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Biomedical subjects

B Friedli

Publications and source records attributed to B Friedli.

At least 109 records · Page 6Linked to original sources
PubMed1982

Estimation of pulmonary artery pressure by ultrasound. A study comparing simultaneously recorded pulmonary valve echogram and pulmonary arterial pressures.

To determine the most reliable echocardiographic criteria of the pulmonary valve echo in predicting pulmonary artery (PA) pressures or PA resistance, 48 children, aged 6 months to 16 years with congenital (CHD) or rheumatic heart disease (RHD), were studied. During routine heart catheterization, simultaneously recorded PA pressures and one-dimensional PA valve echograms were obtained. Echocardiographic measurements of the e-f and b-c slopes, the "a" dip, right ventricular (RV) and left ventricular (LV) systolic time intervals (STI; PEP = pre-ejection period; ET = ejection time), and their ratios were compared with PA systolic, diastolic, and mean pressures as well as the pulmonary arteriolar resistance (PAR) and the ratio PAR to systemic resistance (SR). The e-f and b-c slope correlated poorly with PA pressures and PAR. RVPEP/RVET ratio gave a good second-degree polynomial correlation with PA diastolic pressure, PAR and PAR/SR in CHD (r = .78, .79, .87). The correlation was better for children with CHD than for those with RHD. This correlation was also more significant than RVPEP/LVPEP, and RVET/LVET. The "a" dip correlated well with the diastolic PA pressure in CHD and RHD (r = .73). A multivariant analysis of the "a" dip and RVSTI ratios slightly improves the correlation coefficient and the prediction rate for PA diastolic pressures, PAR, and resistance ratios in CHD and CHD + RHD.

Adolescent↗
PubMed1982

Mitral valve replacement in children. Comparative study of pre- and postoperative haemodynamics and left ventricular function.

Haemodynamic variables and left ventricular function were studied before and after mitral valve replacement in 44 children age 3 to 17 years (mean 11.9 years). Thirty-nine Starr-Edwards prostheses and five Hancock prostheses were used; postoperative study took place two to six months (mean 3.9 months) after operation. Pulmonary hypertension was present preoperatively in most patients, with mean pulmonary artery pressures of 18 to 75 (mean 46.5 mmHg). Postoperatively there was a pronounced drop in pressure to a mean value of 25.6 mmHg, partially explained by a decrease in pulmonary capillary wedge pressure. Pulmonary arteriolar resistance, however, also decreased conspicuously from an average of 590 dynes s cm-5 m-2 preoperatively to 282 dynes s cm-5 m-2 postoperatively. A return to normal resistance was seen in every case when preoperative resistance did not exceed 650 dynes s cm-5 m-2; above this threshold some degree of pulmonary hypertension often persisted. The residual gradient across the prosthetic valve was slightly higher for the Hancock than for the Starr-Edwards prosthesis (mean 8.7 mmHg, vs mean 6.9 mmHg). The left ventricular end-diastolic volume was much increased before surgery, with a mean value of 190 ml/m2; it decreased conspicuously after operation to 103 ml/m2. The left ventricular ejection fraction ranged from 40% to 76% (mean 57%) before operation; there was no significant change after operation, with values ranging from 40% to 73%. This left ventricular dysfunction is probably the result of myocardial injury caused by a chronic volume overload and the sequelae of rheumatic carditis.

Adolescent↗
PubMed1982

Progressive atrioventricular block after total correction of Fallot's tetralogy, documented by repeat electrophysiological studies.

A case of progressive trifascicular block late after correction of Fallot's tetralogy is reported. Progressive damage to the His bundle and/or its branches over 18 months after surgery was suggested by sequential ECGs and confirmed by repeat electrophysiological studies done 3 and 18 months postoperatively: the H-V interval increased from 55 to 80 ms over this period. With atrial pacing at increasing rates, supra-His 2:1 atrioventricular (AV) block occurred at a rate of 158/min at the first study; at the second study, infra-His block occurred at an atrial pacing rate of only 128/min. A permanent pacemaker was implanted prophylactically. 5 years after surgery, complete heart block occurred without symptoms, the pacemaker having taken over ventricular stimulation.

Bundle of His↗
PubMed1981

[Valve replacement in children: results and long-term follow-up in 171 operated patients].

