Subaortic Stenosis Research Articles

Contemporary Clinical Characteristics, Imaging, Management, and Surgical and Nonsurgical Outcomes of Adult Patients With Subaortic Stenosis.

Subaortic stenosis (SAS) is characterized by a fibromuscular membrane located just below the aortic valve, causing fixed outflow tract obstruction. There is a paucity of studies evaluating this condition. This cohort study reviewed the contemporary characteristics and outcomes of SAS in adult patients in a single large referral center. We retrospectively studied adult patients with SAS evaluated at our center during 2011 to 2022. The primary outcome was all-cause mortality and heart failure hospitalizations during follow-up, with secondary end points including recurrence of SAS and repeat surgery after initial SAS surgery. Among 484 patients with SAS, key characteristics included mean age 55±18 years, 67.5% female, left ventricular outflow tract peak velocity 352±140 cm/s and gradient 57±40 mm Hg, left ventricular ejection fraction 60%±14%, 54.8% had prior SAS surgery, and 45.1% had surgery during follow-up. Over a median follow-up of 5.5 (1.5-12.3) years, 11.5% (n=56) died, 6.8% (n=33) had heart failure hospitalizations, 8.0% (n=39) experienced SAS recurrence, and 14 (5.9%) underwent repeat SAS surgery. Multivariable analyses identified older age per 10-years (hazard ratio [HR], 1.37 [95% CI, 1.12-1.68]) and baseline New York Heart Association class (HR, 2.48 [95% CI, 1.54-3.99]) to be statistically significantly associated with the primary end point; higher body mass index, New York Heart Association class, and peak left ventricular outflow tract gradient were also statistically significantly associated with SAS recurrence and redo surgery. Almost half of patients with SAS had surgery in the past or during follow-up, and a significant minority had mortality or morbidity events during follow-up. Identified prognosticators warrant further research to guide management.

Development of Novel 3D Spheroids for Discrete Subaortic Stenosis.

In this study, we propose a new method for bioprinting 3D Spheroids to study complex congenital heart disease known as discrete subaortic stenosis (DSS). The bioprinter allows us to manipulate the extrusion pressure to change the size of the spheroids, and the alginate porosity increases in size over time. The spheroids are composed of human umbilical vein endothelial cells (HUVECs), and we demonstrated that pressure and time during the bioprinting process can modulate the diameter of the spheroids. In addition, we used Pluronic acid to maintain the shape and position of the spheroids. Characterization of HUVECs in the spheroids confirmed their uniform distribution and we demonstrated cell viability as a function of time. Compared to traditional 2D cell cultures, the 3D spheroids model provides more relevant physiological environments, making it valuable for drug testing and therapeutic applications.

Clinical features and surgical outcomes of membranous subaortic stenosis in three siblings: a case series and literature review

Introduction: Subvalvular aortic stenosis (SAS) is a rare heart condition that can cause LVOT obstruction and lead to serious complications. While surgery is the main treatment, recurrence is a concern. This case series highlights the challenges in managing SAS in young patients. Case Series: Three young brothers presented with symptoms of shortness of breath and chest tightness. All were diagnosed with membranous SAS through echocardiography and Doppler ultrasound. Surgical intervention was performed to remove the obstruction, but all three patients experienced recurrence within two years. Discussion: This case series of three brothers suggests a genetic predisposition. Symptoms included exertional dyspnea and chest tightness, diagnosed via echocardiography. Surgical intervention is the primary treatment, but its timing is debated due to recurrence risks and complications. Conclusions: This case series suggests a possible genetic predisposition to SAS. Despite successful initial surgery, the high recurrence rate highlights the need for improved management strategies and long-term follow-up. Further research is crucial to understand the causes of recurrence and optimize treatment for children with SAS.

