Discrete Subaortic Stenosis Research Articles

Long-Term Pediatric Outcome of Isolated Discrete Subaortic Stenosis

Background The management of pediatric discrete subaortic stenosis remains controversial. Objectives Document the natural history and surgical outcomes for discrete subaortic stenosis to adolescence. Methods Retrospective review of clinical and echocardiographic findings in 74 patients diagnosed in childhood between 1985 and 1998. Results Twenty-five patients were followed only medically for 9.4 ± 0.9 years to 15.9 ± 0.6 years of age. Their echocardiographic left ventricular outflow peak gradient did not progress, 19 ± 1.4 (SEM) vs 20 ± 2.3 mm Hg. The proportion with aortic insufficiency (AI) increased (4% to 52%). Forty-nine patients were operated for discrete subaortic stenosis at 7.8 ± 0.6 years. Their peak gradient at diagnosis was 36 ± 3 mm Hg with AI in 33%. Preoperatively their peak gradient progressed to 60 ± 5 mm Hg with AI in 82%. Assessment 6.2 ± 0.5 years postoperativly showed a peak gradient of 14 ± 2 mm Hg with AI in 88%. Ten patients required reoperation for recurrent discrete subaortic stenosis, 3 acquired complete heart block, and 1 developed endocarditis. There was no mortality. At diagnosis, surgical patients were younger, had greater peak gradients, and greater incidence of AI, than those followed only medically. The progression of discrete subaortic stenosis was positively associated with severity of obstruction and negatively associated with older age at diagnosis. The risk of having surgery over time was associated with greater preoperative obstruction and presence of AI. Conclusions Many pediatric patients with mild discrete subaortic stenosis exhibit little progression of obstruction and need not undergo immediate surgery. Others with more severe stenosis may progress precipitously and will benefit from early resection.

A Case of Successful Valve Repair for Aortic Insufficiency Associated with Discrete Subaortic Stenosis

Discrete subaortic stenosis (DSS) is an uncommon form of left ventricular outflow tract obstruction especially in adulthood. Moreover, aortic regurgitation (AR), which is a common sequence of DSS, requiring surgical correction is extremely rare. We report the case of a 33-year old man who had severe DSS accompanied with moderate aortic insufficiency. He underwent successful surgery including relief of DSS and aortic valve repair. Although careful follow-up is mandatory for recurrent AR and DSS, our approach was thought to be feasible for a young adult patient with DSS complicated with AR.

318 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 is 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 don’t 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) allows an adequate screening of patients that will require early operation.

Medical Management of Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common genetically transmitted cardiomyopathy. The underlying cause of HCM has been attributed to a number of mutations within genes encoding primarily for sarcomeric proteins, which lead to a heterogeneous phenotype of left ventricular hypertrophy in the absence of other causes (eg, hypertension, aortic stenosis, or a discrete membranous subaortic stenosis). Symptoms may range from mild to severely limiting and consist of dyspnea and chest pain with exertion or at rest, syncope, or even sudden cardiac death (SCD). The majority of patients with HCM are treated medically. The primary aim of therapy is to reduce symptoms, but it should also address the risk of SCD. Throughout the years, numerous medical treatments have been used to achieve symptom control in these patients, and include medications such as β-blockers, calcium channel blockers, amiodarone, disopyramide, and angiotensin receptor blockers. This review provides an overview of the current medical treatment of HCM.

Treatment of severe valvular aortic stenosis and subvalvular discrete subaortic stenosis and septal hypertrophy with Percutaneous CoreValve Aortic Valve Implantation