171 children aged 2-17 years underwent cardiac valve replacement between 1969 and December 1979. Valve lesions were of rheumatic origin in 160 and congenital in 11 cases. Single valve replacement of the mitral valve was performed in 116 cases, of the aortic valve in 18 cases and of the tricuspid valve once. Double valve replacement was done in 33 and triple valve replacement in 2 cases. Starr Edwards prostheses were used in most instances. Operative mortality was 5.9% and late death occurred in 8.7%. The follow-up period ranged from 1-9 years with a mean of 3.6 years. The majority of children have returned to a normal lifestyle and are symptom-free. Only 10% remain digitalized. As in adults, the most frequent complications were thromboembolic. 14 children (11%) had either an embolus or a valve thrombosis with a frequently of 3 per hundred patient-years. Other complications such as endocarditis or paravalvular leak were infrequent, and in most cases treatment was successful. Because of the markedly dilated hearts before operation it was possible in most children to use an adult size prosthesis, especially in the mitral position. Only a few children below 5 years of age received small mitral valve prostheses; they may need to be replaced ultimately by larger ones. Introduction of an embolus-free valve prosthesis for children would be a major advance. Unfortunately, porcine xenografts with their low embolic risk are not suitable for children as they often undergo rapid calcification.

Adolescent↗
PubMed1981

Echocardiographic changes of cardiac structures and LV function in newborns. A comparative study between normally delivered babies and babies born by caesarian section with regional anaesthesia.

Cardiac chamber size and function indices were studied repeatedly over the first months of life in two groups of babies, born either spontaneously or by caesarian section under peridural anaesthesia. For cardiac chamber size, no significant differences were found between the two groups: cardiac structures increased in size as a linear function of age and weight in all babies. Right ventricular systolic time interval ratios, however, were higher at birth in babies born by caesarian section, and dropped more rapidly during the first 24h. The decrease of RV systolic time interval ratios followed a parabolic function for both groups, thus reflecting the physiological decrease of pulmonary vascular resistance after birth. The possible causes of more rapid decrease in pulmonary vascular resistance in babies born by caesarian section is discussed.

Age Factors↗
PubMed1981

[Results of coarctectomy in newborn and young infants].

Twenty infants underwent coarctectomy between 1972 and 1979, 12 were less than one month old at surgery. One infant died after the procedure (5% mortality). Seven underwent open heart surgery later in the first year of life for associated intracardiac defects; there were 3 early and one late death. Of the 15 survivors, 12 have been followed up for 6 months to 6 years (mean 3 years). All are actually asymptomatic. Arterial blood pressure is slightly higher in the leg than in the arm in 8 patients (as in normal children), equal in leg and arm in 2 and lower in the leg than in the arm in 2 (recoarctation). Postoperative catheterization was done in six patients. A pressure gradient across the anastomotic site was confirmed in two (32 and 28 mm Hg). In the other four, no pressure gradient was found, and the site of the anastomosis was hardly or not at all detectable on the angiogram. Coarctectomy in newborns and infants now carries a low operative mortality. With proper operative technique, normal growth of the anastomotic site is usually obtained.

Aortic Coarctation↗
PubMed1981

Echocardiographic growth patterns of intracardiac dimensions and determination of function indices during the first year of life.

Cardiac dimensions and left and right ventricular function indices were studied consecutively in 53 healthy newborn babies throughout their first year of life. Cardiac dimensions, except right ventricular (RV) dimension, increase linearly with age, weight and body surface area, the relation being best described as a linear function of BSA. Left ventricular function indices do no change significantly during the first year of life. Right ventricular systolic time interval ratio (RVPEP/RVET) is high at birth, but declines rapidly during the first hours and days. This change is best described as a parabolic function and is an indicator of the physiological fall of pulmonary vascular resistances.

Anthropometry↗
PubMed1980

Growth patterns of cardiac structures and changes in systolic time intervals in the newborn and infant. A longitudinal echocardiographic study.

