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Biomedical subjects

R Donner

Publications and source records attributed to R Donner.

At least 19 recordsLinked to original sources
PubMed1988

Alterations in left ventricular geometry, wall stress, and ejection performance after correction of congenital aortic stenosis.

Children with congenital aortic stenosis have "excessive" left ventricular hypertrophy with reduced resting systolic wall stress that allows for supernormal ejection performance. If aortic stenosis is uncorrected, this pattern persists until adulthood. The effect of removing the aortic pressure gradient on left ventricular hypertrophy and wall stress in children with congenital aortic stenosis is unknown. To test the hypothesis that removal of the stimulus for hypertrophy by aortic valve replacement or repair would normalize left ventricular mass and wall stress, we measured left ventricular ejection performance, wall stress, and contractile function in seven patients at cardiac catheterization before and 36 +/- 7 months after surgical correction of congenital aortic stenosis. After aortic valve replacement or repair, the aortic valve gradient fell from 87 +/- 12 to 7 +/- 4 mm Hg, and peak left ventricular pressure fell from 187 +/- 14 to 128 +/- 8 mm Hg. Left ventricular ejection fraction decreased postoperatively from 86 +/- 4% to 74 +/- 4% (p less than 0.001), whereas velocity of circumferential fiber shortening decreased from 2.15 +/- 0.15 to 1.6 +/- 0.11 (p less than 0.002). Left ventricular mass remained unchanged preoperatively (121 +/- 14 g/m2) and postoperatively (121 +/- 16 g/m2), but wall thickness (h) decreased in relation to ventricular radius (r) (h/r = 0.55 +/- 0.05 preoperatively, 0.36 +/- 0.02 postoperatively; p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗
PubMed1985

Left ventricular wall stress and function in childhood coarctation of the aorta.

Unlike most adults with compensated pressure overload of the left ventricle, children with moderate to severe aortic stenosis exhibit pronounced left ventricular muscle hypertrophy, enhanced ejection performance and diminished wall stress. To determine whether these findings are present in other forms of left ventricular pressure overload in children, left ventricular mechanics were studied by catheterization in 14 children with coarctation of the aorta (average peak gradient 39 +/- 17 mm Hg) and in 10 normal children. Ejection fraction and mean velocity of circumferential fiber shortening in the coarctation group (0.74 +/- 0.09 and 1.71 +/- 0.43 circumferences/s, respectively) were significantly higher than in normal subjects (0.65 +/- 0.05 and 1.27 +/- 0.26 circumferences/s, respectively) (p = 0.008), but the ranges for both groups overlapped. End-systolic stress in children with coarctation (77 +/- 20 dynes X 10(3)/cm2) was less than in normal children (121 +/- 24 dynes X 10(3)/cm2) (p less than 0.001), again with overlap of the ranges for both groups. The ratio of end-systolic stress to end-systolic volume index, an estimate of contractile function, was similar in both groups. Relations between severity of obstruction (left ventricular peak systolic pressure, coarctation gradient) and end-systolic stress and between stress and ejection performance were present within the coarctation group. Comparison of these data with those found in children with moderate to severe aortic stenosis shows a similar but less pronounced response to pressure overload due to coarctation of the aorta.

Adolescent↗
PubMed1985

Variant angina in an 11 year old boy.

Variant angina is a syndrome in which ischemic cardiac pain occurs with ST segment elevation. The syndrome is due at least in part to coronary vasospasm. Although well documented in adults, there are no known reports of this syndrome in children. The clinical, electrocardiographic and echocardiographic findings in an 11 year old boy with variant angina are reported.

Age Factors↗
PubMed1984

Maximal exercise in children with aortic regurgitation: an adjunct to noninvasive assessment of disease severity.

Twenty-five asymptomatic children with chronic aortic regurgitation were evaluated by graded bicycle exercise testing and standard resting M-mode echocardiogram. These results were compared to those of 35 normal controls matched for age and body surface area. Twenty-one patients underwent cardiac catheterization to rule out associated lesions. Patients fell into two groups based upon the left ventricular end-diastolic volume per body surface area (LVEDVI): group I (n = 10) had LVEDVI less than or equal to 2 SD from the mean of normal; group II (n = 15) had LVEDVI greater than or equal to 4 SD from the mean of normal. All had normal shortening fraction and velocity of circumferential fiber shortening. At maximal exercise, patients in group I were found to have no significant differences from normals in maximal workload, total work, percent maximal oxygen consumption, heart rate, blood pressure, or ST segment depression. However, patients in group II had blunted mean maximal exercise heart rate (p less than 0.001), systolic hypertension (p less than 0.05), and increased frequency and maximal amplitude of ST depression (p less than 0.01, p less than 0.001, respectively) compared to normal controls. Within group II the mean maximal amplitude of ST depression was significantly related to increasing LVEDVI (r = 0.53, p less than 0.05). The mean maximal exercise heart rate, systolic blood pressure, and maximal amplitude of ST segment depression were significantly related to LVEDVI for patient groups and normal controls together (r = -0.384, p less than 0.01; r = 0.28, p less than 0.05; r = 0.70, p less than 0.001, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Improved prediction of peak left ventricular pressure by echocardiography in children with aortic stenosis.

