PubMed Health⌕ Search

Biomedical subjects

B Friedli

Publications and source records attributed to B Friedli.

At least 55 records · Page 3Linked to original sources
PubMed1993

Relief of severe pulmonary hypertension after closure of a large ventricular septal defect using low dose inhaled nitric oxide.

A 16-month-old girl developed severe pulmonary hypertension after closure of a large ventricular septal defect. All conventional therapeutic measures failed; an attempt to add nitric oxide at a continuous low dose to the inspired gas allowed resolution of pulmonary hypertension and low cardiac output. This report documents that continuous inhalation of low dose nitric oxide is capable of selective resolution of pulmonary hypertension following cardiac surgery for a large septal defect in a child. This suggests that a transient dysfunction in the release of nitric oxide by the pulmonary endothelial cell is responsible for the vasoconstriction.

Administration, Inhalation↗
PubMed1993

Physiological pulmonary branch stenosis in newborns: 2D-echocardiographic and Doppler characteristics and follow up.

Transient systolic murmurs in neonates and premature infants due to mild left (LPA) and right (RPA) pulmonary branch stenosis is recognized but follow up studies are lacking. We studied echocardiographically 21 neonates with murmur and 10 controls. Diameters of the main pulmonary artery (MPA), LPA and RPA were smaller in patients with murmur. Colour-coded Doppler showed turbulent flow in LPA and RPA in 20/21 (95%) patients and flow velocities of both pulmonary branches were significantly higher than in controls. The follow up study at 3 months in 14/21 (67%) patients showed absent or decreased murmur in 9 (64%). Echographically, absolute and relative diameters of LPA and RPA increased whereas the ratio of MPA/aorta did not change suggesting accelerated growth or dilatation of the pulmonary branches. Flow velocities decreased significantly in the branches. Thus, transient systolic murmurs in neonates are associated with temporary relative hypoplasia of the pulmonary branches which showed increased growth leading to disappearance of the murmur in most cases within 3 months of life.

Arterial Occlusive Diseases↗
PubMed1993

Cine gradient-echo MR imaging in the evaluation of cardiovascular diseases.

The contributions of cine gradient-echo (GRE) magnetic resonance imaging were compared with those of spin-echo (SE) imaging for the evaluation of morphologic, functional, and flow alterations in 78 cases of congenital and acquired cardiac diseases. High temporal and spatial resolution cine GRE images (256 phase-encoding steps, 256 x 256 acquisition matrix interpolated to 512 x 512 for display, 16-64 frames per cycle) and SE images were acquired in each case. Cine GRE images provided a better diagnostic evaluation than SE images in several cases: (a) both masses and thrombi could be differentiated from flow artifacts; (b) abnormalities in cardiac function, such as infarction, abnormal wall motion, and ventricular dysfunction, could be evaluated; (c) small defects, shunts, and abnormal communications could be clearly seen; and (d) valvular regurgitations, poststenotic flow alterations, and aortic coarctation could be assessed. Cine GRE imaging was also valuable for postoperative evaluations. The authors believe that cine GRE imaging is a useful addition to SE sequences, especially for the assessment of blood flow and cardiac function.

Adolescent↗
PubMed1992

[Transesophageal echocardiography--is it indicated for children undergoing heart surgery?].

In adults transesophageal echocardiography (TEE) has become a well-established method for the assessment of cardiac malformations. In children the transthoracic approach (TTE) gives excellent resolution and cardiac malformations can be well defined in most of the cases. Uncertainty may, nevertheless, exist in complex anomalies in spite of TTE and angiography or after surgical interventions. Recently pediatric 5-mHz TEE probes have been developed with acceptable diameters of 6, 9 and 11 mm. The feasibility and the potential risks of TEE were studied in 47 patients, aged from 5 months to 16 years (mean 5 9/12 years), weighing from 5 to 47 kg (mean 19.7 kg). 35 children had congenital malformations: 15 VSD + PS, 5 VSD + PHT, 3 ASD, 5 A-V canal malformations, 1 tricuspid atresia, 2 subvalvar aortic stenosis, 3 endocarditis, 1 normal. Twelve children had rheumatic heart disease. Eight patients had more than 1 TEE. The examination was performed either under general anaesthesia just before of after surgical intervention in 32 or under sedation and with local anaesthesia in the others. There was no complication, but in 3 intubated children under 3 years of age TEE was not possible; obstruction of the endotracheal tube occurred. Adequate imaging was obtained in most of the children with one or the other probe. Additional information was obtained in 28 patients (52%). In 5 of them these informations modified the surgical procedure. We conclude that TEE is feasible in children and has a low risk of complications when practised with care.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Ventricular late potentials and induced ventricular arrhythmias after surgical repair of tetralogy of Fallot.