A longitudinal study was undertaken in 21 newborns to determine cardiac growth pattern by echocardiography over the course of the first year of life. Most cardiac structures increased in size as a linear function of age and weight; however, the right ventricular end-diastolic diameter remained unchanged so that the RV/LV ratio decreased as a parabolic function of age. Left and right ventricular systolic time intervals (RVSTI, LVSTI) after birth were also studied. The ratio of left ventricular preejection period (LVPEP) to left ventricular ejection time (LVET) decreased markedly immediately after birth and subsequently remained at a constant mean value (0.30 +/- 0.04) for the rest of the study period. Right ventricular systolic time interval ratios (RVPEP/RVET) decreased rapidly and significantly during the first day of life (from a mean value of 0.39 +/- 0.08 in the first 24 hours to 0.28 +/- 0.05 on the 6th day of life). Constant values of 0.24 +/- 0.03 were found from the 3rd month of life onwards. The decrease in RVPEP/RVET in the first days of life followed a parabolic function reflecting the physiological decrease of pulmonary vascular resistance after birth.

Body Weight↗
PubMed1980

Changes in ventricular size and plasma renin activity after cardiac surgery in children.

Plasma renin activity and one-dimensional echocardiographic measurements of the left atrium and left ventricle as well as function indices were studied repeatedly in 20 children with various cardiopathies (ages: 9 months to 15 years) before and after corrective surgery. Nine children had tetralogy of Fallot, four had pulmonary stenosis, four had rheumatic heart disease, two had ventricular septal defect, and one had atrial septal defect. Plasma renin activity was normal preoperatively, but increased significantly immediately after surgery, was still significantly higher on the 12th postoperative day and returned to normal six to eight weeks after surgery. Patients with tetralogy of Fallot and pulmonary stenosis had higher plasma renin activity values than the others. There was a positive correlation between plasma renin activity and postoperative percentage change of the left ventricular dimension. In patients with tetralogy of Fallot and pulmonary stenosis, this meant that plasma renin activity became normal when the preoperatively small left ventricle reached its normal dimension. This adjustment occurred slowly over a period of two months. In rheumatic heart disease and left-to-right shunt lesions, plasma renin activities became normal when the preoperatively dilated left ventricle decreased in size towards normal values; the plasma renin activities of these patients had reached normal levels by the fifth postoperative day. The renin secretion is modulated by various factors: of these, ventricular size and pulmonary venous return seem to be of importance.

Adolescent↗
PubMed1980

[Marchesani's syndrome (spherophakia-brachymorphism)].

The authors report the case of a patient with spherophakia and brachymorphism (Marchesani syndrome). This congenital and familial disorder is characterized by short stature, short limbs and thick extremities, limitation of joint mobility, a peculiar facies and spherophakia (rounded lens). Mentality is normal. The patient presented here, an eleven-year-old girl, had in addition a subvalvular fibromuscular aortic stenosis. A detailed radiological survey of the skeleton demonstrated a disorder of enchondral growth, particularly evident in the extremities, with short and wide diaphyses, thin cortical bone, and relatively discrete epiphyseal deformities. The vertebral bodies were slightly rounded anteriorly, th discs were thinned, and the ribs widened. The spinal canal and the foramen magnum were narrowed, and the lateral processes short and wide. There was thickening of the skull vault. A mucopolysaccharidosis and a mucolipidosis were excluded by biochemical study of skin fibroblasts in culture.

Abnormalities, Multiple↗
PubMed1979

[Tetralogy of Fallot: results of 77 hemodynamic controls after complete correction].

77 patients (representing 91% of all survivors) underwent catheterization within 5 months of surgical repair of tetralogy of Fallot. The data show that residual pulmonary gradient is significantly higher in patients with infundibular and valvular stenoses than in patients with infundibular stenoses only, whereas the method of intracardiac repair (patch) had no influence on residual gradient. Significant pulmonary insufficiency was found almost exclusively when a patch was extended through the pulmonary annulus. Hemodynamic results were excellent in 37% of cases, good in 51%, satisfactory in 3% and unsatisfactory in 9%. Finally, primary intracardiac repair in children below 4 years of age yielded excellent or good results in all cases: this suggests that toal correction should be performed without previous aorto-pulmonary anastomoses in this youngest group of patients.

Cardiopulmonary Bypass↗
PubMed1979

Echocardiographic study of right and left ventricular dimension and left ventricular function in patients with tetralogy of Fallot before and after surgery.

