Subvalvular aortic stenosis. Apropos of 3 cases

The three cases reported here illustrate the most frequent varieties of infra-valvular congenital aortic stenosis secondary to a fixed obstacle: such as a thin membrane located a few millimeters under the aortic ring; such as a fibro-muscular membrane at some distance of the ring; such as an infra-aortic fibro-muscular tunnel. The clinical symptoms and evolutive risks are reviewed. Ultrasound cardiography enables to make an accurate diagnosis and evaluate the associated lesions. A surgical indication is made in symptomatic forms with a gradient exceeding 40 mmHg. The advantage of early surgery is to decrease the risk of heart failure. The various surgical techniques are presented.     

Subvalvular aortic stenosis

Opinion statement  

Neonatal aortic valvular stenosis. Apropos of 8 cases]

Congenital aortic stenosis presenting in the neonate must be distinguished from the commoner hypoplastic left heart-syndrome, which is beyond surgical correction. It is certainly a serious problem, but early diagnosis and supporting angiography to rule out the presence of an associated left ventricular malformation and to check the volume of the left ventricular cavity should lead to a decision to operate. Out a 4 neonates from this series who were presented for surgery, the 2 survivors had good long-term results.     

Two-dimensional echocardiography in subvalvular aortic stenosis. Apropos of 20 cases

Twenty cases of discrete subvalvular aortic stenosis in children aged from 8 months to 23 years were examined by 2-dimensional echocardiography and cineangiography. Fifteen of these patients subsequently underwent open heart surgery to relieve the obstruction. In 18 cases the obstacle was a fixed stenosis (13 type I, 3 type II and 2 type III) and in two cases, the obstacle was provoked by accessory tissues of the anterior mitral leaflet. The echocardiographic incidences used were the left parasternal long axis, the apical LAO-equivalent, and longitudinal and transverse subcostal views. In type I, fixed subvalvular stenosis, one fine abnormal echo was visualised in the left ventricular outflow tract throughout the cardiac cycle immediately below the aortic valve, best seen on apical views. Twelve of the 13 stenoses of this type were demonstrated by 2D echocardiography. In type II stenosis an abnormal thickened echo was visualised in the left ventricular outflow tract at a distance from the aortic cups. The adherence of this abnormal echo to the anterior mitral leaflet was best demonstrated by apical views. All three cases of this type were demonstrated by echocardiography. Type III stenosis was characterised by widespread narrowing of the subaortic region with irregular borders. Obstruction due to accessory tissues of the anterior mitral leaflet were well demonstrated in left parasternal long axis and apical views. They showed an even rounded mass of echos attached to the anterior aspect of the anterior leaflet prolapsing into the left ventricular outflow tract. Both cases in this series were diagnosed by 2D echocardiography. Therefore, 2D echocardiography with apical and subcostal views is a valuable method for diagnosing subvalvular aortic stenosis and for determining its anatomical type.     

Subvalvular aortic stenosis discovered after surgical repair of an atrioventricular canal in the adult. Apropos of a case

The case of an adult female patient in whom subaortic stenosis was discovered 9 months after surgical correction of a partial atrioventricular canal is reported. The authors describe the difficulties encountered in the pre-operative diagnosis of this uncommon association and the paraclinical methods now available, notably echocardiography, that may help overcome these difficulties.     

Subvalvular aortic stenosis: long-term surgical results

Seventy-six patients, with a mean age of 11.6 years, presenting with congenital subvalvar aortic stenosis were operated upon between 1965 and 1979. Seventy had moderate subvalvular stenosis. Eighty-eight percent had myotomy combined with resection of the obstruction. Five patients (6.6%) died postoperatively. Of 48 survivors followed up between 6 months to 13 years postoperatively (mean 4.2 years), 4 underwent reoperation and 2 of them died. Survival at 5 years and 10 years was 96% and survival without reoperation at 5 years and 10 years was 91%. When last seen, 90% of the patients were asymptomatic, left ventricular hypertrophy on ECG had disappeared in 63%. No patient had atrioventricular block. Two thirds of the patients had no systolic thrill and of 13 patients recatheterized (3.2 years follow-up) 9 had a peak systolic gradient below 50 mmHg. If, postoperatively 60% of the patients had aortic insufficiency versus 31% preoperatively for the whole period, this percentage fell to 33% after 1976. As subaortic stenosis is a progressive disease and late surgical results are correlated to preoperative peak systolic gradient, early surgery is recommended. Close postoperative follow-up is needed since recurrence of aortic stenosis is possible (and acquired aortic insufficiency may persist).     

Subvalvular aortic stenosis associated with valvular aortic regurgitation in young child

Discrete subvalvar aortic stenosis is a variable and progressive disease. Recurrent obstruction may reappear despite the adequacy of surgical excision. Aortic regurgitation is associated with numerous eponymous signs, it is also a complication of discrete subvalvar aortic stenosis and its detection often triggers referral for surgery. It has also been suggested that an infant or young child with a well-defined 30 mm Hg or more peak gradient should have removal of the subvalvar obstruction. We describe a case of subvalvular aortic stenosis associated with aortic regurgitation in a 10-year-old Italian boy.     