Percutaneous aortic valve implantation (PAVI) is a procedure gaining popularity and becoming more widely used for the treatment of patients with severe aortic stenosis who are at high risk for surgery. Here we show, for the first time, that a successful and complete elimination of both valvular and subvalvular pressure gradients can be achieved with a slight modification of the valve implantation technique. A 91-year-old woman presented with shortness of breath at rest, effort angina, and pulmonary congestion. Echocardiography revealed calcified aortic stenosis with a peak gradient of 75 mm Hg across the valve, and discrete subaortic stenosis (DSS) and marked hypertrophy of the basal septum with systolic anterior motion of the mitral valve (SAM). The intra ventricular gradient had a dynamic pattern across the DSS and the septal hypertrophy and measured 75 mm Hg. The total gradient across the left ventricular outflow (valvular and subvalvular) was 125 mmHg. PAVI with a 23 mm CoreValve was performed with an intentional lower positioning of the valve towards the LV outflow tract; so that the valve struts cover the subaortic membrane and part of the thickened basal septum. At the end of the procedure, the SAM disappeared, and the left ventricular ouflow was widely open. At 1 month follow up the patient was asymptomatic, no pressure gradient was measured between the LV apex and the aorta. This is the first report of successful treatment of severe valvular aortic stenosis and combined subvalvular aortic stenosis due to DSS and septal hypertrophy with SAM with percutaneous aortic valve implantation.

The role of enucleation with or without septal myectomy for discrete subaortic stenosis

The role of enucleation with or without septal myectomy for discrete subaortic stenosis

EComment: Discrete subaortic stenosis following repair of atrioventricular septal defects

eComment: Discrete subaortic stenosis following repair of atrioventricular septal defects

The role of enucleation with or without septal myectomy for discrete subaortic stenosis

Substantial controversy persists regarding the need and efficacy of a routine myectomy in the treatment of discrete subaortic stenosis. Although some believe myectomy more effectively relieves subaortic narrowing, this is uncertain, and complications, including heart block and aortic valve injury, are concerns. The aims of the study were as follows: (1) to analyze the role of enucleation for relief of subaortic stenosis and the risk factors associated with recurrence and reoperation and (2) to delineate the characteristics of the patients who might benefit from enucleation alone. From January 1990 through May 2007, 221 patients with subaortic stenosis underwent biventricular repair. Of those, 106 patients had discrete subaortic stenosis. The preoperative peak left ventricular outflow tract gradient, as determined by means of transthoracic echocardiographic analysis, was 67.3 +/- 29 mm Hg. Forty patients had previous operations for other intracardiac anomalies. Mean age at repair was 7 years. Sixty-one patients underwent isolated enucleation, and 45 patients underwent concomitant myectomy. Patients with recurrent subaortic stenosis whose first operation was performed elsewhere were excluded from analysis. There was 1 early death and 1 late death. The postoperative peak left ventricular outflow gradient decreased to 12.5 +/- 12.9 mm Hg (P < .001). No patient had development of heart block or required a pacemaker. A recurrent gradient of greater than 30 mm Hg was found in 26 (27%) patients, and 8 (7.5%) patients had reoperations. Actuarial freedom from reoperation rates at 5, 10, and 15 years were 94.7% +/- 1.8%, 89.6% +/- 3.5%, and 84.8% +/- 4.9%, respectively.Of those patients who had not undergone a previous cardiac operation, there were no significant differences in the rates of recurrence (28% vs 27%) or reoperation (4.7% vs 4.4%) between the enucleation group and the concomitant myectomy group. For the patients who had a previous cardiac operation, the concomitant myectomy group had a significantly lower rate of recurrence (44% for enucleation vs 13% for enucleation plus myectomy, P = .031). For those patients undergoing primary operations for discrete subaortic stenosis, routine myectomy does not offer superior relief of left ventricular outflow tract obstruction; enucleation alone provides good results in this selected population. However, in those patients with associated cardiac anomalies, concomitant additional myectomy is recommended.

Tracheal Hypoplasia with a Discrete Subaortic Septal Ridge in a Rottweiler Puppy

Concurrent tracheal hypoplasia and discrete subaortic stenosis are described in a 12-week-old Rottweiler puppy that presumably died of pulmonary edema. A brief literature review and comparison to previously published cases of tracheal hypoplasia in other breeds is presented along with a description of a subaortic septal ridge and comparison to the analogous condition in humans.

Subaortic Stenosis Missed by Invasive Hemodynamic Assessment

We present a case of 61-year-old man that was evaluated for possible aortic stenosis but did not show a left ventricular outflow gradient on invasive assessment in the catheterization laboratory. Transthoracic echocardiography showed subaortic stenosis secondary to a discrete membranous structure in the left ventricular outflow tract. This is the first case in the literature of a patient with discrete subaortic stenosis missed by invasive hemodynamic assessment.

