Subaortic Stenosis Research Articles

Persistent left superior vena cava with absent right superior vena cava and discrete subaortic stenosis diagnosed in a patient with sick sinus syndrome: a case report and brief review of the literature

Persistent left superior vena cava with absent right superior vena cava and discrete subaortic stenosis diagnosed in a patient with sick sinus syndrome: a case report and brief review of the literature

A Case of Biventricular Repair with Damus-Kaye-Stansel (DKS) Take-Down after DKS Anastomosis for Interruption of the Aortic Arch and Ventricular Septal Defect with Subaortic Stenosis

A Case of Biventricular Repair with Damus-Kaye-Stansel (DKS) Take-Down after DKS Anastomosis for Interruption of the Aortic Arch and Ventricular Septal Defect with Subaortic Stenosis

Palliative combined cutting and high-pressure balloon valvuloplasty in six dogs with severe, symptomatic subaortic stenosis

Introduction/ObjectivesSevere subaortic stenosis (SAS) is a congenital heart defect in dogs that often results in clinical signs and reduced survival. The objective of this study was to describe characteristics of dogs with severe, symptomatic SAS who underwent combined cutting and high-pressure balloon valvuloplasty (CB/HPBV). Animals, materials, and methodsRetrospective description of the clinical characteristics, CB/HPBV procedural deviations from reported methodology and outcomes in a series of six client-owned dogs with severe, symptomatic SAS. ResultsBreeds included two each of Newfoundland, Golden retriever, and German shepherd. Median age was 10.1 months (range: 5–72.3 months), and median weight was 25.5 kg (range: 21.8–36.4 kg). Before CB/HPBV, clinical signs were present in all dogs; four were managed for congestive heart failure (CHF). Three dogs had concurrent congenital heart disease. Median Doppler-estimated left ventricular outflow tract pressure gradient was pre-operatively 149.7 mmHg (range: 89.9–254.7 mmHg) and post-operatively 134.1 mmHg (range: 83.9–181.2 mmHg). Median aortoseptal angle was steep at 136° (range: 109–143°). Clinical improvement was documented in all dogs, based on temporary discontinuation of diuretics and/or owner-perceived reduction in clinical signs. At the time of writing, three dogs had died suddenly, one was euthanized because of recurrence of clinical signs, and one died in CHF. Median survival time was 26.4 months after procedure (range: 6.3–45.8 months). One dog remained alive at 44 months after procedure. ConclusionsPalliative CB/HPBV is a potential therapeutic option for dogs with severe, symptomatic SAS complicated by concurrent congenital heart disease, arrhythmias, or CHF.

The Surgeon’s View of the Left Ventricular Outflow Tract in Congenital Heart Surgery

Left ventricular outflow tract (LVOT) obstruction is a component of many forms of congenital heart disease, including hypertrophic cardiomyopathy, membranous subaortic stenosis, tunnel subaortic stenosis, and outflow tract obstruction related to atrioventricular septal defects. We have gained a particularly extensive experience with the diagnosis and treatment of hypertrophic cardiomyopathy, having performed septal myectomy in over 3,800 patients. In the setting of this review of LVOT obstruction, we use hypertrophic cardiomyopathy as a template by which other pathologies causing LVOT obstruction can be understood. We review important surgical issues in patient selection, diagnostic evaluation, interpretation of imaging, and operative management. To this end, the review focuses on obstructive hypertrophic cardiomyopathy and then broadens to discuss other pathologies causing LVOT obstruction, with important similarities and differences in their management. These other pathologies share some similar presentations and operative techniques, and at times can be confused with hypertrophic cardiomyopathy, but also have important distinctions of which the surgeon should be aware.

Discrete Left Ventricle Outflow Tract Obstruction in Children: Incidence and Predictors of Recurrence. A Multi-Center Study.

