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Biomedical subjects

R Mocellin

Publications and source records attributed to R Mocellin.

At least 55 records · Page 3Linked to original sources
PubMed1977

[Functional studies in children and adolescents with congenital complete heart block (author's transl)].

In 5 children and adolescents with congenital complete heart block functional studies were performed at rest and during submaximal and maximal work load. With reference to height standards the mean values of aerobic capacity and maximal cardiac output were reduced to 86% and 81%, respectively, whereas stroke volume during maximal oxygen uptake was elevated to 150%. Ventricular rate increased from a mean value of 50 min-1 at rest to a mean maximal value of 112 min-1 by the factor 2.2, atrial rate from 84 min-1 at rest by the factor 2.3 to 192 min-1 at maximum. The mean value of maximal arteriovenous oxygen difference was 14.5 ml/100 ml, the mixed venous oxygen content at maximal oxygen uptake was 4.3 ml/100 ml. The results show that compensation of the reduced ventricular rate not only at rest but also during work was mainly achieved by the increase of stroke volume. The compensatory elevation of stroke volume was, within certain limits, the greater, the more maximal ventricular rate was reduced. As an additional but considerably less effective compensatory mechanism the arteriovenous difference could be evaluated, whose maximal value was about 10% higher than normal.

Adolescent↗
PubMed1977

[Pulmonary atresia with ventricular septal defect. Follow up and surgical results from 1963 to 1976 and diagnostic measures with special reference to large systemic-pulmonary collaterals (author's transl)].

Clinical course, surgical results, and diagnostic procedures of 76 patients with pulmonary atresia and ventricular septal defect between 1963 and 1976 were reviewed. 50 patients had bilateral intrapericardial pulmonary arteries with confluence (group A) and 4 patients had a unilateral intrapericardial pulmonary artery (group B). In 22 patients intrapericardial pulmonary arteries could not be demonstrated (group C). 11 of 20 patients in group A with no surgical intervention died at a mean age of 1.4 years, 9 of 30 children died after operation at a mean age of 3.4 years. 2 of 6 patients died after Rastelli procedure. The additive mortality of the palliative procedures in this group was 22%. There are no deaths after the two Rastelli procedures in group B. 81 collaterals originating from descending aorta and 8 from subclavian artery or brachiocephalic trunc which supplied the lung were outlined. 20 collaterals from descending aorta and 4 from subclavian arteries had connections with the intrapericardial pulmonary arteries. In 17 of the former 20 stenoses were demonstrated. Stenoses were also present in 37 of 61 collaterals without connections with the intrapericardial pulmonary arteries in patients belonging to group A, B and C.

Adolescent↗
PubMed1977

[Postoperative cardiopulmonary function studies in children and adolescents with pulmonary valvular stenosis (author's transl)].

Cardiopulmonary function studies at rest and during submaximal and maximal exercise were performed in 20 children and adolescents who had undergone valvotomy of a pulmonary valvular stenosis. Maximal oxygen uptake of the patients was 90%, stroke volume 95% of expected values. There was a strong correlation between stroke volume and maximal oxygen uptake. Mean right ventricular systolic pressure at rest was 39 mm Hg and increased to 60 mm Hg at a submaximal load corresponding to 1 1/2 Watt/kg body weight. There was no correlation between right ventricular systolic pressure on the one hand and maximal oxygen uptake, stroke volume and pulmonry valve resistance, on the other hand. It is concluded, that the importance of maximal oxygen uptake as the equivalent of cardiovascular performance capacity and of stroke volume alone as a main parameter of cardiac function may not be overestimated regarding their value in the assessment of the surgical result. A reoperation must be considered when a distinctly elevated right ventricular pressure at rest shows an additional overproportional increase at exercise in the presence of a decreasing stroke volume. This was the case in 3 of our 20 patients.

Adolescent↗
PubMed1976

[On the validity of W170 as a measure of physical performance capacity in the assessment of children with heart disease (author's transl)].

W170, i.e., the work rate at a heart frequency of 170 beats per minute, and maximal oxygen uptake were determined in one performance in 20 boys and 23 girls from 6 to 16 years of age on a bicycle ergometer. The results were related to normal values according to age and height. In different age and sex groups correlation coefficients between W170 and maximal oxygen uptake amounted to values between 0.36 and 0.66. Accordingly only 13--44% of the variance of maximal oxygen uptake were covered by W170. The imperfect conformity between indirectly and directly measured cardiovascular performance capacity was due to the considerable variability of the maximal heart rate. Accordingly we found correlation coefficients from 0.28 to 0.69 for the relations between maximal heart rate on the one hand and the difference between percentage values of maximal oxygen uptake and W170 on the other hand. That means that the error of an indirect determination by means of the W170 is mostly higher, the more the maximal heart rate differs from the mean value of the group. The estimation of cardiovascular performance capacity by means of the W170 yielded higher relative values than by means of maximal oxygen uptake. The reason for this is probably that in our present investigations we used another type of ergometer than that we had used earlier for determination of normal values of W170, to which we referred in our present investigations. We suggest that the different gyrating mass of different types of ergometers in spite of identical calibration may influence the results via a different mechanical efficiency.

Adolescent↗
PubMed1976

[The natural course of great ventricular septal defect with pulmonary hypertension in childhood].

