Ingrid Oberhansli

Inhaled Nitric Oxide to Test the Vasodilator Capacity of the Pulmonary Vascular Bed in Children With Long-Standing Pulmonary Hypertension and Congenital Heart Disease

Nitric oxide-induced vasodilator capacity greatly varies among children with pulmonary hypertension and elevated vascular resistance. The decline of this selective response seems to parallel the progression of established vascular disease and thus may be helpful for the selection of patients for operation.

Postoperative Chylothorax in Children: Differences Between Vascular and Traumatic Origin

Twenty-four children with postoperative chylothorax were encountered among 1,264 consecutive thoracic operations over a 7-year period and form the basis of this study. Chylothorax was caused by direct lesion to the thoracic duct or lymphatic vessels in 17 patients and was associated with superior vena cava (SVC) obstruction in seven. Of the latter, five had bilateral chylothorax. Chylothoraces secondary to venous hypertension and thrombosis have a longer interval between operation and diagnosis compared with direct trauma as well as a longer duration and larger volume of chylous drainage. Treatment was entirely nonoperative in 16 patients and operative in 8. Nonoperative treatment consisted of pleural needle aspiration or suction drainage in association with a medium chain triglyceride (MCT) diet (n = 11) or total parenteral nutrition (TPN) after failure of MCT (n = 5). Direct operation on the thoracic duct was performed in 5 patients, four had pleurodesis, and 2 had pleuroperitoneal shunts inserted. All patients were cured of their chylothorax and there were no deaths. Patients with major vein thrombosis were the most difficult to treat. On the basis of this experience, we suggest a step-by-step approach: (1) insertion of chest tube after 3 to 4 pleural punctures; (2) 1-week trial of MCT diet, with intravenous support to correct protein losses; (3) TPN if chylothorax increases or persists with large volumes; (4) Doppler echocardiography or phlebography to rule out obstruction of major thoracic veins; and (5) insertion of TPN line in inferior vena cava in case of such obstruction; and (6) direct surgical approach to the thoracic duct after 4 weeks of unsuccessful nonoperative treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic valve repair by cusp extension with the use of fresh autologous pericardium in children with rheumatic aortic insufficiency

OBJECTIVES Our goal was to evaluate the midterm results of aortic valve repair by a more sophisticated tailoring of cusp extension-taking into account the dimensions of the native aortic cusps-with the use of fresh autologous pericardium. PATIENTS AND METHODS Forty-one children who had severe rheumatic aortic insufficiency (mean age 11.5 +/- 2.7 years) underwent aortic valve repair by means of this cusp extension technique over a 5-year period. Twenty-four of them underwent concomitant mitral valve repair for associated rheumatic mitral valve disease. All children were then followed up by transthoracic echocardiography before discharge, at 3 and 6 months after the operation, and at yearly intervals thereafter. RESULTS Follow-up was complete in all patients and ranged from 3 months to 5 years (median 3 years). No operative and no early postoperative deaths occurred. Only 1 patient died, 9 months after the operation, of septicemia and multiple organ failure. Actuarial survival was 97% at 1 year and has remained unchanged at 3 years. On discharge, the degree of aortic insufficiency was grade 0 for 27 children and grade I for 14. Exacerbation of aortic insufficiency from grade I to grade II was observed in only 1 patient, and none of the children required reoperation for aortic insufficiency during the follow-up period. Mean peak systolic aortic valve gradients at discharge were lower than preoperative values (P =.04), and no significant increase in the peak systolic transvalvular gradient was detected thereafter during the follow-up period. Mean left ventricular dimensions were significantly reduced at discharge when compared with preoperative values (P <.0001). CONCLUSIONS Functional results of aortic valve repair with cusp extension using fresh pericardium have been satisfactory at medium term, particularly in children with a small aortic anulus at the time of initial repair, because the expansion potential of fresh autologous pericardium is equivalent to that of the growing sinotubular junction and aortic anulus diameters.

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.

