Rheologic genesis of discrete subvalvular aortic stenosis: a Doppler echocardiographic study.

To determine whether morphologic structures or abnormal flow patterns predispose to pathologic proliferation of subvalvular tissue, 26 patients (mean age 19.8 +/- 10.3 years) were studied greater than or equal to 6 months after operation for isolated discrete subvalvular aortic stenosis. The aortic root diameter and the mitral-aortic separation were measured with sector echocardiography. Flow patterns in the left ventricular outflow tract of these patients and control subjects were evaluated with a color flow mapping system optimized for the detection of turbulence. All control subjects had laminar flow throughout systole in the left ventricular outflow tract. By contrast, turbulence originating well below the site where the shelf had previously been resected was observed in 20 (77%) of the 26 patients. In 16 of these 20 patients turbulence was caused by a ridge, which in 13 patients could be identified as the offshoot of a ventricular band. In four patients the turbulence was caused by malalignment of the muscular and membranous septum, resulting in protrusion of the muscular septum into the outflow tract. Except for the latter four patients, the aortic root diameter was 84 +/- 10% of values predicted by body surface area, with values in six patients falling below the third percentile (p less than 0.01). The mitral-aortic separation was 9.7 +/- 3.5 mm, values in 21 patients falling above the 97th percentile (p less than 0.001). These data support the theory that discrete subvalvular aortic stenosis may be caused by a chronic flow disturbance, preferably in a small and long outflow tract. Left ventricular bands, if reaching the outflow tract, may be a factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiorespiratory exercise testing after venous switch operation in children with complete transposition of the great arteries.

In 14 children who underwent a venous switch operation for complete transposition of the great arteries, exercise testing was performed 3 to 15 years (mean 8) after the operation. Exercise performance capacity was assessed by the determination of the ventilatory threshold during exercise and by the oxygen uptake (VO2) reached at a heart rate of 170 beats/min (VO2,170). The ventilatory threshold was defined as the highest oxygen uptake (VO2) at which the pulmonary ventilation (VE) stops to increase linearly when related to VO2. During exercise above this threshold a disproportionate increase in VE relative to VO2 is observed. The mean ventilatory threshold was significantly lower (p less than 0.01) than the normal mean value and averaged 72 +/- 15%, 67 +/- 15% and 70 +/- 13% of the predicted normal value for children of comparable age, weight and height, respectively. The mean value for VO2,170 also was significantly lower (p less than 0.05) than the normal mean value for children of comparable age, weight and height, and averaged 81 +/- 20%, 81 +/- 18% and 80 +/- 18%, respectively. Compared with normal control subjects of the same sex and age, the ventilatory threshold was surpassed sooner (p less than 0.001) and reached after 2 +/- 1 min instead of the 4 +/- 1 min required by the controls. In nearly half of the patients, a lower than normal (i.e. below the 95% confidence limit) heart rate response to exercise was observed. Theoretically, this could be interpreted as indicating a normal or high physical performance capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Usefulness of echocardiographic assessment of right ventricular and pulmonary trunk size for estimating magnitude of left-to-right shunt in children with atrial septal defect.

M-mode and 2-dimensional echocardiographic studies were performed in 42 patients, aged 1 to 16 years (mean 6), with a secundum or sinus venosus type atrial septal defect (ASD) and normal pulmonary artery pressure. Twenty normal children served as a control group. In patients with ASD the echocardiographic variables were correlated with the magnitude of the left-to-right shunt (Qp/Qs) calculated by the Fick principle. Although M-mode echocardiograms showed increased right ventricular (RV) dimension in 69% of the patients, the correlation between RV dimension index (RV dimension/body surface area) and Qp/Qs was weak (r = 0.49). When RV dimension was related to left ventricular (LV) dimension and expressed by the RV/LV ratio, 90% of the patients were found to have an abnormally large right ventricle. The correlation between the RV/LV ratio and Qp/Qs was fairly good (r = 0.64). In 33 patients (78%), the pulmonary trunk (PT) was adequately visualized and measured on 2-dimensional echocardiograms. The dimension of the PT was related to the aortic root dimension and expressed by the PT dimension/aortic dimension ratio. This ratio was 0.99 +/- 0.06 in normal children and 1.35 +/- 0.23 in patients with ASD (p less than 0.001). The PT/aortic ratio exceeded the upper limit of normal (the normal mean value + 2 standard deviations) in each of the 27 patients with a Qp/Qs of 1.5 or greater. In 5 of the 6 patients with a Qp/Qs of less than 1.5 the PT/aortic ratio was close to 1 and within the normal range. An excellent correlation (r = 0.89) was found between the PT/aortic ratio and Qp/Qs.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term echocardiographic assessment of dilated cardiomyopathy in children.