ObjectivesThe purpose of this study is to measure the incidence of recurrence of discrete subaortic stenosis (DSS) after primary resection in two major cardiac centers in Saudi Arabia and to identify risk factors associated with recurrence.MethodsData on 234 patients who were diagnosed with DSS and underwent surgical resection between 1999 and 2018 were retrospectively reviewed. Patient demographics as well as echocardiographic, surgical, and pathological data were compared between patients with recurrence and non-recurrence.ResultsThe overall recurrence incidence after primary resection was 44.87% (N = 105). Most patients were male (59%). The median age at the 1st operation was 60 months (range 3 months to 133 months). The presence of aortic stenosis at the time of diagnosis was significantly associated with recurrence (p-value = 0.002). The overall median peak gradient in which the primary resection was indicated is 60 mmHg (range 11 to 152 mmHg). The median peak gradient pre-operation and post-operation were significantly higher for the recurrence group (p-value=0.018 and p<0.001, respectively). We used univariate and multivariate analysis and controlled for the follow-up time, but there were no significant independent predictors of recurrence.ConclusionThe recurrence rate of DSS after the primary resection is relatively high in this study. Further prospective studies are needed to draw a definite conclusion on risk factors for recurrence after primary resection.

Hemodynamic Performance of Dysfunctional Prosthetic Heart Valve with the Concomitant Presence of Subaortic Stenosis: In Silico Study.

The prosthetic heart valve is vulnerable to dysfunction after surgery, thus a frequent assessment is required. Doppler electrocardiography and its quantitative parameters are commonly used to assess the performance of the prosthetic heart valves and provide detailed information on the interaction between the heart chambers and related prosthetic valves, allowing early detection of complications. However, in the case of the presence of subaortic stenosis, the accuracy of Doppler has not been fully investigated in previous studies and guidelines. Therefore, it is important to evaluate the accuracy of the parameters in such cases to get early detection, and a proper treatment plan for the patient, at the right time. In the current study, a CFD simulation was performed for the blood flow through a Bileaflet Mechanical Heart Valve (BMHV) with concomitant obstruction in the Left Ventricle Outflow Tract (LVOT). The current study explores the impact of the presence of the subaortic on flow patterns. It also investigates the accuracy of (BMHV) evaluation using Doppler parameters, as proposed in the American Society of Echocardiography (ASE) guidelines.

Epidemiological study of congenital heart diseases in dogs: Prevalence, popularity, and volatility throughout twenty years of clinical practice.

The epidemiology of Congenital Heart Diseases (CHDs) has changed over the past twenty years. This study aimed to evaluate the prevalence of CHDs in the population of dogs recruited in a single referral center (RC); compare the epidemiological features of CHDs in screened breeds (Boxers) versus non-screened (French and English Bulldogs, German Shepherds); investigate the association of breeds with the prevalence of CHDs; determine the popularity and volatility of breeds over a 20-year period; analysed the trends of the most popular breeds in the overall population of new-born dogs registered in the Italian Kennel Club (IKC) from 1st January 1997 to 31st December 2017. The RC’s cardiological database was analysed, and 1,779 clinical records were included in a retrospective observation study. Descriptive statistics and frequencies regarding the most representative breeds and CHDs were generated. A logistic regression model was used to analyse the trends of the most common CHDs found in single and in cluster of breeds. The relationship between breed popularity and presence of CHDs was studied. The most common CHDs were Pulmonic Stenosis, Patent Ductus Arteriosus, Subaortic Stenosis, Ventricular Septal Defect, Aortic Stenosis, Tricuspid Dysplasia, Atrial Septal Defect, Double Chamber Right Ventricle, Mitral Dysplasia, and others less frequent. The most represented pure breeds were Boxer, German Shepherd, French Bulldog, English Bulldog, Maltese, Newfoundland, Rottweiler, Golden Retriever, Chihuahua, and others in lower percentage. Chihuahuas, American Staffordshire Terriers, Border Collies, French Bulldogs, and Cavalier King Charles Spaniel were the most appreciated all of which showed a high value of volatility. This study found evidence for the value of the screening program implemented in Boxers; fashions and trends influence dog owners’ choices more than the worries of health problems in a breed. Effective breeding programs are needed in order to control the diffusion of CHDs without impoverishing the genetic pool.