Comprehensive Review of Shone's Syndrome: Pathophysiology, Clinical Manifestations, and Management Strategies

Shone's syndrome, a rare congenital heart disease, encompasses a complex array of obstructive lesions within the left heart. First described in 1963, this syndrome typically presents with a combination of supravalvular mitral ring, parachute mitral valve, subaortic stenosis, and coarctation of the aorta. The intricate nature of these anomalies presents significant diagnostic and therapeutic challenges. This review aims to elucidate the pathophysiological mechanisms underlying Shone's syndrome, provide a detailed account of its clinical manifestations, and discuss current management strategies, including surgical and medical interventions. Through an in-depth analysis of existing literature, we seek to enhance understanding and improve outcomes for patients afflicted with this multifaceted condition.

Surgical repair of an aortopulmonary window and subaortic stenosis in an adolescent: case report

Surgical repair of an aortopulmonary window and subaortic stenosis in an adolescent: case report

Storytelling of Hypertrophic Cardiomyopathy Discovery.

The discovery of hypertrophic cardiomyopathy (HCM) dates back to 1958, when the pathologist Donald Teare of the St. George's Hospital in London performed autopsies in eight cases with asymmetric hypertrophy of the ventricular septum and bizarre disorganization (disarray) at histology, first interpreted as hamartoma. Seven had died suddenly. The cardiac specimens were cut along the long axis, similar to the 2D echo. In the same year, at the National Institute of Health U.S.A., Eugene Braunwald, a hemodynamist, and Andrew Glenn Morrow, a cardiac surgeon, clinically faced a patient with an apparently similar morbid entity, with a systolic murmur and subaortic valve gradient. "Discrete" subaortic stenosis was postulated. However, at surgery, Dr. Morrow observed only hypertrophy and performed myectomy to relieve the obstruction. This first Braunwald-Morrow patient underwent a successful cardiac transplant later at the disease end stage. The same Dr. Morrow was found to be affected by the familial HCM and died suddenly in 1992. The term "functional subaortic stenosis" was used in 1959 and "idiopathic hypertrophic subaortic stenosis" in 1960. Years before, in 1957, Lord Brock, a cardiac surgeon at the Guy's Hospital in London, during alleged aortic valve surgery in extracorporeal circulation, did not find any valvular or discrete subaortic stenoses. In 1980, John F. Goodwin of the Westminster Hospital in London, the head of an international WHO committee, put forward the first classification of heart muscle diseases, introducing the term cardiomyopathy (dilated, hypertrophic, and endomyocardial restrictive). In 1995, the WHO classification was revisited, with the addition of two new entities, namely arrhythmogenic and purely myocardial restrictive, the latter a paradox of a small heart accounting for severe congestive heart failure by ventricular diastolic impairment. A familial occurrence was noticed earlier in HCM and published by Teare and Goodwin in 1960. In 1989-1990, the same family underwent molecular genetics investigation by the Seidman team in Boston, and a missense mutation of the β-cardiac myosin heavy chain in chromosome 14 was found. Thus, 21 years elapsed from HCM gross discovery to molecular discoveries. The same original family was the source of both the gross and genetic explanations of HCM, which is now named sarcomere disease. Restrictive cardiomyopathy, characterized grossly without hypertrophy and histologically by myocardial disarray, was found to also have a sarcomeric genetic mutation, labeled "HCM without hypertrophy". Sarcomere missense mutations have also been reported in dilated cardiomyopathy (DCM) and non-compaction cardiomyopathy. Moreover, sarcomeric gene defects have been detected in some DNA non-coding regions of HCM patients. The same mutation in the family may express different phenotypes (HCM, DCM, and RCM). Large ischemic scars have been reported by pathologists and are nowadays easily detectable in vivo by cardiac magnetic resonance with gadolinium. The ischemic arrhythmic substrate enhances the risk of sudden death.

Clinical presentation and surgical outcomes in patients with Shone's complex: a systematic review.