Prediction of peak left ventricular pressure by echocardiography in children with aortic stenosis assumes that wall stress is normal. The recent finding that stress is subnormal in many children with aortic stenosis and elevated ejection performance requires reevaluation of this noninvasive technique. By using M-mode echocardiography, left ventricular end-diastolic dimension and wall thickness and left ventricular shortening fraction were measured in 27 children with aortic stenosis undergoing left ventricular pressure measurement by cardiac catheterization. Similar echocardiographic measurements and systolic blood pressure determinations by the cuff method were obtained from 29 normal children. Peak circumferential wall stress and shortening fraction were calculated from the echocardiographic and pressure data. It was found that stress was inversely proportional to shortening fraction for all patients with aortic stenosis (p less than 0.001, r = -0.86). In a subgroup of patients with a shortening fraction of less than 0.40, stress was 262 +/- 20 mm Hg, similar to 280 +/- 30 mm Hg in the normal group but greater than 205 +/- 27 mm Hg in patients with a shortening fraction of 0.40 or greater (p less than 0.001). In patients with aortic stenosis, the ratio of left ventricular end-diastolic wall thickness to cavity dimension predicted peak left ventricular pressure moderately well (r = 0.83, standard error of the estimate [SEE] = 23). The stress-shortening fraction relation was used to estimate stress and correct this ratio in patients with diminished stress and a shortening fraction greater than or equal to 0.40. This yielded a significantly improved correlation (r = 0.93, SEE = 15, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

Left ventricular wall stress in compensated aortic stenosis in children.

It is known that children with aortic stenosis (AS) frequently have supernormal indexes of left ventricular (LV) pump function and remain compensated for many years. Factors causing this increase in pump performance have not been elucidated. A study was done on LV mechanics in 11 children with AS (aortic valve area 0.5 +/- 0.3 cm2/m2) and 10 normal subjects. The ejection fraction in the AS group (0.88 +/- 0.08) was significantly higher than in normal subjects (0.64 +/- 0.08, p less than 0.001). The mean velocity of fiber shortening was also higher in AS patients (1.80 +/- 0.35 circ/s) than in normal subjects (1.22 +/- 0.21 circ/s, p less than 0.001). The end-systolic volume index in patients with AS (9 +/- 8 ml/m2) was much lower than in normal subjects (27 +/- 8 ml/m2). LV mass in patients with AS was 180 +/- 58 g/m2 compared with 96 +/- 9 in normal subjects. LV wall stress was reduced throughout the cardiac cycle in patients with AS. Peak stress in patients with AS was 238 +/- 51 dynes/cm2 X 10(3) versus 439 +/- 85 in normal subjects. The end-systolic stress-end-systolic volume index ratio, an indicator of contractile state, was not elevated in patients with AS. It is suggested that diminished wall stress in concert with normal contractile function permits the supernormal pump function seen at rest in children with AS.

Adolescent↗
PubMed1982

Histologic distinction between malignant mesothelioma, benign pleural lesion and carcinoma metastasis. Evaluation of the application of morphometry combined with histochemistry and immunostaining.

Thirty men and 7 women with malignant mesothelioma seen at the Free University Hospital from 1st January 1960 until 1st July 1981 were reviewed. The histological, histochemical and morphometrical findings are reported. These findings are compared with 25 cases of pleural metastatic carcinoma and 25 cases of reactive pleural lesions. Fourty-nine percent of malignant mesotheliomas produced hyaluronic acid, however all cases of pleural metastatic carcinomas failed to produce this substance. All cases of malignant mesothelioma were D-PAS negative while 15 cases of pleural metastatic carcinoma showed reactivity to D-PAS. All cases of malignant mesothelioma and 9 cases of metastases were CEA negative. To distinguish malignant mesothelioma from metastases it is advisable to perform the D-PAS staining first. If it is negative mesothelioma can be confirmed by showing hyaluronic acid activity. A positive CEA staining rules out mesothelioma. In our study it was shown that with these methods 18 of 37 mesotheliomas could be identified with certainty, and 22 of the 25 carcinoma metastases. Morphometrically the malignant mesotheliomas could not be distinguished from the metastases, however the reactive pleural lesions had smaller nuclei than the malignant cells with mean values below 30 mu2. In the malignant cases these values had a range from 36 to 101 mu2. In distinguishing between reactive pleural lesions and malignant mesothelioma the production of hyaluronic acid points to the malignant character of the lesion. Thus histochemistry and immunostaining are important in the distinction of malignant mesothelioma from metastases, while the value of morphometry lies mainly in the seperation of reactive lesions from malignant mesothelioma.