Preoperative Factors That Predict Recurrence After Repair of Discrete Subaortic Stenosis

Several factors predict reintervention for subaortic stenosis (SubAS): age, preoperative left ventricular outflow tract gradient, distance from the obstructive subaortic ridge to the aortic valve, and peeling of membrane from the aortic/mitral valves. We sought to develop a prediction rule to categorize risk of reintervention for recurrent SubAS and guide follow-up in patients with discrete SubAS. We retrospectively reviewed patients who underwent SubAS resection between 1984 and 2016. Our primary outcome was reintervention for recurrent SubAS after discharge. Kaplan-Meier estimates were used for time-to-event analysis of any reintervention. Multivariable models were used to create a prediction rule. We excluded patients without 3 years of follow-up. Of 172 patients, 21 (12.2%) required reintervention. The characteristics predicting reintervention were age younger than 2 years (P < .001), preoperative left ventricular outflow tract gradient of 65 mm Hg or more (P= .011), peeling of membrane from the mitral valve (P < .001), distance from the membrane to the aortic valve of less than 5 mm (P < .001), prior complex operation (P= .035), other left-sided heart lesions (P= .008), and aortic annulus z-score of-2.5 or less (P < .001). Our final prediction rule includes age, membrane to aortic valve distance, and other left-sided heart lesions each scored as 1 point. For patients with a score of 1 or less, 4% required a reintervention compared with 34% with a score of 2 or more. A prediction rule that incorporates the patient's age at the index operation, membrane to aortic valve distance, and associated left-sided heart lesions can determine the likelihood of reintervention for recurrent SubAS.

An image-based computational hemodynamics study of the Systolic Anterior Motion of the mitral valve

Systolic Anterior Motion (SAM) of the mitral valve – often associated with Hypertrophic Obstructive Cardiomyopathy (HOCM) – is a cardiac pathology in which a functional subaortic stenosis is induced during systole by the mitral leaflets partially obstructing the outflow tract of the left ventricle. Its assessment by diagnostic tests is often difficult, possibly underestimating its severity and thus increasing the risk of heart failure. In this paper, we propose a new computational pipeline, based on cardiac cine Magnetic Resonance Imaging (cine-MRI) data, for the assessment of SAM. The pipeline encompasses image processing of the left ventricle and the mitral valve, and numerical investigation of cardiac hemodynamics by means of Computational Fluid Dynamics (CFD) in a moving domain with image-based prescribed displacement. Patient-specific geometry and motion of the left ventricle are considered in view of an Arbitrary Lagrangian–Eulerian approach for CFD, while the reconstructed mitral valve is immersed in the computational domain by means of a resistive method. We assess clinically relevant flow and pressure indicators in a parametric study for different degrees of SAM severity, in order to provide a better quantitative evaluation of the pathological condition. Moreover, we provide specific indications for its possible surgical treatment, i.e. septal myectomy.

Hemodynamics in Adults With the Shone Complex

Patients with Shone complex (SC) have multiple left-sided obstructive lesions and thus are at risk for left ventricular (LV) remodeling, LV diastolic dysfunction and pulmonary hypertension. Yet, to date, there has been no description of hemodynamics in adults with SC. Retrospective chart review of 25 patients with SC who underwent cardiac catheterization at Mayo Clinic, MN between 2002 and 2019 was performed. SC was defined as multiple left-sided obstructive lesions in the presence of an anatomically abnormal mitral valve. Median age was 32 years (22.5, 42) and 15 patients (60%) were female. The majority of patients (84%) had history of coarctation of the aorta, 10 (40%) had subaortic stenosis, 11 (44%) had prior aortic valve replacement, and 10 (40%) had prior mitral valve replacement. Structural disease at the time of catheterization which warranted intervention within the next year was present in 13 patients (52%). The mean LV end-diastolic pressure was 21.3 ± 9.0 mm Hg (>15 mm Hg in 71%), pulmonary artery peak systolic pressure was 55.4 ± 13.4 mm Hg, and the pulmonary artery mean pressure was 37.0 ± 9.4 mm Hg (>20 mm Hg in 96%). During a mean follow-up of 8.3 ± 4.4 years, there were 7 deaths (28%) and 3 additional patients (12%) underwent cardiac transplantation. In conclusion, adults with SC who underwent catheterization showed significant left-sided heart and pulmonary vascular remodeling. Elevated LV end-diastolic pressure and pulmonary artery pressures were highly prevalent. There were high mortality and cardiac transplant rates in our cohort.

