Comparison of the cardiac output and stroke volume response to upright exercise in children with valvular and subvalvular aortic stenosis.
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Cardiac output and stroke volume were evaluated in 17 children (mean age 11.5 +/- 3 years) with discrete, membranous subvalvular (Group I, n = 7) and valvular (Group II, n = 10) aortic stenosis during submaximal and maximal (greater than 75% predicted maximal oxygen consumption) upright cycle ergometry. Patients with valvular aortic stenosis were further subdivided on the basis of their aortic valve gradient at rest determined by cardiac catheterization (Group IIA, gradient less than 40 mm Hg; Group IIB, gradient greater than or equal to 40 mm Hg). These patients were matched with 17 control subjects on the basis of age, sex, height and intensity of exercise during maximal exertion. Cardiac and stroke indexes were determined by the acetylene rebreathing method at each exercise level. Stroke volume index in Group I was significantly greater at rest when compared with that in control subjects (69 +/- 13 versus 53 +/- 11 ml/m2, alpha = 0.01, p less than 0.05) and that in patients in Group II (69 +/- 13 versus 47 +/- 12 ml/m2, alpha = 0.01, p less than 0.05). Patients with subvalvular aortic stenosis were unable to increase their stroke volume index from rest to submaximal exercise and also decreased their stroke volume index at maximal exercise levels. In contrast, patients with mild valvular aortic stenosis (Group IIA) displayed a normal exercise response. Patients with severe valvular aortic stenosis (Group IIB) had a blunted stroke volume response at rest and at each level of exercise, as well as signs of myocardial ischemia (ST segment depression) during maximal exercise.(ABSTRACT TRUNCATED AT 250 WORDS) (+info)
Left ventricular outflow tract obstruction due to anomalous mitral valve: successful mitral valve replacement in a four month old infant.
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A four month old infant was investigated for heart failure was found to have mitral incompetence and severe subvalvar aortic stenosis. The left ventricular outflow tract obstruction was found to be due to an anatomically anomalous mitral valve. The obstruction could only be relieved by removal of the mitral valve and its replacement with a St Jude's prosthesis. Two years after operation the child is fit and active. There have been no difficulties with anticoagulant treatment. (+info)
Discrete sub-aortic stenosis and ventricular septal defect.
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We present details of 15 children, aged 3 months to 11 years, with discrete sub-aortic stenosis and ventricular septal defect. We emphasise a high index of clinical suspicion and echocardiography as the best means of diagnosing this dangerous combination. Physical signs were those of ventricular septal defect in all patients, with auscultatory evidence of additional sub-aortic stenosis in only one. Five patients had a short early diastolic murmur of mild aortic incompetence. The electrocardiograph showed isolated left ventricular hypertrophy in eight patients. Cardiac catheterisation and angiography identified the ventricular septal defect in all cases but detected the sub-aortic stenosis in only eight. Cross sectional echocardiography showed both lesions in all 11 patients to whom it was available. (+info)
Long-term propranolol therapy in muscular subaortic stenosis.
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Twenty-one patients with muscular subaortic stenosis were treated with oral propranolol for periods of 6 to 34 months for a total of 42.5 patient years. The average follow-up was 2 years. Four patients with latent obstruction became asymptomatic on propranolol therapy. Of the 17 patients with resting obstruction, 7 improved, 2 were unchanged, 5 deteriorated, and 2 died during the period of treatment. The 7 patients with resting obstruction who are still improved on propranolol have had relatively short periods of treatment (average 15 months), and none experienced the degree of improvement that occurred in the patients with latent obstruction. This study indicates that propranolol is most effective in patients with muscular subaortic stenosis who have latent obstruction. It is of limited value in patients with resting obstruction because the benefit of propranolol therapy in the majority of these patients is eventually overtaken by progression in the disease. (+info)
Subendocardial ischaemia in patients with discrete subvalvar aortic stenosis.
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The evidence for subendocardial ischaemia was studied in 12 patients with discrete subvalvar aortic stenosis. Symptomatology, electrocardiographic criteria, and pressure difference across the left ventricular outflow tract were compared with the subendocardial flow index (diastolic pressure time index systolic pressure time index). All symptomatic patients had a large pressure difference and abnormal index, but 4 asymptomatic patients had pressure differences greater than 60 mmHg and a low index. One of these 4 patients had a normal resting electrocardiogram. In patients with borderline accepted indications for surgery, calculation of the subendocardial flow index may be an additional useful variable in the timing of surgery. (+info)
Double outlet right ventricle with subvalvular aortic stenosis.
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A case of double outlet right ventricle had progressive muscular subvalvular aortic stenosis unrelated to the ventricular septal defect. Ventricular systolic pressures were identical and higher than aortic, and the gradient was within the right ventricle. Selective angiocardiography showed a hypertrophied subaortic conus obstructing the right ventricular outlet. Serial haemodynamic and angiographic studies revealed progression of the subaortic stenosis which may have been related to an earlier pulmonary artery banding operation. Distal conal hypertrophy is postulated as the cause of the obstruction. (+info)
Discrete subaortic stenosis.
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Data concerning 17 consecutive patients with discrete subaortic stenosis are recorded. Twelve patients underwent operative resection of the obstructing lesion. Of these all except one were symptomatic and all had electrocardiographic evidence of left ventricular hypertrophy or left ventricular hypertrophy with strain. They had a peak resting systolic left ventricular outflow tract gradient of greater than 50 mmHg as predicted from the combined cuff measurement of systolic blood pressure and the echocardiographically estimated left ventricular systolic pressure and/or as determined by cardiac catheterisation. The outflow tract gradient as predicted from M-mode echocardiography and peak systolic pressure showed close correlation with that measured at cardiac catheterisation or operation. During the postoperative follow-up from one month to 11 years, of 11 patients, one patient required a further operation for recurrence of the obstruction four years after the initial operation. All patients are now asymptomatic. Five patients have not had an operation. The left ventricular outflow tract gradient as assessed at the time of cardiac catheterisation was greater than 50 mmHg. One patient has been lost to follow-up. The remaining four have been followed from four to eight years and have remained asymptomatic and the electrocardiograms have remained unchanged. Careful follow-up of all patients is essential with continuing clinical assessment, electrocardiograms, M-mode and two-dimensional echocardiograms, and if necessary cardiac catheterisation. Prophylaxis against bacterial endocarditis is also essential. (+info)
The management of congenital aortic stenosis.
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The progress of 128 patients with congenital aortic stenosis has been followed from one to 28 (mean 14) years. Fifty-eight underwent cardiac catheterisation, and 46 (36% of the total) required surgical treatment. Of these, 42 were under 20 years old. Additional cardiac lesions were noted in five. Infective endocarditis was encountered in four. The onset of symptoms or increasing evidence of left ventricular hypertrophy on the electrocardiogram were the principal indications for catheterisation. Two-dimensional echocardiography is now important in this context. There were four deaths in the 46 surgically treated patients; three of these were early and the fourth was a late death three years after operation due to a massive cerebral embolus complicating infective endocarditis. The 42 survivors of operation and the 82 unoperated patients have remained under long-term supervision. Further surgery was necessary in 12 of the 42 surgically treated patients--valve replacement in seven of them two to eight years after valvotomy, replacement of a calcified xenograft valve in three, and repeat operation in two because of recurrence of subvalvar obstruction. Aortic stenosis is not a benign condition in childhood and adolescence. Close supervision is necessary and when any deterioration is detected further investigation as a prelude to probable surgery is mandatory. This should not be embarked on lightly in childhood unless there are pressing indications, particularly in view of the serious disadvantages of valve replacement in childhood. (+info)