Multiplanar review analysis of three-dimensional echocardiographic datasets gives new insights into the morphology of subaortic stenosis

Associated left ventricular structures may play a role in progression and recurrence of discrete subaortic stenosis. The availability of a new 3D echocardiography tool, multiplanar review (MPR), allows comprehensive analysis of datasets in infinite planes, and detailed examination of anatomy. We sought to evaluate the role of MPR in defining the morphology of subaortic stenosis. Consecutive patients underwent detailed 2 and 3D echocardiographic examination using MPR. Sixteen patients aged 0.7-15.9 years (median 4.57) with diagnosis as follows: isolated subaortic stenosis in nine, additional defects in seven (coarctation of aorta, VSD, mitral, or aortic stenosis). Position and extent of subaortic stenosis was clearly described by multiplanar review in all patients. Additional MPR findings were: abnormalities of mitral valve leaflet or chordal apparatus attachments (14 patients), abnormal ventricular muscle band (11), abnormal increased aorto-mitral separation (two). The aortoseptal angle was significantly decreased in subaortic stenosis, mean 141 +/- 12 degrees , vs. normal subjects, mean 153 +/- 6 degrees , P = 0.02. Surgical findings correlated well with MPR findings. MPR analysis of 3D datasets is a sensitive and accurate mode for delineation of morphological details of discrete subaortic stenosis, providing additional information to 2D echocardiography.

Discrete subaortic stenosis associated with calcific aortic stenosis in the elderly

Discrete subaortic stenosis associated with calcific aortic stenosis in the elderly

Abstract 1924: Longterm Outcome Of Pediatric Patients With Discrete Subaortic Stenosis

INTRODUCTION: We previously reported the clinical outcomes of a large pediatric cohort with discrete subaortic stenosis (SubAS) 1 . While patients with more significant left ventricular outflow tract obstruction (LVOTO) at diagnosis progressed rapidly others with mild LVOTO at presentation showed little progression of obstruction or aortic insufficiency (AI). A limitation of our previous study was a relatively short follow-up period. OBJECTIVE: To extend the follow-up of our previously described cohort with SubAS. METHODS: Information was gathered retrospectively on 71 previously identified patients diagnosed with SubAS from 1985–1998. RESULTS: Current data was available on 61/71 patients. At diagnosis the average age was 5.2±0.5 years (mean±SEM), peak LVOT Doppler gradient (Echograd) was 30±3 mmHg, and AI (all mild) was present in 25%. At last assessment the average age was 15.7±0.4 years. Twenty patients were followed only medically and were last reassessed 9.2±1.0 years after diagnosis at 15.8±0.7 years of age. The mean Echograd was unchanged from diagnosis (19±2 vs. 19±3 mmHg). The incidence of AI on echocardiography (all mild) increased from 5% to 55% although none was detectable by auscultation. Forty-one patients underwent surgery 3.0±0.5 years after diagnosis at 7.4±0.6 years of age. The Echograd at diagnosis was 35±3 and increased to 61±6 mmHg pre-operatively. Ten patients were re-operated 5.7±0.7 years after the first surgery and 2 patients had a second re-operation. The last follow up of the operated patients occurred at 15.7±0.6 years of age. At that time the Echograd was 16±3 mmHg and the incidence of AI by echocardiography had increased to 98% (36 mild &amp; 3 moderate) but was evident on auscultation in only 25%. CONCLUSIONS: This study represents the largest and longest contemporary follow-up of pediatric patients with discrete SubAS. Our results indicate that some patients with SubAS show significant LVOTO at diagnosis and subsequent progression. Surgery in these patients provides good relief of LVOTO but does not eliminate AI. The one third of patients presenting with mild LVOTO and AI show little progression through childhood and adolescence. We suggest that the latter can be safely followed medically. 1) Rohlicek et al. Heart 82:708;1999

Risk Factors for Reoperation After Repair of Discrete Subaortic Stenosis in Children

