concordance between the pulmonary artery and aortic flow was significantly lower in patients with rTOF and PRF > 40% in 2D PC CMR. This concordance rate in the suprapulmonary valve was high in both the TOF and control groups, comparing at five RVOT locations in 4D flow CMR. Regarding RVOT flow regurgitation in 4D flow, the whole bulk evaluation exhibited greater variation depending on the flow type compared to the whole pixel-wise evaluation. The study confirmed the flow volume at the upper section of the pulmonary valve as the most accurate correlate of aortic flow volume. Furthermore, the 4D flow CMR using the pixel-wise method demonstrated superior accuracy compared to the traditional bulk flow method.

Left Ventricular Outflow Tract Obstruction in Congenital Heart Disease: The Role of Cardiovascular Computed Tomography in Surgical Decision Making.

Patients with many forms of congenital heart disease (CHD) and hypertrophic cardiomyopathy undergo surgical intervention to relieve left ventricular outflow tract obstruction (LVOTO). Cardiovascular Computed Tomography (CCT) defines the complex pathway from the ventricle to the outflow tract and can be visualized in 2D, 3D, and 4D (3D in motion) to help define the mechanism and physiologic significance of obstruction. Advanced cardiac visualization may aid in surgical planning to relieve obstruction in the left ventricular outflow tract, aortic or neo-aortic valve and the supravalvular space. CCT scanner technology has advanced to achieve submillimeter, isotropic spatial resolution, temporal resolution as low as 66 msec allowing high-resolution imaging even at the fast heart rates and small cardiac structures of pediatric patients ECG gating techniques allow radiation exposure to be targeted to a minimal portion of the cardiac cycle for anatomic imaging, and pulse modulation allows cine imaging with a fraction of radiation given during most of the cardiac cycle, thus reducing radiation dose. Scanning is performed in a single heartbeat or breath hold, minimizing the need for anesthesia or sedation, for which CHD patents are highest risk for an adverse event. Examples of visualization of complex left ventricular outflow tract obstruction in the subaortic, valvar and supravalvular space will be highlighted, illustrating the novel applications of CCT in this patient subset.

Three-dimensional anatomic features of the mitral valve that predict systolic anterior motion occurring during dobutamine stress echocardiography.

BACKGROUND/AIM: Left ventricular outflow tract obstruction related to systolic anterior motion (SAM) of the mitral valve is a common complication of dobutamine stress echocardiography (DSE). However, the mechanisms underlying SAM have not been fully characterized. The objective of the present study was to use three-dimensional echocardiography to identify anatomic features of the mitral valve that predispose to SAM during DSE. METHODS: We retrospectively evaluated consecutive patients included prospectively in our database and who had undergone 3D echocardiography (including an assessment of the mitral valve) before DSE. Patients who had developed SAM during DSE (the SAM+ group) were matched 2:3 with patients who did not (the SAM- group). RESULTS: One hundred patients were included (mean age: 67 ± 10). Compared with SAM- patients (n = 60), SAM+ patients (n = 40) had a lower mitral annular area, a smaller perimeter, and a smaller diameter (p < .01 for all, except the anteroposterior diameter). The SAM+ group had also a narrower mitral-aortic angle (126 ± 12° vs. 139 ± 11° in the SAM- group; p < .01) and a higher posterior mitral leaflet length (1.4 ± .27 cm vs. 1.25 ± .29, respectively; p < .01). Furthermore, the mitral annulus was more spherical, more flexible, and more dynamic in SAM+ patients than in SAM- patients (p < .05 for all). In a multivariate analysis of anatomic variables, the mitral-aortic angle, the mitral annular area, and posterior leaflet length were independent predictors of SAM (p ≤ .01 for all). In a multivariate analysis of standard echo and hemodynamic variables, the presence of wall motion abnormalities at rest (p < .01) was an independent predictor of SAM. CONCLUSION: SAM during DSE is multifactorial. In addition to the pharmacologic effects of dobutamine on the myocardium, 3D echocardiographic features of the mitral valve (a smaller mitral annulus, a narrower mitral-aortic angle, and a longer posterior leaflet) appear to predispose to SAM.

Clinical Outcomes and Echocardiographic Predictors of Reintervention After Interrupted Aortic Arch Repair.