Frequency of ventricular late potentials and fractionated right ventricular electrograms after operative repair of tetralogy of Fallot

This study was conducted to assess the incidence of abnormalities of ventricular depolarization in sinus rhythm after repair of tetralogy of Fallot and their relation to spontaneous ventricular arrhythmias. Forty-four patients were studied, 10 before surgery (mean age 6.9 years) and 34 after repair (mean age 8.1 years, mean age at surgery 6.5 years, mean interval between surgery and evaluation 11 months). Evaluation was performed by means of body surface and intracavitary signal-averaging techniques, by recording local right ventricular (RV) electrograms at several sites and by 24-hour Holter monitoring (n = 28). No electrophysiologic abnormality was observed in children before surgery. Ventricular late potentials were detected in 18 patients (53%) after repair. Body surface detection of ventricular late potentials was frequently masked by the postoperative right bundle branch block pattern. Local RV electrograms were fractionated in 11 cases (32%) (mean duration 103 +/- 33 ms), most often in the RV outflow tract (n = 9), but no relation was found between fragmentation of RV electrograms and the presence of ventricular late potentials. Spontaneous ventricular arrhythmias occurred in 12 children after repair (43%), but were complex in only 4 patients (14%). There was no correlation between spontaneous ventricular arrhythmias and the presence of ventricular late potentials, presence of fractionated RV electrograms, presence of a proximal right bundle branch block or postoperative hemodynamic status.(ABSTRACT TRUNCATED AT 250 WORDS)

Fungal endocarditis in critically ill children

Abstract All cases of infective endocarditis occurring from January 1990 to December 1996 at our institution were reviewed, with a special focus on fungal endocarditis. Five critically ill children with fungal endocarditis and eleven children with bacterial endocarditis were recorded. The proportion of fungal endocarditis in our series was 5/16 (31%) and Candida albicans (4/5) was the most common fungal pathogen. Only one patient required heart surgery because of a loose patch but all the others were treated only by medical management for cure. The hospital survival rate was 80% (4/5) and the overall long-term survival rate was 60% (3/5) with only one death directly related to fungal infection. Conclusion Despite the small number of cases, a sole medical approach including amphotericin B and long-term fluconazole prophylaxis for the treatment of fungal endocarditis in critically ill children seems to offer an alternative to surgical treatment which may be kept for failure of medical treatment.

Trefoil balloon for aortic valvuloplasty.

A new balloon for valvuloplasty (Trefoil balloon) was successfully used in a 12 year old boy with congenital aortic stenosis. The Trefoil balloon consists of three angioplasty balloons mounted in parallel on a single shaft. When they are inflated simultaneously they produce a rosette that allows blood flow to continue through the valve. The aortic pressure only dropped to 75 mm Hg during a 15 s balloon dilatation at 4 bar (400 kPa). The procedure reduced the transvalvar gradient from 45 to 15 mm Hg.

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)

Hypoplasia of the Posterior Leaflet as a Rare Cause of Congenital Mitral Insufficiency

Abstract A rare case of congenital mitral insufficiency characterized by the hypoplasia of the posterior leaflet is reported. At operation, the mitral valve was successfully repaired by a ring annuloplasty, which created a satisfactory surface of coaptation between the anterior leaflet and the bulky posterior muscular structure. The presence of this posterior muscular structure represents a developmental arrest at the stage of conversion from muscular chordae and leaflets to thin connective structures.

Ventricular late potentials and spontaneous ventricular arrhythmias after surgical repair of tetralogy of Fallot: do they have prognostic value?

OBJECTIVE--To determine the prognostic significance of ventricular late potentials and spontaneous ventricular arrhythmias detected early after surgical repair of tetralogy of Fallot. DESIGN--Prospective observational. SETTING--Cardiology department of a teaching hospital. METHODS--Between June 1984 and June 1991, 104 children (63 boys, 41 girls) were studied by signal averaging and 24 hour ambulatory monitoring after surgical repair of tetralogy of Fallot. Mean (SD) age at operation was 6 (3) years, mean interval between operation and evaluation was 8 (25) months, and the follow up after evaluation was one to 88 (mean 30) months. RESULTS--Ventricular late potentials were detected in 24/104 patients (23%) and spontaneous ventricular arrhythmias in 39/96 patients (38%); usually (in 81%) these were unifocal and rare. Patients with ventricular late potentials were older at operation than patients without late potentials (9 (3) v 6 (3) years, P = 0.002). No correlation was found between the presence of ventricular late potentials and the presence or complexity of spontaneous ventricular arrhythmias early after operation. During the mean follow up of 2.5 years no case of sudden death or sustained ventricular tachycardia was found. CONCLUSION--Short-term prognosis after surgical repair of tetralogy of Fallot is good; ventricular late potentials and spontaneous ventricular arrhythmias are often detected shortly after operation, but in the medium term follow up they do not predict sudden death or serious ventricular arrhythmias.