Twenty-five cases of left ventricular inflow obstruction in children aged 4 months to 11 years were investigated by two-dimensional echocardiography and cineangiography. The results of 2D echo were compared with the operative appearances in 15 cases and the pathological findings in three cases. This series included 5 cases of cor triatrium and 20 of congenital mitral stenosis, 3 of which were associated with a supramitral ring. Abnormalities of the mitral papillary muscles were the main cause of congenital mitral stenosis in this series (12 cases); there were 6 cases of single papillary muscle and 6 cases with two closely situated or fused papillary muscles. These abnormalities of the mitral papillary muscles were demonstrated on the transverse left ventricular views obtained from the parasternal or subcostal regions. All the papillary muscle abnormalities diagnosed by 2D echo were confirmed at autopsy or surgery. Cases of mitral stenosis due to short and thickened chordae were demonstrated on parasternal long axis views. Hypoplasia of the mitral ring was visualised on long axis or apical views. The supramitral ring was demonstrated on the parasternal long axis or apical four chamber views, as an abnormal echo situated just above the mitral valve in the left atrium. All three cases in this series were correctly diagnosed by 2D echocardiography. Nineteen of the 20 congenital mitral stenoses were associated with other cardiac malformations (14 coarctations of the aorta, 9 aortic stenoses, 4 ventricular septal defects) which were also detected by 2D echocardiography.
Radio-nuclide angiography after surgical correction of tetralogy of Fallot (TOF) allows measurement of the ejection fraction, especially of the right ventricle, under basal conditions and on effort, parameters which are difficult to measure by other non-invasive methods. Twenty-two children with a mean age of 12.6 +/- 6.9 years who had undergone complete correction of TOF at a mean age of 6.7 +/- 3.8 years underwent Technetium 99m blood pool studies at equilibrium. The results were compared with those of a control group of children with a mean age of 10.2 +/- 3.3 years. No first passage studies were performed because the frequency of postoperative pulmonary regurgitation does not allow quantification of the shunt due to a possible residual ventricular septal defect. No significant difference was found between the patients and control subjects at rest: LV ejection fraction (66.7 +/- 11 p. 100 vs 63 +/- 7.7 p. 100), RV ejection fraction (50.3 +/- 7.2 p. 100 vs 54 +/- 14.8 p. 100). The response to effort of the right and left ventricles depends on the type of exercise. The LV ejection fraction increased normally whilst the RV ejection fraction showed a lot of individual variation. Equilibrium radionuclide angiography was also used to calculate the ratio of right to left end diastolic ventricular volumes. This ratio indicates the degree of RV diastolic overload when LV diastolic volumes are normal, which was the case in our series. The study group showed a significant increase in this ratio compared to control subjects (1.94 +/- 0.65 vs 1.2 +/- 0.23). Exercise radionuclide imagery should provide more accurate assessments of the surgical results and prognosis of these children providing standardised protocols are used. These investigations are best performed in patients over 15 years old, so as to avoid the technical difficulties related to small size. Resting studies are possible at all ages.
The authors report the case of a child with a small muscular ventricular septal defect proved by means of right endocardial phonocardio-gram. Lateral views during left ventriculography showed a peculiar tortuous communication within the septum, ressembling a channel. The possible embryologic origin is discussed.