Left ventricular (LV) dimensions and function were assessed by echocardiography in 22 children with dilated cardiomyopathy. They had survived an initial episode of congestive heart failure in infancy for greater than or equal to 2 years. At the time of echocardiography, when they were 3 to 16 years old, 8 patients (Group 1) still had signs of dilated cardiomyopathy and 14 (Group 2) had lost all roentgenographic and electrocardiographic evidence of heart disease. All 8 patients in Group 1 (average follow-up 4.5 years) had significantly increased LV dimensions. The end-diastolic dimension averaged 144 +/- 18% of the normal value. Fractional LV shortening with systole was significantly reduced and averaged 23 +/- 3%. The E point-septal separation ranged from 7 to 17 mm (mean 12 +/- 4) and was far above the normal limit in all. Of the 14 patients in Group 2, seven (average follow-up 7 years) had normal ventricular dimensions and 7 (average follow-up 10 years) had LV dimensions larger than the upper range of the 95% prediction limit. In 6 of the latter patients the fractional LV shortening with systole was less than or equal to 31% and the E point-septal separation in excess of the upper limit of normal. These findings indicate that about half of the patients who had apparently recovered still had residual lesions as judged from the echocardiogram. In 6 patients in group 1, two-dimensional echo-cardiography allowed the visualization of a thickened endocardium. One of these 6 patients died. The echocardiographic image correlated well with the process of LV endocardial fibroelastosis found at necropsy.

Cardiorespiratory response to exercise in congenital complete atrioventricular block.

In 8 patients aged 8 to 17 years with congenital complete atrioventricular (AV) block, exercise testing was performed on a treadmill. Cardiorespiratory endurance performance was assessed by determination of the ventilatory threshold. The mean value for ventilatory threshold was significantly lower (p less than 0.005) than the normal mean value and averaged 76 +/- 16%, 75 +/- 17% and 75 +/- 16% of the predicted normal value in children of the same sex and comparable age, weight and height, respectively. The ventricular rate at rest varied from 36 to 56 beats/min and increased to a mean value of 106 +/- 25 on exercise. When expressed as a percentage of the normal value, the heart rate was subnormal (below the 95% confidence limit) in all patients, throughout different exercise levels. For the same exercise intensity the oxygen uptake, expressed as ml/min/kg, was significantly lower (p less than 0.02) in patients than in normal individuals. This suggests an inadequate hemodynamic adjustment to the relative exercise bradycardia and a higher than normal anaerobic/aerobic energy supply. Exercise testing was found to be useful in the assessment of congenital AV block, because the resting heart rate did not permit prediction of the relative exercise bradycardia or the degree of exercise intolerance.

Apparent Greig cephalopolysyndactyly and sinus node disease.

We present the clinical findings and follow-up data from birth to 10.5 years in a boy with Greig cephalopolysyndactyly who, in addition, presents sinus node disease ("sick sinus syndrome"). The significance of the concurrence of Greig cephalopolysyndactyly syndrome, an autosomal dominant condition mapped at 7p13, and sinus node disease is discussed.

Evaluation of breath-by-breath measurement of respiratory gas exchange in pediatric exercise testing.

In adults, breath-by-breath analysis has been used for measuring respiratory gas exchange during exercise. The present study evaluates the validity and reproducibility of this method in children. In 21 patients with various types of congenital heart disease, steady state exercise testing was performed on a motor-driven treadmill. Based on simultaneous measurements of VO2, VCO2, VE and R, comparisons were made between the breath-by-breath and Douglas bag methods. No significant differences were found between both methods for any of the variables. In seven other patients the reproducibility of cardiorespiratory variables during exercise was assessed. No significant difference was found for the cardiorespiratory variables during any of the tests and the coefficients of variation were comparable to data obtained in adults. It is concluded that the breath-by-breath method for measuring respiratory values can be applied in children with an acceptable degree of validity and reproducibility.

Infections caused by Kingella kingae: report of four cases and review.

Kingella kingae, formerly known as Moraxella kingae, is a fastidious, non-motile, coccobacillary, fermentative Gram-negative rod that has been chiefly associated with two types of infections in man: bone and joint infections, and endocarditis. We describe four patients with K. kingae infections, one with septicaemia, two with endocarditis, and one with osteoarthritis. The current literature on infections with K. kingae is reviewed.

Results from an international survey of Kawasaki disease in 1979-82.

Kawasaki disease is a febrile illness of unknown etiology affecting mainly children younger than five years, 20% of whom develop coronary artery aneurysms. The disease was first reported in Japan, but case reports have come from several countries; epidemics apparently occur every two to three years. A committee of the International Society and Federation of Cardiology (ISFC) collaborated on an international, retrospective survey in mid-1983 through 1984, asking about Kawasaki disease cases seen in 1979-82 and their outcomes. Responses were received from 53 countries; reports from 20 countries indicated that no cases were seen in the years surveyed. Kawasaki disease did not always follow the Japanese pattern. An indication of 'epidemic' increases was found in some years in some countries. Recognition of Kawasaki disease varies considerably, but further educational efforts are likely to uncover additional cases, and intensive epidemiological efforts would be possible in a number of countries.

Aneurysm of the left atrial appendage.

A 2-year old asymptomatic girl is presented in whom the chest x-ray film led to the discovery of a grossly distorted cardiac shadow. Angiocardiography showed a giant aneurysm originating from the left atrium. At operation an intrapericardial aneurysm of the left atrial appendage, measuring 12 X 4 X 4 cm, was found. It communicated with the left atrium through an orifice measuring 3 cm. The aneurysm was excised.