Shone's complex comprises ofa combination of congenital cardiac anomalies causing obstructions in the left ventricle's inflow and outflow tracts. This systematic review aims to evaluate the clinical features and surgical outcomes of Shone's complex. An electronic literature search of PubMed and Scopus was performed to identify relevant studies related to the presentation, management, and outcomes of Shone's complex. Two reviewers independently performed selection. Data on study characteristics, participant demographics, interventions, outcomes, and follow-up durations were extracted and analyzed. A total of 691 papers were identified, with 18 studies included in the final analysis. The majority of the studies (n = 12) focused on the pediatric age group. The most common clinical presentations were coarctation of the aorta (n = 17) and mitral stenosis (n = 12). Surgical interventions often involved staged approaches, prioritizing outflow before inflow obstructions. Mitral valve repair was preferred over replacement due to better long-term outcomes (n = 8). Biventricular repair was recommended due to improved postoperative outcomes, but often needed reoperations. Reoperations were common, primarily due to recurrent coarctation (n = 10), subaortic stenosis (n = 8), and mitral valve dysfunction (n = 7). Pulmonary hypertension (n = 10) and arrhythmias (n = 11) were significant complications. Most patients were in modified Ross/NYHA functional class 1 on follow-up. Mortality rates ranged from 4 to 28%, with better outcomes associated with early and strategic surgical interventions. Early diagnosis and biventricular repair were associated with better outcomes while transplantation was often an eventuality. Standardized diagnostic criteria, long-term follow-up, and consensus guidelines are needed to improve the management of this congenital heart disease.

Use of two- and three-dimensional echocardiography for assessment of the left ventricular outflow tract and aortic orifice areas in dogs

Introduction/objectivesIn clinical practice, dogs are screened for subaortic stenosis (SAS) using two-dimensional (2DE) and Doppler echocardiography. There is no accepted antemortem diagnostic criterion to distinguish between mild SAS and unaffected, therefore additional means of evaluating the left ventricular outflow tract (LVOT) and aorta may be desirable. This study sought to determine and compare LVOT and aortic orifice areas using 2DE and three-dimensional echocardiography (3DE) in apparently healthy dogs of various breeds and somatotypes. Animals, materials, and methodsSixty-nine healthy, privately-owned dogs. The LVOT and aortic orifice areas were determined using 2DE aortic valve (AV) diameter-derived area; the continuity equation (CE); and 3DE planimetry of the LVOT, AV, sinus of Valsalva, and sinotubular junction. Orifice areas were indexed to body surface area (BSA). ResultsObtaining 3DE images and performing planimetry were feasible in all dogs. The mean indexed area measured using the 2DE AV diameter (2.85 cm2/m2) was significantly lower than that derived from 3DE AV planimetry (3.85 cm2/m2; mean difference, 1.00 cm2/m2; P<0.001). There was poor agreement between the effective area calculated using the CE and the anatomic areas calculated using 2DE AV diameter and 3DE planimetry. The area calculated using the CE was less than all other calculations of area. Interobserver and intraobserver repeatability and reproducibility for 3DE planimetry were excellent. ConclusionsMethods for determining aortic orifice areas in dogs are not interchangeable, and this must be taken into account if these methods are investigated in the evaluation of dogs with SAS in the future.

Clinical Application of Exercise Stress Echocardiography in an Outpatient Pediatric Population.

Background: Exercise stress echocardiography (ESE) is commonly employed in adults, but its applicability in pediatric populations remains to be clarified. Methods: A total of 309 consecutive children (C), with a mean age of 14.1 ± 2.6 years (range 6-17 years), underwent treadmill ESE starting in 2002. They were divided into two groups: Group I comprised 258 children, including 237 with symptoms related to exercise (such as chest pain, fatigue, lipothymia/syncope, or one aborted sudden death), 15 with electrocardiogram (ECG) abnormalities, and 6 with a positive ECG stress test showing ST changes. Group II consisted of 10 asymptomatic children whose parents requested routine screening, 11 with symptoms unrelated to exercise, 12 with a family history of sudden death, and 17 with known pathologies (including 10 with hypertrophic cardiomyopathy, 2 with aortic coarctation, and the remainder with various conditions, such as Cortriatriatum sinister, pulmonary stenosis, subaortic stenosis, bicuspid aortic valve, left ventricular hypertrophy related to arterial hypertension, and aortic switch operation). Regional wall motion abnormalities (RWMAs) and transvalvular or intraventricular (IVG) gradients were assessed using 2D and continuous-wave Doppler, respectively, in all cases. Results: The success rate was 100% (309/309). Stress-induced RWMAs were observed in two children. A significant IVG (>30 mmHg) was detected in 101 out of the 258 children (39%) in Group I, who presented with exercise-related symptoms, ECG abnormalities, or positive stress ECG. In Group I, the odds ratio (OR) of ESE reproducing the symptoms in children with IVG compared to those without IVG was 8.22 (95% CI: 4.84-13.99, p < 0.001). Conclusions: Treadmill ESE is both feasible and safe for pediatric populations. RWMAs demonstrated limited utility in our cohort of children, while IVG induced by exercise was frequently observed in symptomatic children.