Left ventricular outflow tract obstruction (LVOTO) remains a significant complication after primary repair of interrupted aortic arch with ventricular septal defect (IAA-VSD). Clinical and echocardiographic predictors for LVOTO reoperation are controversial and procedures to prophylactically prevent future LVOTO are not reliable. However, it is important to identify the patients at risk for future LVOTO intervention after repair of IAA-VSD. Patients who underwent single-stage IAA-VSD repair at our center 2006-2021 were retrospectively reviewed, excluding patients with associated cardiac lesions. Two-dimensional measurements, LVOT gradients, and 4-chamber (4C) and short-axis (SAXM) strain were obtained from preoperative and predischarge echocardiograms. Univariate risk analysis for LVOTO reoperation was performed using unpaired t-test. Thirty patients were included with 21 (70%) IAA subtype B and mean weight at surgery 3.0 kg. Repair included aortic arch patch augmentation in 20 patients and subaortic obstruction intervention in three patients. Seven (23%) required reoperations for LVOTO. Patient characteristics were similar between patients who required LVOT reoperation and those who did not. Patch augmentation was not associated with LVOTO reintervention. Patients requiring reintervention had significantly smaller LVOT AP diameter preoperatively and at discharge, and higher LVOT velocity, smaller AV annular diameter, and ascending aortic diameter at discharge. There was an association between LVOT-indexed cross-sectional area (CSAcm2/BSAm2) ≤ 0.7 and reintervention. There was no significant difference in 4C or SAXM strain in patients requiring reintervention. LVOTO reoperation was not associated with preoperative clinical or surgical variables but was associated with smaller LVOT on preoperative echo and smaller LVOT, smaller AV annular diameter, and increased LVOT velocity at discharge.

Multimodal imaging diagnosis of left ventricular outflow tract obstruction due to abnormal papillary muscle insertion.

This article reports a case of LV outflow obstruction caused by abnormalities of the anterior leaflet connection of the mitral papillary muscle, aiming to highlight the importance of combined multimodal imaging in the differential diagnosis of the etiology of LV outflow obstruction.

[Left Ventricular Outflow Tract Obstruction After Transcatheter Aortic Valve Replacement due to Pannus Formation].

We experienced a case of surgical aortic valve re-replacement due to structural valve deterioration caused by pannus formation 4 years after transcatheter aortic valve replacement( TAVR). The patient underwent surgery because the mean transvalvular pressure gradient increased to 48 mmHg on echocardiography. Contrast-enhanced computed tomography (CT) was useful for predicting the site of adhesion to surrounding tissue preoperatively and exploring the presence of the pannus. Intraoperative findings showed the TAVR valve was covered with neointima except around the origins of the left and right coronary arteries and was firmly adhered to the surrounding tissues. As residual pannus was present in the subvalvular tissues, it was carefully removed. The explanted TAVR valve functioned well with good opening and closure. The postoperative course was uneventful. Pannus formation can result from mechanical stress. TAVR valves put significantly greater stress on the left ventricular outflow tract than surgical valves and may be more likely to cause pannus formation.

Imaging of left ventricular outflow tract obstruction in hypertrophic cardiomyopathy.

PURPOSE OF REVIEW: The current article reviews obstructive forms of hypertrophic cardiomyopathy and associated morphologic cardiac abnormalities. It focuses on echocardiographic imaging of the left ventricular (LV) outflow tract obstruction, its evaluation, prognostication, and differentiation from other conditions mimicking obstructive hypertrophic cardiomyopathy. RECENT FINDINGS: Symptomatic patients with LV outflow tract (LVOT) gradients at least 50 mmHg on maximally tolerated medical therapy are candidates for advanced therapies. Resting echocardiography may only identify 30% of patients with obstructive physiology. Provocative maneuvers are essential for symptomatic patients with hypertrophic cardiomyopathy (HCM). Exercise echocardiography is recommended if they fail to provoke a gradient. Although dynamic LV tract obstruction is seen with obstructive HCM, it is not specific to this condition and exists in other physiologic and pathophysiologic states. Careful clinical evaluation and imaging techniques aid in the differentiation of HCM from these conditions. SUMMARY: Imaging plays an integral role in the diagnosis, prognosis, and risk stratification of HCM patients. Newer imaging technologies, including 3D transthoracic echocardiography, 3D transesophageal, speckle-derived 2D strain, and cardiac MRI, allow for a better hemodynamic understanding of systolic anterior motion and LV tract obstruction. Evolving techniques, that is, artificial intelligence, will undoubtedly further increase diagnostic capabilities. Newer medical therapies are available with the hope that this will lead to better patient management.

A novel method of prosthetic leaflet modification to enable transcatheter mitral valve-in-valve replacement.