Mechanical Mitral Valve Replacement: A Multicenter Study of Outcomes With Use of 15- to 17-mm Prostheses

The aim of this study was to evaluate early and mid-term outcomes (mortality and prosthetic valve reintervention) after mitral valve replacement with 15- to 17-mm mechanical prostheses. A multicenter, retrospective cohort study was performed among patients who underwent mitral valve replacement with a 15- to 17-mm mechanical prosthesis at 6 congenital cardiac centers: 5 in The Netherlands and 1 in the United States. Baseline, operative, and follow-up data were evaluated. Mitral valve replacement was performed in 61 infants (15 mm, n= 17 [28%]; 16 mm, n= 18 [29%]; 17 mm, n= 26 [43%]), of whom 27 (47%) were admitted to the intensive care unit before surgery and 22 (39%) required ventilator support. Median age at surgery was 5.9 months (interquartile range [IQR] 3.2-17.4), and median weight was 5.7 kg (IQR, 4.5-8.8). There were 13 in-hospital deaths (21%) and 8 late deaths (17%, among 48 hospital survivors). Major adverse events occurred in 34 (56%). Median follow-up was 4.0 years (IQR, 0.4-12.5) First prosthetic valve replacement (n= 27 [44%]) occurred at a median of 3.7 years (IQR, 1.9-6.8). Prosthetic valve endocarditis was not reported, and there was no mortality related to prosthesis replacement. Other reinterventions included permanent pacemaker implantation (n= 9 [15%]), subaortic stenosis resection (n= 4 [7%]), aortic valve repair (n= 3 [5%], and aortic valve replacement (n= 6 [10%]). Mitral valve replacement with 15- to 17-mm mechanical prostheses is an important alternative to save critically ill neonates and infants in whom the mitral valve cannot be repaired. Prosthesis replacement for outgrowth can be carried out with low risk.

Multiple left-sided stenotic lesions: outcomes after mitral valve surgery. Arguments for abandoning the eponym 'Shone syndrome'.

Management of patients with left ventricular inflow and outflow stenotic lesions can be challenging. Our purpose was to characterize such patients and review the long-term outcomes of those requiring mitral valve (MV) surgery. We performed a retrospective study of 40 patients with subaortic, aortic and/or arch stenotic lesion(s) who underwent MV surgery between 1985 and 2016. Associated left-sided stenotic lesions included aortic valve stenosis in 20 patients (50%), subaortic stenosis in 19 (47.5%) patients, coarctation in 23 (57.5%) patients and hypoplastic aortic arch in 16 (40%) patients. Nineteen patients (47.5%) had a supravalvular mitral ring and 15 (37.5%) patients had a parachute MV. The overall mortality rate was 32.5% (13 patients) with a mean follow-up of 16.3 ± 1.8 years. Being <6 months of age at the time of MV surgery (P = 0.02) and having had previous neonatal aortic valve and/or arch surgery (P = 0.01) were associated with death. The incidence of reoperation (95% confidence interval) at 1, 5, 10 and 15 years was 38% (23-53%), 54% (38-70%), 68% (53-84%) and 85% (72-98%), respectively. Results after MV surgery for children with associated left-sided stenotic lesions are closely age-related. The need for mitral intervention shortly after the initial aortic valve and/or arch intervention was a predictor of dismal outcomes.

