Subaortic stenosis is a CHD that can lead to left ventricular hypertrophy, heart failure, and aortic valve damage if left untreated. The gold standard treatment for subaortic stenosis is septal myectomy. However, there is no clear consensus on the surgical margins required for adequate muscle resection. In this retrospective study, we reviewed the records of 83 patients who underwent subaortic stenosis surgery between 2012 and 2020 to investigate the effect of early troponin levels on prognosis. We excluded patients with additional cardiac pathologies, hypertrophic obstructive cardiomyopathy, and valvular aortic stenosis.

Troponin levels were recorded in the early post-operative period, and patients were monitored for complications such as ventricular arrhythmia, left ventricular systolic dysfunction, infective endocarditis, and pacemaker implantation. The troponin levels were significantly higher in the patients who had septal myectomy. The degree of myectomy affected the risk of complications in the early post-operative period and recurrence in the later period. However, when the gradient was substantially or completely removed by myectomy, patients experienced significant symptom improvement in the early post-operative period, and their late survival was equivalent to that of healthy individuals of the same age.

Our findings suggest that monitoring troponin levels in patients undergoing septal myectomy may be beneficial in predicting the risk of complications. However, further studies are needed to establish the optimal surgical technique and extent of muscle resection required for subaortic stenosis treatment. Our study adds to the existing knowledge of the benefits and risks associated with septal myectomy as a treatment option for subaortic stenosis.

Decision-making in congenital cardiac care, although sometimes appearing simple, may prove challenging due to lack of data, uncertainty about outcomes, underlying heuristics, and potential biases in how we reach decisions. We report on the decision-making complexities and uncertainty in management of five commonly encountered congenital cardiac problems: indications for and timing of treatment of subaortic stenosis, closure or observation of small ventricular septal defects, management of new-onset aortic regurgitation in ventricular septal defect, management of anomalous aortic origin of a coronary artery in an asymptomatic patient, and indications for operating on a single anomalously draining pulmonary vein. The strategy underpinning each lesion and the indications for and against intervention are outlined. Areas of uncertainty are clearly delineated. Even in the presence of “simple” congenital cardiac lesions, uncertainty exists in decision-making. Awareness and acceptance of uncertainty is first required to facilitate efforts at mitigation. Strategies to circumvent uncertainty in these scenarios include greater availability of evidence-based medicine, larger datasets, standardised clinical assessment and management protocols, and potentially the incorporation of artificial intelligence into the decision-making process.

Transoesophageal echocardiography is a useful tool for the intra-operative assessment of surgical repair in children with congenital cardiac malformations. We report the case of a subaortic membrane removal in a nine-year-old boy. Three-dimensional transoesophageal echocardiography revealed a mitral perforation created during the procedure.

We report the case of a young woman with a troponin mutation of C to T nucleotide substitution in exon 17 of troponin 2 (TNNT2; c.868C.T; p.Arg288Cys) leading to hypertrophic obstructive cardiomyopathy. Following surgical resection of the outflow obstruction, she had near-complete resolution of her asymmetric left ventricular hypertrophy, such that cardiomyopathy could no longer be diagnosed on echocardiographic grounds. We believe that this unusual case shows important aspects relating to the interplay between genetic and environmental mechanisms and the overlap in the phenotypic spectrum between primary subaortic stenosis and obstructive hypertrophic cardiomyopathy.

We describe our experience with 2 patients having Costello syndrome, aged 11 and 36 months, who suffered systolic anterior motion of the aortic leaflet of the mitral valve and obstructive cardiac hypertrophy requiring surgery, comparing their cardiac characteristics to those described previously. We conclude that the heterogeneous nature of the cardiac hypertrophy in this syndrome can be considered and managed as the sum of a diffuse hypertrophy accessible to beta-blockade, and an asymmetric hypertrophy accessible to surgical myomectomy.

Obstruction of the left ventricular outflow tract continues to represent a challenging surgical problem, particularly in children. Failure to relieve the obstruction by either valvotomy or myectomy requires enlargement of the ventriculoaortic junction and outflow tract. Alternatively, the obstruction can be by passed using an apical valved veritriculo aortic conduit, althoughthis is associatedwith a high rate oflong-term complications. The use of a small xenograft in children is less than ideal because of early calcification, and the insertion of a mechanical valve may be feasible only after considerable enlargement of the ventriculoaortic junction. Aortoventriculoplasty is particularly suited for this purpose, and it is usually associated with good early results. Yet, long-term experience with this procedure, as far as we know, has not been reported previously. We describe our experience with the use of aortoventriculoplasty in four patients, three of whom have been followed-up for more than five years. Two patients have required reoperation for replacement of their prosthetic valves, one for bacterial endocarditis and the other for fracture of a continuous prolene suture which secured the prosthetic valve to the Dacron septal patch. All patients are currently in good health with continuing satisfactory relief of obstruction to their left ventricular outflow tract.