Left ventricular outflow tract (LVOT) obstruction from the displaced prosthetic anterior mitral leaflet is a life-threatening complication that can occur during valve-in-valve (ViV) transcatheter mitral valve replacement (TMVR). Laceration of the anterior mitral leaflet to prevent outflow obstruction is a well-established transcatheter technique to mitigate the risk of LVOT obstruction in high-risk anatomies. In this report, we present a novel transseptal technique of prosthetic leaflet modification to prevent LVOT obstruction during ViV TMVR.

Right ventricular outflow tract obstruction associated with neointimal tissue accumulation and distortion of the Harmony TPV25 stent frame: Potential mechanisms and treatment.

BACKGROUND: The Harmony TPV25 transcatheter pulmonary valve (Medtronic Inc.) is constructed with a self-expanding stent frame comprising six zigged nitinol wires sewn together and covered with knitted polyester fabric, with flared inflow and outflow ends and a porcine pericardial valve sutured to the central portion of the device. It was approved for treatment of pulmonary regurgitation after prior right ventricular outflow tract repair in 2021. Early outcomes of this procedure have been excellent, but little is known about valve durability or ultimate mechanisms of dysfunction. METHODS: We collected data on patients who underwent reintervention for TPV25 dysfunction and described findings related to distortion of the stent frame and tissue accumulation. RESULTS: We describe six patients who underwent valve-in-valve implant for TPV25 obstruction (peak catheterization gradient peak 28-73 mmHg) 10-28 months after implant. In all cases, there was tissue accumulation within the inflow and valve-housing segments of the device and deformation of the self-expanding valve frame characterized by variable circumferential narrowing at the junction between the valve housing and the inflow and outflow portions of the device, with additional geometric changes in all segments. All six patients underwent valve-in-valve implant that results in a final peak gradient ≤10 mmHg and no regurgitation. DISCUSSION: The occurrence of short-term Harmony TPV25 dysfunction in multiple patients with a similar appearance of frame distortion and tissue accumulation within the inflow and valve housing portions of the device suggests that this may be an important failure mechanism for this valve. Potential causes of the observed findings are discussed. It is possible to treat this mechanism of TPV25 dysfunction with valve-in-valve implant using balloon expandable transcatheter valves.

Preemptive alcohol septal ablation prior to transcatheter mitral valve replacement.

BACKGROUND: Alcohol septal ablation (ASA) has been shown to increase the neo-left ventricular outflow tract (LVOT) area before transcatheter mitral valve replacement (TMVR) but there is little literature on its success and use with dedicated devices. AIMS: To describe our experience with preemptive ASA to increase the predicted neo-LVOT area and its utility with both dedicated TMVR devices and balloon-expandable valves. METHODS: All patients who underwent ASA for TMVR candidacy in our center between May 2018 and October 2022 and had computed tomography (CT) scans done before and after ASA were included. Each CT was assessed for the minimum predicted neo-LVOT area at end-systole, using a virtual valve of the desired TMVR device for each patient. The primary outcome was an increase in the predicted neo-LVOT area after ASA that was deemed sufficient for safe implantation of the desired TMVR device. The secondary outcome was the absence of acute LVOT obstruction after TMVR. RESULTS: A total of 12 patients underwent ASA and all but 1 (n = 11, 91.6%) achieved the primary outcome of having sufficient predicted neo-LVOT area to proceed with TMVR. The mean increase in neo-LVOT area after ASA was 126 ± 64 mm2 (median 119.5, interquartile range: 65.0-163.5 mm2 ). Two patients (16.7%) required a permanent pacemaker after ASA. Nine patients went on and underwent TMVR with their respective devices and none had LVOT obstruction after the procedure. Among the remaining three patients, one had insufficient neo-LVOT clearance after ASA, one had unrelated mortality before TMVR, and one had advanced heart failure before TMVR. CONCLUSION: In appropriately selected patients and at centers experienced with ASA, preemptive ASA can achieve sufficient neo-LVOT clearance for TMVR with a variety of devices in approximately 90% of patients.

The Role of Focused 2-Dimensional Echocardiography in Managing Left Ventricular Outflow Tract Obstruction Mimicking Cardiogenic Shock.