ADAMTS19-associated heart valve defects: Novel genetic variants consolidating a recognizable cardiac phenotype.

Recently, ADAMTS19 was identified as a novel causative gene for autosomal recessive heart valve disease (HVD), affecting mainly the aortic and pulmonary valves. Exome sequencing and data repository (CentoMD) analyses were performed to identify patients with ADAMTS19 variants (two families). A third family was recognized based on cardiac phenotypic similarities and SNP array homozygosity. Three novel loss of function (LoF) variants were identified in six patients from three families. Clinically, all patients presented anomalies of the aortic/pulmonary valves, which included thickening of valve leaflets, stenosis and insufficiency. Three patients had (recurrent) subaortic membrane, suggesting that ADAMTS19 is the first gene identified related to discrete subaortic stenosis. One case presented a bi-commissural pulmonary valve. All patients displayed some degree of atrioventricular valve insufficiency. Other cardiac anomalies included atrial/ventricular septal defects, persistent ductus arteriosus, and mild dilated ascending aorta. Our findings confirm that biallelic LoF variants in ADAMTS19 are causative of a specific and recognizable cardiac phenotype. We recommend considering ADAMTS19 genetic testing in all patients with multiple semilunar valve abnormalities, particularly in the presence of subaortic membrane. ADAMTS19 screening in patients with semilunar valve abnormalities is needed to estimate the frequency of the HVD related phenotype, which might be not so rare.

Discrete subaortic stenosis in an elderly woman: value of transoesophageal and 3D echocardiography.

Discrete subaortic stenosis in an elderly woman: value of transoesophageal and 3D echocardiography.

Unusual Ventriculo-Arterial Alignments and Connections.

In this issue of World Journal for Pediatric and Congenital Heart Surgery, Kari and colleagues present a case of anatomically corrected malposition {S, L, L} with ventricular septal defect and complex subaortic stenosis managed by staged biventricular repair. This rare case with interesting management strategy provides an opportunity to clarify this and related unusual ventriculo-arterial alignments.

Impact of Aortoseptal Angle Abnormalities and Discrete Subaortic Stenosis on Left-Ventricular Outflow Tract Hemodynamics: Preliminary Computational Assessment.

Discrete subaortic stenosis (DSS) is an obstruction of the left ventricular outflow tract (LVOT) due to the formation of a fibromuscular membrane upstream of the aortic valve. DSS is a major risk factor for aortic regurgitation (AR), which often persists after surgical resection of the membrane. While the etiology of DSS and secondary AR is largely unknown, the frequent association between DSS and aortoseptal angle (AoSA) abnormalities has supported the emergence of a mechanobiological pathway by which hemodynamic stress alterations on the septal wall could trigger a biological cascade leading to fibrosis and membrane formation. The resulting LVOT flow disturbances could activate the valve endothelium and contribute to AR. In an effort to assess this hypothetical mechano-etiology, this study aimed at isolating computationally the effects of AoSA abnormalities on septal wall shear stress (WSS), and the impact of DSS on LVOT hemodynamics. Two-dimensional computational fluid dynamics models featuring a normal AoSA (N-LV), a steep AoSA (S-LV), and a steep AoSA with a DSS lesion (DSS-LV) were designed to compute the flow in patient-specific left ventricles (LVs). Boundary conditions consisted of transient velocity profiles at the mitral inlet and LVOT outlet, and patient-specific LV wall motion. The deformation of the DSS lesion was computed using a two-way fluid-structure interaction modeling strategy. Turbulence was accounted for via implementation of the k-ω turbulence model. While the N-LV and S-LV models generated similar LVOT flow characteristics, the DSS-LV model resulted in an asymmetric LVOT jet-like structure, subaortic stenotic conditions (up to 2.4-fold increase in peak velocity, 45% reduction in effective jet diameter vs. N-LV/S-LV), increased vorticity (2.8-fold increase) and turbulence (5- and 3-order-of-magnitude increase in turbulent kinetic energy and Reynolds shear stress, respectively). The steep AoSA subjected the septal wall to a 23% and 69% overload in temporal shear magnitude and gradient, respectively, without any substantial change in oscillatory shear index. This study reveals the existence of WSS overloads on septal wall regions prone to DSS lesion formation in steep LVOTs, and the development of highly turbulent, stenotic and asymmetric flow in DSS LVOTs, which support a possible mechano etiology for DSS and secondary AR.