This study aimed to identify independent predictors of reoperation after successful resection of discrete subaortic stenosis (DSS). Recurrence of DSS has been reported to range from 0% to 55% of patients. Factors associated with recurrence have not been adequately defined. Patients were included if they had a diagnosis of DSS, normal segmental cardiac anatomy, previous resection of DSS, and at least 36 months' follow-up. Demographic, surgical, and echocardiographic data were analyzed. Primary outcome was repeat resection of DSS in patients after successful primary resection. Of 111 subjects who had successful surgical resection of DSS, 16 patients (14%) required reoperation. Median follow-up time was 8.2 years. Form of DSS and gender did not differ significantly between those with reoperation and those without. In multivariate analysis, independent predictors of reoperation that would be available before first surgery were <6 mm distance between the aortic valve (AoV) and the obstruction (hazard ratio [HR] 5.1; p = 0.013) and peak gradient by Doppler > or =60 mm Hg (HR 4.2; p = 0.016). If intraoperative variables are also considered, peeling of the membrane from the AoV or mitral valve at first surgery, <6 mm distance between the DSS and AoV, and peak gradient by Doppler > or =60 mm Hg were independent predictors of reoperation. Proximity of the obstructive lesion to the AoV and severe obstruction determined by preoperative echocardiography, as well as involvement of valve leaflets requiring surgical peeling, predict recurrent DSS requiring reoperation.

Discrete Membranous Subaortic Stenosis Complicated by Infective Endocarditis: A Case Report

Discrete membraneous subaortic stenosis is an uncommon cause of left ventricular outflow tract obstruction. Although its relationship to infective endocarditis is well defined, the expected site of vegetation is over the aortic valve. We report on a 46-year-old man who had a discrete membranous subaortic stenosis, complicated with infective endocarditis, in which the vegetation was over the subaortic membrane and the aortic valve was spared. To our knowledge, this is the first reported case of that entity.

Steepened aortoseptal angle may be a risk factor for discrete subaortic stenosis in adults

Discussion exists whether discrete subaortic stenosis (DSS) is a congenital or acquired cardiac defect. Currently, it is regarded an “acquired” cardiac defect presumably secondary to altered flow patterns due to morphological abnormalities in the left ventricular outflow tract, as have been shown by some studies in the pediatric population. In this report, we demonstrated a steepened aortoseptal angle in adults with DSS without previous cardiac surgery in comparison to controls. Our results strengthen the hypothesis that altered flow patterns due to a steepened aortoseptal angle are a substrate for development of DSS in adults.

Familial membranous subaortic stenosis: Review of familial inheritance patterns and a case report

Discrete subaortic stenosis (DSS) accounts for 8% to 20% of all cases of left ventricular outflow tract (LVOT) obstruction. 1 Familial incidence of DSS, although very rare, signifies the importance of screening in family members. Thus far, a clear inheritance pattern has not been reported in any single pedigree. We have described a family with 2 affected children (out of 3) and have also reviewed the inheritance patterns observed in the reported familial cases of DSS. Most cases of DSS present with systolic murmurs and with time progress to systolic dysfunction. Therefore we also explored the relationship between age and the peak LVOT pressure gradient in the familial cases. Clinical Summary PATIENT 1. A 3-month-old infant presented with recurrent pulmonary infections, congestive heart failure, and failure to thrive. On examination, he had a machinery murmur. Echocardiography revealed a large patent ductus arteriosus, mild pericardial effusion, severe left ventricular hypertrophy (LVH), moderate-to-severe subaortic stenosis, a normal aortic valve, and the presence of a subaortic membrane (Figure E1, A). The peak pressure gradient was 70 mm Hg, and the mean pressure gradient was 45 mm Hg. The child underwent surgical intervention for closure of the patent ductus arteriosus during the same admission and an elective operation for subaortic membrane removal at the age of 21 months. The subaortic membrane, surrounding hypertrophied muscles, and free wall were excised. Histopathology showed fibromuscular tissue fragments exhibiting secondary regenerative changes on a myxoid background. A follow-up echocardiogram showed moderate LVH, a peak pressure gradient of 51 mm Hg, and a mean pressure gradient of 32 mm Hg. PATIENT 2. A 5-year-old, otherwise healthy sister of the proband was found to have a heart murmur. Echocardiography showed the presence of a subaortic membrane (Figure E1, B), moderate aortic stenosis, and moderate LVH. The LVOT pressure gradient was 90 mm Hg, and the mean pressure gradient was 55 mm Hg. She underwent elective surgical excision of the subaortic membrane, hypertrophied muscles, and free wall. Histopathology revealed fibromuscular tissue showing spindle-shaped cells with abundant intercellular connective tissue stroma. Postoperative echocardiography showed moderate aortic valvular stenosis and a peak pressure gradient of 72 mm Hg.