Ventricular tachycardia (VT) and sudden death are rare but recognized complications after surgical repair of tetralogy of Fallot. We prospectively studied 31 patients (19 boys and 12 girls, mean age +/- standard deviation 7 +/- 4 years) with postoperative tetralogy of Fallot, by means of right-sided cardiac catheterization, 24-hour Holter monitoring, body-surface and intracavitary signal-averaging (gain 10(5) to 10(6), filters of 100 and 300 Hz) and programmed ventricular stimulation (1 and 2 extrastimuli, 3 basic cycle lengths, right ventricular apex and outflow tract). All patients were asymptomatic and none had documented or suspected ventricular arrhythmias. Ventricular late potentials were detected in 10 of 31 patients (32%) and spontaneous ventricular arrhythmias in 12 of 31 patients (39%). No sustained VT was induced by programmed ventricular stimulation but nonsustained VT was induced in 3 patients (10%). Patients with inducible VT more often had late potentials (3 of 3 vs 7 of 28, p less than 0.01), and spontaneous ventricular premature complexes (VPCs) during Holter monitoring (3 of 3 vs 9 of 28, p less than 0.05). To predict VT inducibility, late potentials had a sensitivity of 100%, a specificity of 75%, a positive predictive value of 30% and a negative predictive value of 100%. For spontaneous VPCs, the figures were 100, 68, 25 and 100%, respectively. It is concluded that shortly after repair of tetralogy of Fallot, the presence of both spontaneous VPCs and ventricular late potentials are associated with an increased incidence of inducible VT. Conversely, the absence of VPCs and ventricular late potentials may identify patients at low risk of subsequent ventricular arrhythmias.

Adolescent↗
PubMed1991

Stenting of superior vena cava and inferior vena cava for symptomatic narrowing after repeated atrial surgery for D-transposition of the great vessels.

Double venous stenting of the superior vena cava and inferior vena cava was successfully performed after failed balloon angioplasty in a young woman who had venoatrial narrowing and kinking after repeated Mustard procedure for D-transposition of great vessels. Self-expanding metallic stents were used. Angiography showed that the first stent was fully patient after six months when a second stent was implanted. This operation was followed by sustained clinical improvement. The present report shows the feasibility and success of stenting of the great veins when postoperative narrowing or kinking is unresponsive to balloon angioplasty alone.

Adolescent↗
PubMed1991

Atrial natriuretic factor after heart operations in children. Relation to hemodynamic and renal parameters.

The purpose of this study was to measure changes in serum atrial natriuretic factor concentrations immediately after heart operations in children under baseline conditions and in response to continuous infusion of dopamine (2.5 and 5.0 micrograms/kg/min). During control periods, levels of atrial natriuretic factor were elevated at 190 +/- 24 and 199 +/- 36 pg/ml. The cardiac index was 2.6 L/min/m2 and the renal plasma flow was decreased to 269 +/- 41 ml/min/1.73 m2, indicating a state of renal vasoconstriction (mean renal fraction of cardiac index of 10.0% +/- 1.0%). The mean sodium fractional reabsorption was 99.0% +/- 0.2%. During dopamine infusion, atrial natriuretic factor concentrations increased to 259 +/- 57 pg/ml and to 280 +/- 56 pg/ml, with dopamine 2.5 and 5.0 micrograms/kg/min, respectively (p = not significant), whereas left atrial pressure decreased from 11.7 +/- 0.9 mm Hg during the control period to 10.1 +/- 0.9 and to 9.9 +/- 1.0 mm Hg (p less than 0.05). No correlation was found between changes in left atrial pressure and atrial natriuretic factor levels. Dopamine at 5 micrograms/kg/min increased the cardiac index to 3.0 +/- 0.2 L/min/m2 (p less than 0.001) and the renal plasma flow to 406 +/- 61 ml/min 1.73 m2 (p less than 0.001), alleviating the renal vasoconstriction. The mean urinary sodium excretion increased to 0.33 +/- 0.08 mmol/kg/hr (p less than 0.01). The atrial natriuretic factor plasma concentrations were not related to the urinary sodium excretion, renal plasma flow, or glomerular filtration rate during the control period or during dopamine treatment. These data indicate that after heart operations in children, low urinary sodium excretion occurs despite high circulating atrial natriuretic factor levels. Atrial natriuretic factor concentrations were related neither to left atrial pressures nor to the renal changes induced by dopamine.