Left ventricular outflow tract obstruction (LVOTO) is a common cardiogenic shock (CS) mimic. We present 3 cases of patients presenting with CS following myocardial infarction, exhibiting a poor response to conventional treatment with inotropy and mechanical circulatory support. This triggered echocardiographic assessment by critical care physicians using focused 2-dimensional (2D) echocardiography. This timely assessment identified anterior mitral valve leaflet entrainment into the left ventricular outflow tract (LVOT), causing LVOTO as the underlying shock mechanism. Echocardiographic findings have led to significant changes in management. The patients underwent fluid administration, weaning from inotropy, and mechanical circulatory support explantation, leading to relief of LVOTO and improved hemodynamics. Critical care basic 2D echocardiography accreditations focus on myocardial function and pericardial effusions. Relevant societies administering these accreditations should consider adding LVOT assessment to enable timely diagnosis of this life-threatening CS mimic.

Accessory mitral valve tissue: a differential diagnosis of an obstructive mass on the left ventricular outflow tract.

Accessory mitral valve tissue is a rare congenital cardiac anomaly that is typically discovered incidentally during echocardiographic evaluation prompted by an asymptomatic murmur. This pathology has characteristic echocardiographic elements and is usually associated with other CHD. The decision to perform surgical resection depends on factors such as the degree of obstruction, presence of symptoms, presence of other CHDs, and risk of thrombosis. The researchers hereby present a case of an asymptomatic paediatric patient with accessory mitral valve tissue that produced left ventricular outflow tract obstruction.

Alcohol septal ablation for left ventricular outflow tract obstruction in cardiac amyloidosis: New indication for an established therapy.

Cardiac amyloidosis can occasionally demonstrate an atypical pattern of infiltration, causing asymmetric septal thickening and a left ventricular outflow tract (LVOT) gradient with systolic anterior motion (SAM) of the mitral valve resembling obstructive hypertrophic cardiomyopathy. We present a case of a 70-year-old man with cardiac light-chain amyloidosis and LVOT obstruction successfully treated with alcohol septal ablation (ASA). Following the procedure, he reported significant improvement in his heart failure symptoms as well as improvement in LVOT gradient and SAM of the mitral valve. This case demonstrates that ASA is a technically feasible and effective procedure for relieving LVOT obstruction in cardiac amyloidosis and can be considered as a treatment option in patients whose symptoms are refractory to medical therapy.

Pulmonary percutaneous valve implantation in large native right ventricular outflow tract with 32 mm Myval transcatheter heart valve.

Pulmonary percutaneous valve implantation (PPVI) is feasible with satisfactory mid-term results in patients with native right ventricular outflow tract (RVOT) and has been increasingly used instead of surgically implantable pulmonary valves. Creating a stable landing zone with a diameter less than the largest commercially available valve (previously available 29 mm and currently available 32 mm) is crucial for technical success of the procedure, limiting the number of suitable candidates for PPVI. We report the case of PPVI with a 32 mm Myval transcatheter heart valve in a patient with a large native RVOT (pre-stented with AndraStent XXL mounted on a 35 × 60 mm valve balloon catheter) lesion who had Tetralogy of Fallot surgically corrected. The post-procedural outcomes of this case were satisfactory with no complications reported during the hospital stay.

Is there a role for endovascular stent implantation in the management of postoperative right ventricular outflow tract obstruction in the era of transcatheter valve implantation?

BACKGROUND: The optimal management pathway for the dysfunctional right ventricular outflow tract (RVOT) is uncertain. We evaluated the long-term outcomes and clinical impact of stent implantation for obstructed RVOTs in an era of rapidly progressing transcatheter pulmonary valve technology. METHODS: Retrospective review of 151 children with a biventricular repair who underwent stenting of obstructed RVOT between 1991 and 2017. RESULTS: RVOT stenting resulted in significant changes in peak right ventricle (RV)-to-pulmonary artery (PA) gradient (39.4 ± 17.1-14.9 ± 8.3; p < 0.001) and RV-to-aortic pressure ratio (0.78 ± 0.22-0.49 ± 0.13; p < 0.001). Subsequent percutaneous reinterventions in 51 children to palliate recurrent stenosis were similarly effective. Ninety-nine (66%) children reached the primary outcome of subsequent pulmonary valve replacement (PVR). Freedom from PVR from the time of stent implantation was 91%, 51%, and 23% at 1, 5, and 10 years, respectively. Small balloon diameters for stent deployment were associated with shorter freedom from PVR. When additional children without stent palliation (with RV-to-PA conduits) were added to the stent cohort (total 506 children), the multistate analysis showed the longest freedom from PVR in those with stent palliation and subsequent catheter reintervention. Pulmonary regurgitation was well-tolerated clinically. Indexed RV dimensions and function estimated by echocardiography remained stable at last follow up or before primary outcome. CONCLUSION: Prolongation of conduit longevity with stent implant remains an important strategy to allow for somatic growth to optimize the risk-benefit profile for subsequent surgical or transcatheter pulmonary valve replacement performed at an older age.