Aged↗
PubMed1982

Palliative repair of transposition of the great arteries with criss-cross heart: ventricular septal defect and hypoplastic right (systemic) ventricle.

Four cases of palliative Mustard or Senning repair for transposition of the great arteries (TGA) with ventricular septal defect (VSD), hypoplastic right ventricle, and superior-inferior ventricular configuration are presented. The palliative Mustard procedure-a Mustard repair without VSD closure-is usually reserved for patients with pulmonary vascular obstructive disease (PVOD). In such cases, VSD closure would result in left ventricular failure. Each of our four patients had normal or only slightly elevated pulmonary resistance (1.0 to 5.2 Wood units). However, in each case a hypoplastic right ventricle precluded VSD closure. All four patients had transposition-like hemodynamics with unfavorable streaming to the great arteries, despite the fact that two patients had a levo arterial configuration. In each case, the ventricular relationship included a hypoplastic, superior right ventricle with a horizontal ventricular septum-the so-called "upstairs-downstairs" or "superior-inferior" heart. All patients had previous balloon atrial septostomy or open septectomy to improve atrial mixing. Two patients had previous pulmonary artery banding because of increased pulmonary flow. All four patients remain survivors of the palliative Mustard or Senning repair, which was performed at 10 months, 5 1/2, 12, and 16 years. In each case, there was a marked improvement of symptomatology with a decrease of hemoglobin (mean 21.1 gm/dl preoperatively to 15.3 gm/dl postoperatively) and an increase of arterial oxygen saturation (mean 78 vol % preoperatively to 93 vol % postoperatively). This is the first palliative Mustard or Senning repairs in patients with TGA, VSD, and hypoplastic right ventricle without PVOD. The procedure produces gratifying palliation for these patients.

Adolescent↗
PubMed1981

Hyperplasia of palmar plates and macrodactyly in a young child.

A case is reported of a young girl who presented with macrodactyly of the right middle finger and tumour masses on the palmar side of both interphalangeal joints. The lesions were fibrocartilaginous and appeared to be hyperplastic palmar plates. The macrodactyly and the hyperplasia of the palmar plates were attributed to trauma.

Amputation, Surgical↗
PubMed1980

[Annoyance and loudness measurements in auditory fatigue and recovery under different sound exposures].

In the course of two experimental studies the individual evaluations of noise annoyance during sound exposure were compared with the experimental auditory fatigue (TTS) and the recovery functions. In both studies, in fourteen young men with normal hearing capacity, a temporary threshold shift was built up and then the subjects were submitted during the recovery period to different second-noise levels (narrow band noise and white noise). The loudness estimations and the evaluations of noise annoyance were scaled at the same points as TTS was measured. The poststimulatory recovery of hearing was significantly delayed, even at noise levels of 65 and 75 db. The evaluations of loudness and noise annoyance corresponded well with the recovery of hearing. In the first experiment, the mean values of noise annoyance ratings increased after 16 min of the second noise exposure, in spite of a further decrement of auditory fatigue. In the second experiment, the mean values of noise annoyance ratings remained almost unchanged during the secondary noise exposure. Regarding individual evaluations, however, the noise annoyance ratings of half of the subjects increased whereas the other half decreased. These results are interpreted as a habituation respectively a sensitization process.

Acoustic Stimulation↗
PubMed1980

Juxtacortical osteogenic sarcoma of the jaws. Review of the literature and report of a case.

The juxtacortical osteogenic sarcoma is a rate tumor, especially in the jaws. Until now, only six cases have been reported. Before describing an additional case in the mandible, it was deemed appropriate to review the literature on juxtacortical osteogenic sarcoma in extracraniofacial locations as well. The data on juxtacortical osteogenic sarcomas of the long bones and those of the jaws are discussed.

Adolescent↗
PubMed1980

Development of renal carcinoma in a patient with polycystic kidneys undergoing chronic haemodialysis.

A 67-year-old woman died after 4 years of treatment by haemodialysis. End-stage renal failure was caused by polycystic kidney disease. Malignancy was suspected in the last 6 months of treatment because of impressive weight loss and a suspect liver-scan. Macroscopic haematuria in the first period of treatment was noted only once. Necropsy revealed renal carcinoma of the right polycystic kidney and tumour metastases in various organs. The problem of development of renal carcinoma in polycystic kidney disease in the light of the increased incidence of malignancy during chronic renal failure is discussed.

Female↗