Adolescent↗
PubMed1991

Late results of surgery for congenital heart defects.

Surgery for congenital heart defects started 50 years ago with "closed" procedures, and open heart surgery is in its forth decade. Thus, long-term results are now available. Although a majority of patients lead normal lives, problems do exist. Hemodynamic anomalies can be related to residual lesions or to persistent systemic hypertension (after coarctation repair) or pulmonary hypertension (after late repair of left to right shunt lesions). Right or left ventricular dysfunction may be observed, due to longstanding overload, hypoxia or to the open heart procedure itself. Rhythm disturbances have a tendency to increase with the passage of time after surgery. After ventricular surgery (repair of ventricular septal defect and tetralogy of Fallot), conduction defects and ventricular arrhythmias are prevalent. They may lead to late sudden death. After atrial surgery, sinus node dysfunction and atrial arrhythmias are observed. Problems related to growth of the patient exist essentially in cases where foreign material (conduits, prostheses) have been implanted. Many patients, with definitive repair or palliative operation, have become adults. This is a new challenge for the adult cardiologist, and it is a duty of the pediatric cardiologist to hand over his knowledge of this pathology.

Adolescent↗
PubMed1990

[Intermediate results of balloon valvuloplasty in children with congenital aortic valve stenosis].

Eleven children with aortic valve stenosis requiring treatment underwent percutaneous balloon valvuloplasty instead of surgery. Three were newborns or infants and 8 were aged 2-18 years. Aortic valve gradient was 45-160 mm Hg (mean 83 mm Hg) before valvuloplasty; after the procedure the gradients ranged from 7-43 mm Hg (mean 25). One newborn with critical stenosis and associated left ventricular fibroelastosis died 48 hours after valvuloplasty. All others showed marked clinical improvement after the procedure. Main complications included permanent loss of peripheral pulses in the catheterized leg (2 cases, age 2 months and 20 months) and aortic valve regurgitation. This was estimated as moderate (++) in 2 and moderately severe (3+) in one; it was minimal or absent in the others. All patients were followed up for 3 months to 4 years. There was one recurrence of aortic stenosis, 2 years after valvuloplasty, requiring surgery. Two infants also underwent late surgery after successful valvuloplasty, one for mitral valve replacement and one for severe subvalvular aortic stenosis. In the remaining seven children the good initial result was maintained. Aortic valve gradient was estimated with Doppler at regular intervals and did not increase significantly over the follow-up period. In conclusion, balloon valvuloplasty is an alternative to open heart surgery in aortic valve stenosis in the young; both procedures are palliative.

Adolescent↗
PubMed1990

[Interventional catheterization in the treatment of congenital and acquired heart defects].

The treatment of heart defects by interventional catheterization started in 1982, when the first report on balloon dilatation of pulmonary valve stenosis was published. Similar techniques have since been extended to many other lesions. Presently, two types of catheter intervention have come into use. The first is dilatation of stenotic lesions by inflatable balloons: the main defects treated include pulmonary valve stenoses, aortic valve stenoses, coarctation of the aorta and peripheral pulmonary artery stenoses. Second, it is now possible to close defects and unwanted vessels, such as a persistent ductus arteriosus, with umbrella-like devices introduced through catheters. While balloon dilatation has clearly become the treatment of choice for pulmonary valve stenosis, other applications remain either controversial (e.g. balloon dilatation of coarctation) or experimental (e.g. closure of atrial or ventricular septal defects). Time will tell what is the exact role of interventional cardiology, keeping in mind that surgery provides excellent results with minimal morbidity and mortality in these lesions.