Effect of 3D-printed hearts used in left ventricular outflow tract obstruction: a multicenter study.

OBJECTIVE: The purpose of this research was to explore the application value of a three-dimensional (3D)-printed heart in surgery for left ventricular outflow tract (LVOT) obstruction. METHODS: From August 2019 to October 2021, 46 patients with LVOT obstruction underwent surgical treatment at our institution. According to the treatment method, 22 and 24 patients were allocated to the experimental and control groups, respectively. In the experimental group, each patient's 3D-printed heart model was used for simulated preoperative surgery, and then the Morrow operation was performed. In the control group, only the Morrow operation was performed, without simulated preoperative surgery using a 3D-printed heart model. The intraoperative and postoperative data of patients in the two groups were recorded, and the clinical data of patients were compared between the two groups. RESULTS: The operation time, cardiopulmonary bypass time, intraoperative blood loss, hospitalization time, LVOT pressure difference (LVP), postoperative interventricular septal thickness (IST), aortic regurgitation (AR), systolic anterior motion (SAM), and postoperative left ventricular flow velocity (LVFV) were significantly lower in the experimental group than in the control group (P < 0.05). The inner diameter of the left ventricular outflow tract (IDLV) was larger in the experimental group than in the control group (P < 0.05). There was no significant difference in the postoperative ejection fraction, atrioventricular block rate or complication rate between the two groups (P > 0.05). CONCLUSION: A 3D-printed heart model for simulated surgery in vitro is conducive to formulating a more reasonable surgical plan and reducing the trauma and duration of surgery, thereby promoting the recovery and maintenance of the heart.

Exercise Echocardiography following Septal Myectomy for Hypertrophic Obstructive Cardiomyopathy.

OBJECTIVES: To investigate outcome after septal myectomy and to evaluate long-term hemodynamics with exercise echocardiography. METHODS: This study included 40 consecutive patients operated with septal myectomy for hypertrophic obstructive cardiomyopathy from January 1998 to August 2017 at Skane University Hospital, Lund, Sweden. Perioperative clinical data and echocardiography measurements were reviewed retrospectively. Patients (n = 36) who were alive and living in Sweden were invited for exercise echocardiography to evaluate exercise capacity and hemodynamics, of whom 19 patients performed exercise echocardiography. RESULTS: Overall survival was 100% at 1 year and 96% at 5 years following surgery. Preoperative median resting peak LVOT (left ventricular outflow tract) gradient was 80 mm Hg. Septum thickness was reduced from 22 ± 4 mm preoperatively to 16 ± 3 mm postoperatively (p < 0.001). During exercise echocardiography, the peak LVOT gradient was 8 mm Hg at rest, and increased to 13 mm Hg during exercise echocardiography (p = 0.002). None of the patients had dynamic LVOT obstruction during exercise echocardiography, and there was no clinically significant systolic anterior motion or severe mitral insufficiency during exercise. CONCLUSIONS: Long-term survival following septal myectomy is very good. At long-term follow-up, LVOT gradients were low and exercise echocardiography demonstrated good hemodynamics.

Incidental detection of accessory mitral valve in adolescent with atrial septal defect: Diagnosis with 3D transesophageal echocardiography and excision with transaortic method.

BACKGROUND: Accessory mitral valve tissue (AMVT) is an extremely rare causes left ventricular outflow tract (LVOT) obstruction and is usually incidentally detected in childhood. It is often associated with other cardiac and vascular congenital malformations. CASE PRESENTATION: In this case, we present a 15-year-old girl was diagnosed with AMVT by transesophageal echocardiography, resulting in LVOT obstruction during systole. Interestingly enough, the patient's accessory mitral valve remained undetected for years until he became symptomatic for wide ASD. Successful closure of the ASD with resection of the AMVT was performed with a transaortic approach. The patient was hemodynamically stable postoperatively. There were no abnormalities in the mitral valves and LVOT. CONCLUSION: It was also unusual to see AMVT with ASD instead of other frequently associated other congenital anomalies. Accessory mitral valve should be considered a rare but important cause of left ventricular outflow tract obstruction in childhood.