Echocardiographic findings in apparently healthy Czechoslovakian wolfdogs

IntroductionTo echocardiographically evaluate a large number of apparently healthy Czechoslovakian wolfdogs (CWDs) to identify possible subclinical cardiac abnormalities and to generate reference intervals. AnimalsOne-hundred and seventeen apparently healthy client-owned CWDs. Materials and methodsStandard two-dimensional, M-mode, and Doppler echocardiographic measurements were obtained on non-sedated, manually restrained standing dogs. Animals with no relevant echocardiographic abnormalities were used to generate reference intervals. Echocardiographic variables were compared between males and females and between dogs with and without mitral regurgitation (MR). Results and discussionAmong the 117 CWDs, 103 dogs were used to generate reference intervals. The 14 dogs with abnormalities had more than trivial MR (12 dogs), subaortic stenosis (one dog), and equivocal subaortic stenosis (one dog). The 44 males were heavier than 59 females (P<0.001) and had a larger maximum left atrial dimension (P=0.015), left ventricular internal dimension at end-diastole (P<0.001) and systole (P<0.001), and thicker interventricular septum thickness at end-diastole (P=0.016). A positive linear correlation was identified between bodyweight and aortic root and left atrial diameters and left ventricular dimensions and between age and aortic root and left atrial diameter and peak late transmitral flow velocity. A negative linear correlation was identified between age and peak early transmitral flow velocity and the ratio between peak early and late transmitral flow velocities. No differences in echocardiographic-derived cardiac dimensions were detected between healthy dogs and dogs with more than trivial MR. ConclusionsIn this population of CWDs, subclinical cardiac abnormalities were uncommon, and they were mainly classified as MR.

Individualised surgical treatment strategy for subaortic stenosis.

The clinical data of patients with subaortic stenosis who underwent surgical treatment in our centre in the past 12 years were reviewed. The short-term and long-term clinical outcomes were analyzed, and the long-term outcomes of different surgical methods for subaortic stenosis were compared to determine the optimal surgical treatment strategy for subaortic stenosis. From December 2010 to December 2022, 90 patients undergoing surgical treatment for subaortic stenosis in our hospital were enrolled. There were 55 males and 35 females with a median age of 72 (46,132) months and an average surgical weight of (21.35 ± 15.84) kg. According to the operation method, 90 patients were divided into group A (50 patients with simple subaortic membrane resection) and group B (40 patients with subaortic membrane and muscle resection or modified Konno procedure). There were three early deaths (3.33%). One late death occurred in group B. There was no significant difference in long-term survival rate between the two groups (p = 0.904). The preoperative left ventricular outflow tract pressure gradient in group B was (91.56 ± 36.98) mm Hg, which was higher than that in group A(51.13 ± 36.04)mm Hg(p < 0.001). There was no significant difference in immediate postoperative left ventricular outflow tract pressure gradient between group B [(5.44 ± 8.43) mm Hg] and group A [(7.82 ± 13.44) mm Hg] (p = 0.343). In the long-term follow-up, left ventricular outflow tract pressure gradient in group B was (5.86 ± 9.53) mm Hg, which was not statistically significant compared with group A (8.83 ± 14.52) mm Hg (p = 0.294). Eleven patients with moderate or greater aortic regurgitation (group A/group B: 3/8) underwent simultaneous aortic valvuloplasty. In group B, moderate or greater aortic regurgitation was significantly improved immediately after operation (p = 0.013) and was not significantly aggravated in long-term follow-up (p = 0.083), and there was no significant improvement in group A after operation and long-term follow-up. According to the different anatomical lesions of left ventricular outflow tract, the individualised surgical treatment strategy for patients with subaortic stenosis can achieve good long-term outcomes. The long-term survival rate and freedom from reoperation due to late left ventricular outflow tract obstruction after simple subaortic membrane resection and extended left ventricular outflow tract resection are comparable. For patients with moderate or greater aortic regurgitation before extended left ventricular outflow tract resection, simultaneous aortic valvuloplasty is beneficial to improve postoperative aortic valve function.