Cardiac Catheterization↗
PubMed1990

Hemodynamic effects of amrinone in children after cardiac surgery.

The hemodynamic effects of amrinone were assessed in seven children following cardiac surgery. Amrinone was administered as a bolus of 1 mg kg-1 body wt., followed by continuous infusion at 10 micrograms kg-1 min-1 for 1 h and two stepwise increases to 20 and 40 micrograms kg-1 min-1 for 30 min each. Hemodynamic data were obtained and plasma concentrations of amrinone measured 1 h after the bolus dose and immediately before each increment of the infusion rate. Amrinone levels ranged from 0.7 to 2.3 mg l-1. Administration of amrinone lowered systemic vascular resistance from 20.0 +/- 4.3 to 16.5 +/- 4.6 mmHg l-1 min-1 m-2 (p less than 0.05) and reduced mean arterial pressure from 71.7 +/- 9.5 to 62.6 +/- 13.5 mmHg (p less than 0.05) at the highest infusion rate, confirming the known vasodilative effect of the drug. However, these effects did not result in a statistically significant increase in stroke volume (35.0 +/- 7.5 to 35.5 +/- 7.0 ml m-2, NS) or cardiac index (3.10 +/- 0.50 to 3.20 +/- 0.40 l min-1 m-2). One additional patient, in whom a higher loading dose was tried in order to achieve a higher plasma concentration, developed systemic hypotension. A correlation was established between the plasma concentrations of amrinone and the percentage decrease in systemic resistance (r = 0.70, p less than 0.05). These results suggest that in children after open heart surgery, amrinone acts primarily as a systemic vasodilator, with questionable inotropic effect. Accordingly, its use should be restricted to children with severe cardiac failure and documented highly elevated afterload.

Adolescent↗
PubMed1990

Electrophysiological studies after the Mustard and Senning operations for complete transposition. Do they have prognostic value?

Overall, long-term survival after the Mustard or Senning operation is good, but late arrhythmias remain a concern. Whether postoperative electrophysiological investigations can identify patients at risk of developing serious arrhythmias is unknown. In this study, 16 children who underwent electrophysiological study after the Mustard or Senning operation for complete transposition (the combination of a concordant atrioventricular and a discordant ventriculo-arterial connexion) were followed up for one month to 9 years (mean 4.33 years) after this investigation. At the electrophysiological study, sinus nodal dysfunction was diagnosed in 9/16 patients, and abnormalities of atrial conduction and refractoriness in 7/13. During follow-up, 7 children developed clinical evidence of the sick sinus syndrome. When considering corrected sinus node recovery time as the only electrophysiological parameter, the sensitivity of predicting sick sinus syndrome from the electrophysiological study was 42%, and specificity 66%. The sensitivity increased to 71% if additional electrophysiological criteria of sinus node dysfunction were included, such as sinuatrial conduction time or sinus node entrance block, but specificity dropped to 55%. Atrioventricular conduction disturbances were rare. Thus, abnormalities at electrophysiological studies after the Mustard or Senning operations are frequent, but identification of patients at risk of developing sick sinus syndrome remains difficult.

Arrhythmia, Sinus↗
PubMed1990

Atrial natriuretic factor in patients with congenital heart disease: correlation with hemodynamic variables.