Total correction of tetralogy of Fallot following palliation.

Fifty three patients with Tetralogy of Fallot were totally corrected following palliation. Intracardiac repair was not adversely influenced by a Blalock Taussig shunt or a Waterston shunt which did not produce kinking of the RPA. The results were less satisfactory after correction following a Potts shunt or a Waterston shunt with kinking at the site of the anastomosis.

[The tetralogy of Fallot: surgical treatment. 145 cases (author's transl)]. / De tetralogie van Fallot: chirurgische behandeling. 145 gevallen

1. The overall operative risk for the palliative procedures for Tetralogy was 3,2% (93 cases). The Blalock-Taussig shunt remains the intervention of choice in older children. The Waterston shunt gives optimal results in the infants under six months of age but on long term the hasard of pulmonary hypertension still exists. 2. Before 1965, the mortality rate for the total repair was 43,7% (16 cases). During the last 8 years, the mortality rate decreased to 5,7% (36 cases). One operative death after total correction with a Potts shunt is not included in this figure. This type of shunt was replaced by the Waterston shunt after 1966, because of the high operative risk total correction and the high frequency of pulmonary hypertension on long term. 3. The long-term results were excellent in 85% of the survivors (mean follow-up of 4,1 years). A pulmonary insufficiency was found on clinical examination in 35% of the cases. This insufficiency was well tolerated by all patients. The long-term consequences, however, are uncertain. 4. It seams rational to proceed to an earlier total correction in these cases when well defined criteria are fullfilled, as the mortality figures of the palliative and corrective procedures have a tendency to reach each other: (3,2 versus 5,7%).

Transient neonatal tricuspid regurgitation: a Doppler echocardiographic study of three cases.

Three patients with normal hearts and no pulmonary abnormality had neonatal tricuspid regurgitation causing cardiorespiratory distress and cyanosis. The signs of tricuspid regurgitation resolved over a few weeks. In the acute phase echocardiography showed gross dilatation of the right atrium and ventricle. The interatrial septum bulged into the left atrium during the whole cardiac cycle. Doppler echocardiography showed clinically significant tricuspid regurgitation, a right to left shunt through the foramen ovale, reduced flow through the pulmonary valve, and in two patients ductal flow into the pulmonary artery. In one patient tricuspid regurgitation was so great that it impeded the opening of the pulmonary valve and produced functional "atresia" of the pulmonary valve. The presence of regurgitant blood flow through the pulmonary valve showed that the "atresia" was functional rather than organic. Doppler echocardiographic study is useful in distinguishing functional neonatal tricuspid regurgitation from structural abnormality of the tricuspid valve.

Atrial reciprocal rhythm and reciprocating tachycardia in Wolff-Parkinson-White syndrome.

In an infant with type A Wolff-Parkinson-White syndrome, atrial reciprocal beats and attacks of reciprocating tachycardia were repeatedly recorded. Their dependence on a prolongation of the P-R interval could be well demonstrated during Wenckebach periods. Because of the normal aspect of the QRS complex during arrhythmia, the short ventriculo-atrial conduction time (0.08 sec), and the vectorial orientation of the secondary P wave, it was concluded that retrograde reactivation of the atria probably took place via the anomalous bundle. The versatility of the conduction through the accessory bundle is shown by the fact that its direction may change from antegrade in one beat to retrograde in the next. The importance of a circus movement in the genesis of some types of tachycardia in the WPW syndrome is discussed.

Sick sinus syndrome in childhood.

The clinical and electrocardiographic findings in five children with the sick sinus syndrome and an otherwise normal heart are described. There were three boys and two girls. Their age at onset of either bradycardia or symptoms ranged from 1 day to 7 years. In one patient, the youngest ever reported with this syndrome, bradycardia was noted before birth. Four children presented with neurological symptoms--attacks of dizziness, fainting spells, or syncope. One boy, treated for epilepsy before the underlying arrhythmia ws diagnosed, died suddenly while playing. One child had near-fatal syncope caused by ventricular tachycardia. Continuous 24-hour electrocardiographic monitoring is the best method of assessing the severity of the condition. Sinus bradycardia, sinuatrial block, and periods of sinus arrest up to 4.8 seconds were recorded. Two patients had associated atrioventricular block and were therefore presumed to have binodal disease. Atrial fibrillation or flutter occurred in three patients. Isolated sick sinus syndrome may be a life-threatening condition in childhood for which, in selected cases, the insertion of a permanent pacemaker is indicated.

Congenital atresia of left coronary ostium.

A two-year-old girl, who presented with congestive heart failure and an extensive anterolateral infarction, was thought to have anomalous origin of the left coronary artery from the pulmonary artery. She improved rapidly and remained symptom free until 13 years of age, when she died suddenly. At necropsy the right coronary artery was found to be normal but in the left aortic sinus a dimple was the only remnant of the left coronary ostium. The proximal segment of the left long term follow-up of a patient with this rare anomaly.