Perioperative and Anesthetic Considerations in Shone's Complex.

Shone's complex is a congenital cardiac disease consisting of the following four lesions: parachute mitral valve, supravalvar mitral ring, subaortic stenosis, and aortic coarctation. Though not all components are required for a diagnosis, the end result is both left ventricular inflow and outflow obstruction, which typically present in patients as congestive heart failure. The complex pathology requires careful management and surgical decision-making to ensure an optimal outcome. This review will focus on the anatomy, physiology, and perioperative anesthetic management of patients with Shone's complex.

Subaortic Stenosis in Association with Patent Ductus Arteriosus in a Young Woman from the Andes Region

Subaortic Stenosis in Association with Patent Ductus Arteriosus in a Young Woman from the Andes Region

Long-term outcomes and risk factors for reoperation after subaortic stenosis resection in children and adults

Abstract Background Sub-valvular aortic stenosis (SAS) is an extremely heterogeneous form of left ventricular outflow tract (LVOT) obstruction, which can lead to aortic valve damage. Although corrective surgery is considered the most effective treatment, rates of recurrence and reoperation are still high. Previous studies have focused on predictors of reoperation in several subgroups of patients with SAS, but rarely in the whole population of patients with SAS. Purpose We sought to describe long-term outcomes after SAS resection and to determine the predictors of reoperation after successful primary resection. Methods We retrospectively reviewed the records of patients who underwent SAS resection between 1994 and 2021 at our institution with at least 12 months’ follow-up. Patients with a single-ventricle physiology and idiopathic hypertrophic cardiomyopathy were excluded. Demographic, surgical and echocardiographic data were analyzed. Outcomes were reoperation after successful primary resection, death and morbidities, including postoperative complete heart block and aortic regurgitation (AR) grade at latest follow-up. Results Seventy-six patients (paediatric, n = 72 and adult, n = 4) who underwent SAS resection were included in the analysis. Median length of postoperative follow-up was 11.1 years (IQR range: 7.3 – 15.7 years), with two late deaths. Reoperation due to recurrent obstruction or severe AR occurred in 24 patients (31.6%). Median time to reoperation was 7.5 years (IQR range: 3.6 – 11 years). Overall freedom from reoperation at 5 years and 10 years was 84.6% and 69.1% respectively. Gender and association with other cardiac defects did not differ significantly between those with reoperation and those without. In multivariate analysis, independent predictors of reoperation were age at first surgery younger than 5 years (HR 3.54, 95% CI 1.06 – 11.83; P = 0.040) and tunnel-type lesions (HR 4.42, 95% CI 1.70 – 11.51; P = 0.002). Three patients (3.9%) had complete heart block and required placement of an implantable pacemaker. Following SAS resection, progression of AR was common (39/68, 57.3%) but only 5 patients (7.3%) developed sufficient regurgitation to require surgical repair or replacement. Conclusions Reoperation is not infrequent after surgical relief of SAS and reaches a plateau after 10 years. Younger age at first surgery and tunnel-type SAS independently predict reoperation. Progression of AR after corrective surgery of SAS is common, but fortunately only a minority of patients develop hemodynamically significant AR requiring reintervention.