To investigate the alpha-atrial natriuretic factor in congenital cardiac malformations, three groups of children, aged 7 months to 16 years, with different hemodynamic situations were studied during routine cardiac catheterization. Twenty-one (group I) had tetralogy of Fallot, 24 (group II) had a left to right shunt with pulmonary hypertension and 12 (control group) had a minor cardiac lesion. Alpha-atrial natriuretic factor levels were determined by a radioimmunoassay on blood samples from the inferior vena cava, right atrium, pulmonary artery, left atrium and aorta. To evaluate the effect of an acute volume load, measurements of hormone and pressures were repeated after right ventriculography. Alpha-atrial natriuretic factor levels varied over a wide range in all groups and in all chambers investigated. Nevertheless, children with pulmonary hypertension had significantly higher levels of the hormone (p less than 0.01) and were well separated from the control group, but less well from those with tetralogy of Fallot. A 50% increase of alpha-atrial natriuretic factor from the inferior vena cava to the right atrium occurred in patients with shunt lesions with pulmonary hypertension and in patients with tetralogy of Fallot (p less than 0.001) and a further 30% increase from the right atrium to the pulmonary artery (p less than 0.05). After right ventriculography, a 100% to 200% increase of alpha-atrial natriuretic factor was observed in the total sample (p less than 0.001). A positive correlation was observed between right atrial mean pressure and right atrial alpha-atrial natriuretic factor (r = 0.63) and between pulmonary artery mean pressure and pulmonary artery alpha-atrial natriuretic factor (r = 0.61).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Congenital intrathoracic left ventricular diverticulum in an adult.

A 53-year-old woman without any risk factors for coronary artery disease was found to have a congenital intrathoracic left ventricular diverticulum with a narrow long connection to the left ventricular cavity. Coronary angiography revealed normal coronary arteries. The diverticulum was resected and showed three normal cardiac layers. This is an extremely rare finding in the adult population.

Diagnosis, Differential↗
PubMed1989

Endomyocardial fibrosis in the child.

Endomyocardial fibrosis is a rare disease in children and has been mainly observed in tropical Africa, seldom in Europe. Its precise aetiology remains unknown. New surgical procedures have recently led to better survival. Four children, a 5 year old Swiss boy and 3 African girls, aged 12 to 14 years, were submitted with global heart failure class III to IV of the NYHA classification. Two patients had eosinophilia on admission. A third had a history of transient eosinophilia. The echocardiographic examination showed a very typical picture. In 3 patients (2 f and 1 m) both ventricles were involved; in one girl only the left ventricle. Decreased ventricular distensibility with impaired filling of the left and/or right ventricle was present in all. Diastolic pressures ranged between 24 and 35 mmHg; the systolic function was satisfactory in 3 children (ejection fraction [EF] of 44 to 61%) and severely decreased in the fourth (EF 10%). Three patients underwent endocardectomy: both ventricles in 1 case, only the left in 2 cases. Mitral valve repair by means of the Carpentier ring was done once, valve replacement once (Starr-Edwards prothesis). One child died; the 2 surviving patients showed a distinct improvement in their clinical state and are now in class II of the NYHA classification. Echocardiographic and catheter investigations show, however, persistence of the restrictive cardiomyopathy. Thus, surgical intervention must be considered a palliative procedure in these cases. The diagnosis can clearly be made nowadays with bidimensional and Doppler echocardiography.

Adolescent↗
PubMed1989

Radionuclide evaluation of right ventricular wall motion after surgery in tetralogy of Fallot.

Regional wall motion patterns in tetralogy of Fallot and its postoperative modifications by electrical and hemodynamic factors were assessed by Fourier analysis of gated radionuclide angiograms in 24 studies performed in children after surgical correction of tetralogy of Fallot. The range of right ventricular (RV) phase angles (standard deviation of the peak [SDP] of RV) as well as the difference between RV and LV (delta MPh) were used as indices of the synchronicity of wall motion and were correlated with RV apical electrical activation time determined by endocardial electrical mapping. Postoperative studies were divided into two groups according to apical activation: (a) those involving right bundle branch block (RBBB) (nine patients), and (b) those involving distal RBBB (15 patients). delta MPh was longer in proximal than in distal RBBB. Best discrimination between the two groups was obtained with SDP of RV (proximal = 24 degrees +/- 3 degrees, and distal = 17 degrees +/- 2 degrees; p less than 0.0001). These results showed that the range of ventricular phases measured by the SD of the phase distribution of the right ventricle is a good index for distinguishing between proximal and distal RBBB after cardiac surgery.

Adolescent↗