The development of pulmonary vascular resistance was studied in 33 children with large ventricular septal defects, whose first heart catheterization had been accomplished during the first year of life and who had been recatheterized at least once before surgery had been performed. In 6 children infundibular stenosis developed, which was already seen during the first investigation in 5 cases. The other 27 patients were divided into 4 groups according to the left to right shunt ( less than 60%' greater than 59%) and to the pulmonary arterial pressure (PPsyst: PSsyst less than 80 : 100; PPsyst: PSsyst greater than 79 : 100). The results show that secondary elevatin of pulmonary vascular resistance after an initial fall is a frequent phenomenon, but that in some cases pulmonary vascular resistance is never low. In some other cases pulmonary vascular resistance does not rise again after the initial fall inspite of a high left to right shunt, sporadically because the defect has become smaller. The results are not in full agreement with the concept of Hoffman and Rudolph, who generally postulate an initial fall of pulmonary vascular resistance and who concede a later elevation of pulmonary vascular resistance only as consequence of a secondary re-increase. The concept of Bloomfield, on the other hand, seems suitable to interprete the different patterns.

Age Factors↗
PubMed1976

Exercise performance in children and adolescents after surgical repair of tetralogy of Fallot.

Cardiopulmonary function studies at rest and during submaximal and maximal exercise were performed in 21 children and adolescents who had undergone surgical correction of tetralogy of Fallot. Maximal oxygen uptake of the patients was 84.6% of healthy peers matched for age and height. The reduced aerobic capacity can mainly be attributed to a reduction in stroke volume. In the presence of a reduced stroke volume normal cardiac output during submaximal exercise was achieved and maintained by an increase in heart rate. During maximal exercise, however, the heart rate did not exceed that of the healthy controls and the results for the children in this series are about 20% higher than those reported in the literature for adults who had undergone surgical repair of a tetralogy. Persistent impairment of cardiac function in patients with tetralogy of Fallot who have undergone corrective surgery may represent a residual outflow tract obstruction in the right ventricle, impaired function of the left ventricle or the result of restricted physical activity.

Adolescent↗
PubMed1975

[Oxygen consumption in infants and children with congenital heart defects].

Resting oxygen uptake was determined by a diaferometer in 90 children with congenital heart disease and in 39 children without cardiac defects, both groups ranging in age from 1 month to 15 years. The children with cardiac defects were classified according to the kind of the defect. The values of all children were related to body surface area and in every case compared with standards of basal metabolic rate of Karlberg and Fleisch. Although there was a tendency to higher values of resting oxygen uptake in children with cardiac defects, a statistically definite difference to the standard values could not be established. The possibly influencing factors of oxygen uptake in children with cardiac defects, as weight reduction, sedation, heart dynamics and oxygen cost of breathing are discussed regarding the literature.

Adolescent↗
PubMed1975

Late banding operation in children with ventricular septal defect and pulmonary arterial hypertension.

Since 1960 31 children, 2-10 years old, with large ventricular septal defects and pulmonary arterial hypertension, underwent pulmonary artery banding in Munich. 22 of these children were recatheterized 3-5 years after the operation. Only 8 of these children were shown to have a definite decrease in pressure distal to the band, and in only 2 of these children a reduction of pulmonary vascular resistance to values at the upper limit of normal could be shown. In the remaining children either little or no alteration and rarely even a definite increase of pulmonary vascular resistance was found. There was only a poor correlation between pressure changes and resistance changes. During preoperative catheterization oxygen breathing was shown to produce a more than 50% reduction in the pulmonary arterial pressure in 8 cases. Of these, only 5 showed a decrease of pulmonary vascular resistance after pulmonary artery banding. This decrease, however, was relatively small.

Child↗
PubMed1975

[Functional studies in rest and during exertion in children and adolescents with ventricular septal defects and pulmonary hypertension].

7 children from 7-15 years of age, who had a large VSD with pulmonary arterial hypertension, were investigated on a bicycle ergometer during stepwise increasing load. In 5 cases a pulmonary artery banding had been performed earlier in spite of distinctly increased pulmonary vascular resistance. In two cases with Eisenmenger-syndrome no operative measures had been attempted. The measurements, which were carried out at rest and during two submaximal loads, comprised beside determination of oxygen uptake and heart frequency also the arteriovenous oxygen difference as well as mean arterial pressure in the pulmonary and the systemic circuit so that flow and resistance could be calculated for both circuits. During exercise a linear increase of flow in the pulmonary circuit was achieved in all cases, accompanied by a distinct rise of the mean pulmonary arterial pressure. The pulmonary vascular resistance stayed, however, generally constant. Systemic vascular resistance, on the contrary, decreased to about one third of the resting values so that the ratio of pulmonary arterial to systemic vascular resistance increased considerably. The result was a progressive increase of the right to left shunt during exercise, and in 3 cases with predominant left to right shunt at rest in spite of the band, a reversed shunt resulted, partially due to the effectiveness of the band, but substantially brought about by the undiminished high pulmonary vascular resistance. The results show that ergometric investigations in children with pulmonary arterial hypertension may contribute to clarify the indication for surgery, but they also confirm that generally a final operation is not possible in children whose banding-operation has been performed at the age of more than 2 years.

Adolescent↗