Tetralogy of Fallot is often found in association with a wide variety of other cardiac lesions, but is rarely found in association with lesions causing obstruction to the left ventricular inflow or outflow. Subaortic stenosis has only rarely been reported in association with tetralogy of Fallot. We report a patient with Marfan syndrome who underwent repair of tetralogy of Fallot at five years of age. Discrete and progressive subaortic stenosis developed two years after the surgical correction, in a previously normal and unobstructed left ventricular outflow tract. Surgical removal of the acquired fibrous subaortic shelf was successful. Clinical signs of obstruction within the left ventricular outflow tract after surgical repair of tetralogy of Fallot should prompt further investigation to exclude the onset of acquired subaortic stenosis.

A 64-element phased-array echocardiographic transducer mounted on a sliding carriage was used transthoracically in 11 patients with subaortic obstruction caused by various different morphological substrates. The transducer is moved in a plane from the outflow tract to the apex of the heart in steps of 0.5 to 1.3 mm and records a tomographic slice of the heart at each step. Parallel images are recorded at a frame rate of 25–30 images per second and triggered to heart rate and respiration. A complete cardiac cycle is recorded at each level. The images are digitized and stored in the image-processing computer, which reconstructs the anatomic structures of the heart in a three-dimensional format by means of different gray-scales. Good quality echocardiographic pictures were obtained in 10 of the 11 patients and three-dimensional reconstructions were possible in those 10 patients. The technique is able to display the heart in real-time in any desired plane, and in up to five planes simultaneously, without the need to change the position of the transducer on the chest. Thus the best views with which to display the substrate of subaortic stenosis could be selected. The left ventricular outflow tract could also be displayed in a view similiar to the one obtained by the surgeon during operative procedures for resection of the subaortic stenosis through an incision in the aortic root. Image acquisition took three to five minutes, and three-dimensional reconstruction of various cardiac structures took 20–90 minutes. Display of the subaortic area in three-dimensional format may enhance our understanding of cardiac anatomy and identify the different morphological lesions in the left ventricular outflow tract which cause subaortic obstruction.

We report an unusual form of aortic atresia with a normal sized left ventricle, intact ventricular septum and isolated cleft of the left atrioventricular valve, with abnormal attachments creating both subaortic atresia and massive regurgitation across the left atrioventricular valve. This combination, never described before as far as we are aware, can be considered as an extreme form of subaortic stenosis complicating a very particular type of atrioventricular septal defect.

We report a case of interruption of the aortic arch associated with patency of the arterial duct, restrictive ventricular septal defect, obstruction of the left ventricular outflow due to a discrete subaortic shelf and severe pulmonary arterial hypertension. The patient survived to adulthood, when a complete angiographic diagnosis was made. The subaortic obstruction was treated by percutaneous balloon dilation performed through a right brachial arteriotomy. Correction of the interrupted arch was carried out surgically using a woven Dacron graft from the aortic arch to the descending thoracic aorta associated with ligation of the duct. Hemodynamic studies after one year revealed a marked decrease in pulmonary vascular resistance and a sustained reduction in the gradient across the left ventricular outflow tract. The case is of interest in the light of the unusual survival and the success of staged management of this complex situation.

On the basis of our clinical experience, we hypothesized that the role of mitral valvar anomalies in the development and recurrence of discrete subaortic stenosis might be underestimated. From January 1994 to October 2000, the anatomy of the mitral valve and its relationship to the other components of the left ventricular outflow tract were studied by echocardiography in a series of 73 consecutive patients referred to our institution for surgical correction of discrete subaortic stenosis. In all patients for whom it was considered advisable, surgical correction of the mitral anomaly was performed, together with resection of the fibro-muscular subaortic stenosis. One or more mitral valvar anomalies were found in 35 patients (48%). They could be grouped into five categories: insertion of a papillary muscle into the aortic leaflet, insertion of a papillary muscle into the ventricular wall, “muscularization” of the subaortic portion of the aortic leaflet, anomalous insertion of the valvar tissue into the ventricular wall, and accessory valvar tissue. In all cases with anomalous mitral valvar anatomy, surgical correction was feasible. It consisted of transection of the anomalous papillary muscle or its attachment, resection of accessory valvar tissue, and/or patch enlargement of the aortic leaflet. The incidence of mitral valvar anomalies associated with subaortic stenosis is probably underestimated. Our data suggest that they should be systematically searched for during the evaluation of all cases of subaortic stenosis. Their surgical correction is generally feasible, and might improve the mid and long term results.