Mitral Valve Replacement With the 15-mm Mechanical Valve: A 20-Year Multicenter Experience

The aim of this study was to evaluate early and long-term outcomes (mortality and prosthetic valve replacement) after mitral valve replacement with the 15-mm St Jude Medical prosthesis (St Jude Medical, St Paul, MN). A multicenter, retrospective cohort study was performed among patients who underwent mitral valve replacement with a 15-mm St Jude Medical Masters prosthesis at 4 congenital cardiac centers in The Netherlands. Operative results were evaluated and echocardiographic data studied at 0.5, 1, 2, 3, 5, and 10 years after surgery. Surgery was performed in 17 infants. Ten patients (59%) were treated in the intensive care unit before surgery; 8 (47%) were on ventilator support. Median age at surgery was 3.2 months (interquartile range [IQR], 1.2-5.6), and median weight was 5.2 kg (IQR 3.9-5.7). There was 1 early cardiac death and 1 late noncardiac death. Median follow-up time was 9.6 years (IQR, 2.4-13.2), including 8 patients with a follow-up more than 10 years. The first prosthetic valve explantation (n= 11) occurred at a median of 2.9 years (IQR, 2.0-5.4). Other reinterventions were permanent pacemaker implantation (n= 3), subaortic stenosis resection (n= 2), and paravalvular leak repair (n= 1). Prosthetic valve gradients increased from a mean of 5.0 mm Hg (at discharge) to a mean of 14.3 mm Hg (at 5-year follow-up). Mitral valve replacement with the 15-mm prosthesis can safely be performed in infants and even in neonates. Median freedom from prosthesis replacement for outgrowth is 3.5 years. Thromboembolic complications were rare.

Factors determining the nature of progression of discrete fixed subaortic stenosis

In discrete fixed subaortic stenosis, surgery is indicated when the systolic gradient (Gmax) between the left ventricle (LV) and the aorta exceed 50 mmHg or in the presence of significant aortic regurgitation (AR). The aim of this study was to determine the factors that influence the progression of the obstruction and the appearance of AR. Retrospective serial echocardiographic review of 19 patients, mean age 16 years (2 years–38 years), with fixed discrete subaortic stenosis that did not require surgery (initial Gmax at inclusion < 50 mmHg and without any symptom). The mean follow up was 5.42 years. The progression of gradient is defined by the formula (Gmax at follow up–initial Gmax). The mean velocity of increasing of Gmax was 2 mmHg/year. This progression was correlated to the patient's age (cut off = 15 years, r = −0.5 P = 0.02), and the initial value of the Gmax (cut off = 40 mmHg, r = 0.43, P = 0.04). The appearance or the aggravation of aortic regurgitation was determined by: the initial grade of AR ( r = 0.64; P = 0.003), initial Gmax ( r = 0.65; P = 0.002), progression's velocity of G max ( r = 0.47; P = 0.04), and distance between the membrane and the aortic cusps (cut off = 5 mm, r = 0.49; P = 0.03). LV hypertrophy was influenced by the velocity of progression of obstruction (> 2 mmHg/year). The identification of factors determining the evolution of discrete subaortic stenosis (age < 15 years, initial Gmax > 40 mmHg, distance membrane- cusps > 5 mm) allow an adequate screening of patients that will require early operation.