Right and left ventricular dimensions and function were determined by one-dimensional echocardiography in patients with tetralogy of Fallot before and after corrective surgery. Thirty-five children (mean age: 5.9 years) were examined; 5 of them died immediately after operation; 5 had palliative operations only. The remaining 25 had repeat echocardiography 2 to 4 and/or 8 weeks after total correction. Compared with normal values, preoperative left ventricular dimensions were smaller than expected for body surface area (mean = 85.4% +/- 1.9 SEM, range 65 to 105% of normal); 21 values were below the 5th centile. Postoperatively, left ventricular dimensions increased significantly and reached normal values in most cases (mean = 103.2 +/- 2.0% SEM, range 81 to 121%). The main increase took place in the first 4 weeks (P less than 0.001; mean difference 0.7 +/- 0.14 cm). The 5 children who died after operation had smaller left ventricular dimensions than the survivors (P less than 0.01). Left ventricular function was evaluated by measuring mean circumferential fibre shortening, per cent shortening, and ejection fraction; they were normal in most patients and diminished only insignificantly after corrective surgery. Right ventricular dimensions were increased preoperatively but decreased significantly (P less than 0.001) postoperatively. Septal movement was normal in direction and excessive in displacement in most patients before operation; immediately after operation it became flat or showed paradoxical motion. Two months after operation 50 per cent of the children showed a return to normal septal movement. Early appearance of normal septal movement could be related to the presence of significant pulmonary stenosis. It is concluded that a high percentage of patients with tetralogy of Fallot have underdeveloped but normally functioning left ventricles which adapt well to the new postoperative state.

Adolescent↗
PubMed1979

Aneurysm of the left sinus of Valsalva draining into the right atrium.

We report the case of an arteriovenous fistula connecting the aorta to the right atrium, due to a ruptured aneurysm of the left sinus of Valsalva. Clinical, echocardiographic, and angiographic aspects of this unusual lesion are discussed and correlated. Emphasis is put on the diagnostic value of the echocardiogram; a characteristic dense echo parallel to the posterior aortic wall is seen, along with signs of right ventricular volume overload. Combined with the case history and auscultatory finding (a continuous murmur on the right sternal edge), this may lead to the correct diagnosis by noninvasive means.

Adolescent↗
PubMed1979

[Pulmonary valvular subatresia with intact interventricular septum in a newborn infant: role of prostaglandins in the immediate postoperative period].

The case is reported of a newborn with pulmonary valvular subatresia and intact interventricular septum and moderate right ventricular hypoplasia, treated with pulmonary commissurotomy alone. In the immediate postoperative period the ductus arteriosus closed, resulting in deep hypoxia and acidosis. With the infusion of PG E2 the ductus reopened and the baby's condition improved markedly. The ductus was kept open for 20 days, during which time adaptation of the right ventricle must have occurred. Indeed, after definitive spontaneous closure of the ductus, right ventricular output proved sufficient to insure satisfactory pulmonary perfusion.

Ductus Arteriosus↗
PubMed1979

[Conduction of disorders after total correction of Fallot's tetralogy. Electrocardiographic and electrophysiological study].

The conduction defects observed after total correction of Fallot's tetralogy in 133 children, and their association with the long term outcome were studied with comparison of pre and postoperative electrocardiograms and, in 26 cases, His bundle recording. 23 early complete heart blocks were recorded which were nearly always transient. Only 4 (3.6%) became permanent. 58 had a right bundle branch block (48.4%) and 19 a bifascicular block (15.8%). The early operative mortality (9.7%) appeared to be related to transient complete heart block with 26% deaths in this group. Late mortality was high in patients with permanent heart block (2 out of 4) and also with bifascicular block (3 out of 17). His Bundle recordings showed lengthened H-V intervals in 3 patients, all of whom had transient complete heart block early post-operatively. In conclusion, complete heart block, even when transient, and bifascicular blocks are related to early and late mortality. The indications of permanent pacing, formal for patients with permanent complete heart block, are arguable for patients with bifascicular blocks preceded by postoperative complete heart blocks with long H-V intervals.

Adolescent↗
PubMed1978

[Complete surgical correction of congenital cardiopathies in infants].

The results of total correction of congenital heart defects in the first year of life are presented. Overall surgical mortality in these generally highly symptomatic infants was 35%. The surgical risk is mainly related to the type of defect: mortality is low (10%) in uncomplicated septal defects and in transpositions of the great vessels, higher in the coarctation syndromes (30%), and considerable in complex heart defects. The weight of the infant seems to be another factor, surgical mortality being high when the patient's weight is less than 4.5 kg. Indications for palliative operation or total repair are discussed on the basis of the presented results.

Aortic Coarctation↗