Continuous emission Doppler study with spectrum analysis in the evaluation of aortic stenosis in adults. Apropos of 30 cases

The value of continuous wave doppler with spectral analysis for the evaluation of aortic stenosis in adults being controverted, we analyzed prospectively the results obtained in 30 consecutive elderly patients (mean age 63 years) investigated by invasive and non-invasive methods. In 24 patients who underwent both ultrasonic and catheter examinations, the correlation between mean gradients measured by catheterization and calculated separately by doppler was 0.80. For a semi-quantitative evaluation of the aortic valve area, we suggest to use an additional severity index R calculated from doppler data (R = mean gradient/maximal instantaneous gradient) which correlated well (r = -0.68) with the aortic valve area. In our experience, this index makes it possible to separate patients with a less than 0.75 cm2 aortic valve area, as calculated from Gorlin's formula (R greater than 0.65) from patients with a more than 0.75 cm2 aortic valve area (R less than 0.65), irrespective of the associated cardiac index. It is concluded that the doppler ultrasound method provides a highly satisfactory evaluation of transaortic gradient, as well as a semi-quantitative evaluation of the stenotic aortic ostium in the majority of elderly patients with aortic stenosis.     

Subvalvular aortic stenosis: a review of current literature

Subvalvular aortic stenosis (SAS) is one of the common adult congenital heart diseases, with a prevalence of 6.5%. It is usually diagnosed in the first decade of life. Echocardiography is the test of choice to diagnose SAS. Surgical correction is the best treatment modality, and the prognosis is usually excellent. In this review, we describe the pathophysiology, diagnosis, prognosis, and management of SAS with a focus on different pathophysiologic mechanisms, diagnostic approach, and prognosis of the disease by reviewing the current literature.     

Supravalvular aortic stenosis in adults

Supravalvular aortic stenosis in adults, in contrast to the form seen in infants and children, is usually not associated with mental retardation, peculiar facies or severe peripheral pulmonic stenosis. Subtle clinical findings serve to distinguish it from valvular aortic stenosis, a differentiation of great importance if surgery is a consideration. Diagnosis is made by aortic and left ventricular angiograms. The severity of the clinical disease correlates better with abnormalities of the coronary arteries than with the severity of the obstruction, although both are frequently significant. Once symptoms occur, the prognosis is poor without surgical correction. Surgical mortality rates are high, primarily as a result of incomplete preoperative diagnosis.     

Severe calcified aortic stenosis in patients aged 80 or older. Apropos of 65 cases surgically treated

From 1981 to 1989, 65 patients over 80 years were submitted to surgery for severe calcific aortic stenosis. Thirteen patients were in NYHA II, 31 in NYHA III, 21 in NYHA IV. Mean valve area was 0.52 +/- 0.14 cm2 and mean aortic valve gradient was 62 +/- 18 mmHg. Left ventricular function was altered (ejection fraction less than 40%) in 33 patients. Six patients had a previous balloon aortic valvuloplasty. Bioprosthesis were used in all 65 patients associated to CABG (in 5) and mitral valve replacement (in 1). One month mortality was 19 cases (29%) due to cardiac failure (in 10) pulmonary (in 7) and neurological (in only 2) complications. Early mortality was nearly significantly correlated to NYHA stage (p = 0.08) and preop renal insufficiency (p = 0.07). It was significantly correlated to function (40% mortality when ejection fraction less than 40%, 16% in others) and to operations on emergency basis (5 deaths over 6). Hospital morbidity was 68%. There were 5 late deaths. Among the 41 long-term survivors (3 mths-7yrs) 29 are in NYHA I, 10 in NYHA II and 2 in NYHA III due to valve failure. The actuarial survival probability is 65% at one year, 50% at 5 years. In summary good long-term results justify to take a high post operative risk in octogenarians. Early surgery before left ventricular impairment improves the survival.     

Ostium primum and mitral cleft and aortic subvalvular stenosis. Apropos of 2 operated cases]

The two case reports are of children of 10 and 8 years of age with an ostium primum defect, with a mitral cleft and a stenotic fibrous ring below the aortic orifice. In the first case, the cause of the obstruction to left ventricular ejection was found at catheterisation, and in the second case it was an operative finding. In both cases there were large gradients, about 100 mmHg. The subaortic blockage was resected in both cases. A review of the literature has not revealed any similar case.     

Prognosis of Wolff-Parkinson-White syndrome in infants. Apropos of 31 cases

The fate of 31 children (18 boys, 13 girls) whose Wolff-Parkinson-White syndrome (WPW) had been diagnosed before they were 2 years' old (mean 3.4 months) was investigated. The circumstances in which WPW was discovered were: evaluation of a heart disease in 9 cases, attack of orthodromic tachycardia in 16 cases (including one with cardiopathy), and routine electrocardiography in 6 cases. Type A WPW was the most frequent, being found in 20 patients of whom only 3 had a heart disease; type B WPW was present in 11 patients, and 7 of these had a heart disease. Mean follow-up was 5.9 years; 3 children died of other causes than WPW. In patients followed up for more than one year WPW disappeared in 65 p. 100 of the cases (11/17) in the absence of cardiopathy, and in only 14 p. 100 of the cases (1/7) in the presence of cardiopathy. In children who had suffered attacks of tachycardia WPW disappeared in 64 p. 100 of the cases (9/14). When WPW disappeared it was before the age of 1 year in 8 out of 12 cases. Only one child whose WPW had disappeared had further attacks of tachycardia (11 p. 100), while 3 children whose WPW persisted had short and widely spaced attacks (60 p. 100). This study confirms the high rate of spontaneous disappearance of WPW and the excellent prognosis of this syndrome in the absence of heart disease.