A Case Report of the Shone Syndrome in Association with Coronary Abnormality

Shone syndrome or complex is defined by sequential left-sided heart stenosis, including supravalvular mitral membrane, valvular mitral stenosis (MS) by a parachute mitral valve, subaortic stenosis, and aortic coarctation. It is a rare entity which occurs most frequently in its incomplete form, a 31-year-old man who referred to our adult congenital clinic with a chief complaint of recent chest discomfort. He had a history of hypertension since last year. Echocardiography revealed congenital severe MS (parachute-like mitral valve), two papillary muscles with decreased space between them and underdeveloped lateral papillary muscle. Other findings of echocardiography were bicuspid aortic valve (fusion of the right coronary cusp [RCC] and left coronary cusp) with moderate-to-severe aortic stenosis (AS) and moderate eccentric aortic insufficiency. Deformed aortic arch (gothic arch) and aortic coarctation were also reported in transthoracic echocardiography. We also found an abnormal vessel like density in 5-chamber view that suggested bleb sign and retroaortic course of the left circumflex (LCX). The patient was scheduled for coronary angiography and intervention for coarctation of the aorta, which revealed an abnormally originated LCX from RCC, significant coarctation of the aorta, and significant AS. Aortic coarctoplasty with CP STENT 8 × 39 mounted on balloon Altosa-XL-Gemini 26 × 40 was done in this session. Shone complex is a rare anomaly that may need multiple procedures for correction. Echocardiography is a specially important modality in these patients for diagnosis and evaluation of severity. By this modality, even we can diagnose some coronary artery origin abnormality.

P1321 A case of multiple levels of ventricular obstruction

Abstract Subaortic stenosis (SAS) is a rare entity in adults with unclear etiology and variable presentation. SAS may be presented with symptoms mimicking Hypertrophic Cardiomyopathy (HCM). Often a combination of imaging modalities is needed to distinguish SAS from HCM with obstruction. A 53 years old man, smoker, was referred to our medical center suffering from shortness of breath on exertion. He first presented at another facility with a 2 month history of shortness of breath and chest discomfort during brisk physical activity and the possible diagnosis of HCM was made. On physical examination, a 3/6 systolic murmur was audible along the left sternal border, that became louder with standing and the Valsalva maneuver. The patient had non distended jugular veins, clear lung fields and no ankle edema. The results of laboratory exams did not reveal any pathological sign. The transthoracic echocardiogram revealed significant left ventricular hypertrophy (Interventricular septum 21 mm, Posterior wall 16 mm) with normal left ventricular systolic performance (ejection fraction &amp;gt;70%). The aortic valve was tricuspid and calcified whereas mitral valve was morphologically normal, with systolic anterior motion and mild posterolaterally directed regurgitation. Two systolic gradients, one dynamic, late peaking of 85mmHg and another fixed of 70mmHg were detected in left ventricular outflow track (LVOT). Transesophageal echocardiography was performed for the better evaluation of aortic valve and showed a three level obstruction caused by the systolic motion of the mitral valve towards the hypertrophic septum at LVOT, the presence of a membranous subaortic membrane and the calcified aortic valve respectively. The aortic valve was calcified with a moderate stenosis (0.8cm2 / m2) from 3D planimetry. A Cardiac Magnetic Resonance exam was ordered and confirmed the significance of hypertrophy and the presence of circumferential subaortic membrane. No late enhancement after the administration of Gadolinium was observed. Coronary angiography was performed and demonstrated normal coronary arteries. We hypothesized that the presence of subaortic membrane led to marked myocardial wall thickness and to the destruction of the aortic valve due to turbulent flow in the LVOT. The patient was referred for surgical management Extended septal myectomy combined with complete resection of orbital subaortic membrane were performed. he calcified aortic valve was replaced by bioprosthetic valve No 23mm. The patient tolerated the procedure well with significant symptomatic improvement. TTE performed 1 month postoperatively showed no remarkable LVOT gradient. The results of histopathology and genes investigations are pending. Subaortic membrane is a rare cause of symptoms that can mimic hypertrophic cardiomyopathy. A combination of imaging modalities is needed to distinguish subaortic stenosis from aortic valve stenosis and hypertrophic obstructive cardiomyopathy. Abstract P1321 Figure. Three levels obstruction