Incidental detection of parvovirus myocarditis at time of resection of discrete subaortic stenosis

We report an asymptomatic 18-month-old boy who underwent surgical resection of the discrete subaortic stenosis. Histopathologic examination of the muscle demonstrated diffuse lymphocytic infiltration of the myocardium. Polymerase chain reaction analysis of blood demonstrated parvovirus. This report highlights that asymptomatic myocarditis may be more prevalent than we realise, and that involvement of the myocardium by parvovirus may be entirely asymptomatic.

Echocardiographic Follow-Up of Children with Isolated Discrete Subaortic Stenosis

This study evaluates the progression of stenosis, onset and progression of aortic regurgitation (AR), and the results of surgical outcomes in children with isolated discrete subaortic stenosis (SAS). The medical records of 108 patients (mean age, 5.5 +/- 3.8 years; range, 3 days to 18 years) with isolated discrete SAS were reviewed. Patients with lesions other than AR were excluded. Very mild stenosis was defined as Doppler peak systolic instantaneous gradient (PSIG) less than 25 mmHg, mild stenosis as 25-49 mmHg, moderate stenosis as 50-75 mmHg, and severe stenosis as more than 75 mmHg. Seventy-eight of 108 patients were followed for 2 months to 14 years (mean, 4.8 +/- 3.7 years; median, 5 years) with medical treatment alone. In these patients, the mean PSIG at last echocardiogram was higher than the mean PSIG at initial echocardiogram (39 +/- 19 vs 31 +/- 12 mmHg, respectively; p < 0.001). Among 24 patients with very mild stenosis at initial echocardiogram, 10 had mild and 2 had moderate stenosis after a mean period of 5.6 years. Among 46 patients with mild stenosis at initial echocardiogram, 11 had moderate and 5 had severe stenosis after a mean period of 4.1 years. Only 1 patient among the 8 patients with moderate stenosis at initial echocardiogram had severe stenosis after a mean period of 2.7 years. Thirty-nine patients (50%) had AR (13% trivial, 33% mild, and 4% moderate) at initial echocardiogram. After a mean period of 4.8 years, 77% of the patients had AR (10% trivial, 53% mild, 9% mild-moderate, and 5% moderate). Twenty-four patients underwent surgery. Preoperatively, mean Doppler PSIG and AR incidence were 64 +/- 17 mmHg and 91% (22/24), respectively. The mean Doppler PSIG was 30 +/- 19 mmHg and AR was present in all of the patients a mean period of 4.1 years after surgery. Two patients underwent reoperation for recurrent SAS and AR. Patients with very mild or mild stenosis may be followed noninvasively every year. One patient of the 8 patients with moderate stenosis progressed to severe stenosis, and moderate AR developed in 2 patients after a mean of 2.7 years. We recommend that patients with moderate stenosis undergo careful evaluation to determine whether surgery is necessary due to the severity of stenosis and AR.

Discrete subaortic stenosis in elderly woman

Discrete subaortic stenosis (DSS) is likely an acquired cardiac disorder which requires anatomic precursors and a genetic background. DSS occurs usually within the first decade, provoking rapidly progressive left ventricular outflow tract obstruction and secondary aortic regurgitation. DSS has been considered for a long time exclusively a disease of infancy and childhood and few reports and small series have described DSS in adulthood and only two cases are reported in elderly. Our case describes a discrete subaortic membranous ridge in an elderly woman with recent onset of dyspnea.