Abstract 17470: Comparison of Outcomes for Adult Patients With Subaortic Stenosis by Surgical or Medical Management: Single-Center Cohort Study

Introduction: Surgery is recommended subaortic stenosis (SAS) patients with severe left ventricular outflow tract obstruction and symptoms, left ventricular dysfunction and sometimes aortic regurgitation, although how surgery modifies patient prognosis is not well understood. We compared the outcomes of SAS based on past and follow-up treatment disposition. Methods: This is a retrospective observation study of adult patients (≥ 18 years) evaluated for SAS on transthoracic echocardiography at our institution during 1/1/2001 to 6/30/2022. Patients were divided into three groups: 1. Patients with prior SAS surgery at index visit; 2. Patients who underwent surgery during follow-up without prior SAS surgery; and 3. Patients managed medically. Primary follow-up endpoint all-cause mortality and secondary endpoint heart failure (HF) hospitalization were compared between groups. Results: There were a total of 115, 106, and 263 patients in group 1, 2, and 3 respectively. The mean age was 45.7±20 years and 67.1% were females. Over median follow-up of 5.5 years, there were 8, 6 and 42 deaths, 3, 9 and 21 heart failure hospitalization, and 20, 15, and 25 SAS recurrences in groups 1, 2, and 3, respectively. Multivariate analysis showed that patients with shortness of breath (odds ratio 3.64, 95% confidence interval 1.20-11.05, P=0.02) and those who are treated medically (1.77 (1.03-3.05), P=0.03) are associated with higher rates of composite death and HF hospitalization. The figure illustrates the Kaplan-Meier survival curves for the primary and secondary endpoint. Group 3 had significantly worse all-cause mortality (P=0.04) and heart failure hospitalization (P=0.03) rates during follow-up. Conclusions: The cohort of adult SAS patients that were managed medically were associated with worse prognosis.

Anesthetic management and complications of severe subaortic stenosis balloon valvuloplasty in dogs

Anesthetic management and complications of severe subaortic stenosis balloon valvuloplasty in dogs

False Aneurysm of The Ascending Aorta Following Open Heart Surgery in an 8- Year-Old Boy: A Case Report

This case report describes an 8-year-old boy with a prior history of open heart surgery for sub-aortic stenosis who presented with shortness of breath and chest pain four months post-operation. Echocardiography and AngioTDM revealed a large false aneurysm of the ascending aorta. Closure of the communication orifice was successfully achieved using ADO II 6/6, with subsequent coagulation of the blood within the false aneurysm and thrombus formation.

Subaortic stenosis and recurrence: what we can influence and what nature decides.

Subaortic stenosis and recurrence: what we can influence and what nature decides.

Surgical Considerations in Shone Complex.

Shone complex is defined by 4 anomalies: parachute mitral valve, supravalvar mitral ring, subaortic stenosis, and coarctation of the aorta. Establishing a clear definition is one of the principal challenges in the study of Shone complex as not all patients have all lesions. The essential feature of Shone complex is multilevel left-sided obstruction involving both the left ventricular inflow and outflow. This anatomic variability is reflected in the clinical presentation as signs of left ventricular inflow obstruction are often masked by outflow obstruction and the multilevel nature of the condition is thus underappreciated. Surgical treatment is often stepwise addressing the outflow obstruction first. In this review, geared to the pediatric cardiac anesthesiologist, we review the pathophysiology, diagnosis, treatment, and outcomes of Shone complex.

Un cas rare de complexe de Shone incomplet chez un homme de 35 ans avec un morphotype marfanoïde et revue de la littérature

Shone syndrome is a rare and complex congenital heart disease. It is characterized in its complete form, by a constellation of the four potentially obstructive lesions of the left heart side. Incomplete Shone's complex includes 2 or 3 of the characteristic lesions which, include a supravalvular mitral membrane, valvular mitral stenosis (MS) by a parachute mitral valve (PMV), subaortic stenosis and aortic coarctation (Coa). We describe here, the case of a 35-year-old man, hospitalized for chronic dyspnea and in whom, the diagnosis of incomplete Shone's complex is retained by echocardiographic analysis. Observed lesions include a parachute mitral valve responsible for mild regurgitation and moderate mitral stenosis, bicuspid aortic valve, and pseudo interruption of the aorta with dilatation of the ascending aorta and a patent ductus arteriosus. This case is the 2nd on 3942 patients in Drighil congenital heart disease registry.