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)

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)

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.

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.

Hemodynamic effect of isoprenaline and dobutamine immediately after correction of tetralogy of Fallot. Relative importance of inotropic and chronotropic action in supporting cardiac output.

In order to compare the effect of isoprenaline and dobutamine immediately after correction of tetralogy of Fallot, 12 randomly selected patients were studied postoperatively. Left ventricular end-diastolic volume, measured preoperatively by means of left ventricular angiograms in eight patients, was decreased to a mean value of 58.6 +/- 5.5 ml/m2 (mean +/- standard error of the mean). Postoperatively, cardiac output was measured by thermodilution before, during, and after infusion of increasing doses of isoprenaline (0.05, 0.1, and 0.2 micrograms/kg/min) and dobutamine (2.5, 5, and 10 micrograms/kg/min) successively given in each patient. Simultaneously, central venous, left atrial, pulmonary arterial, and systemic arterial pressures were recorded. Cardiac index increased significantly in response to all three doses of isoprenaline. Dobutamine produced only a small increase which was not statistically significant. Stroke volume index did not vary significantly with either drug. Consequently, cardiac index was directly related to heart rate. Preload of the left ventricle as well as afterload was significantly reduced (p less than 0.01 and p less than 0.05, respectively) by isoprenaline but not by dobutamine. An increase in left ventricular work index per minute was found with both drugs; however, only with isoprenaline was the increased work accompanied by a significant increase in cardiac index. We conclude that patients with tetralogy of Fallot usually have a small left ventricle which, immediately after correction, reacts to catecholamines by only an insignificant increase in stroke volume index. Consequently, isoprenaline is more effective than dobutamine in raising cardiac index due to the increase in heart rate. Moreover, it decreases systemic vascular resistances and obviates the need for administration of a vasodilator.

Chronotropic and inotropic supports are both required to increase cardiac output early after corrective operations for tetralogy of Fallot.

To assess the respective roles of chonotropism, inotropism, and afterload reduction in increasing cardiac index early after corrective operations for tetralogy of Fallot, we measured vascular pressures and cardiac output and evaluated left ventricular dimension changes before and after a 35% rise in heart rate over baseline. This rise was induced by atrial pacing with intact atrioventricular conduction, isoproterenol, or atrial pacing together with dobutamine. With atrial pacing, left ventricular end-diastolic diameter decreased (38.7 +/- 4.3 to 34.2 +/- 5.6 mm, p less than 0.05), the shortening fraction (ratio of the difference between left ventricular end-diastolic and end-systolic diameters to left ventricular end-diastolic diameter) remained constant, and stroke volume index was reduced (28.8 +/- 4.5 to 19.7 +/- 4.6 ml/m2, p less than 0.05). As a result, cardiac index was left unchanged. When dobutamine was added as supplemental inotropic support, left ventricular end-diastolic diameter remained constant, shortening fraction increased (30% +/- 5.4% to 36% +/- 3.3%, p less than 0.05), and cardiac index rose significantly (3.04 +/- 0.61 to 4.18 +/- 0.85 L/min/m2, p less than 0.05). Heart rate acceleration with isoproterenol, combining chronotropism, positive inotropic support, and afterload reduction, slightly increased left ventricular end-diastolic diameter, significantly raised shortening fraction, and markedly enhanced cardiac index (3.03 +/- 0.55 to 4.9 +/- 1.09 L/min/m2). Atrial pacing with intact atrioventricular conduction, as an isolated chronotropic stimulus, is not suited to increase cardiac index early after operations for tetralogy of Fallot unless additional inotropic support is simultaneously provided.

Intrathoracic neuroblastoma presenting with neonatal cardiorespiratory distress.

We report an unusual presentation of congenital intrathoracic neuroblastoma. Severe respiratory distress was present at birth and several salient clinical signs were suggestive of neonatal myocarditis. Excessive catecholamine secretions may have caused the observed cardiac dysfunction. Peculiar previously unreported cutaneous lesions were also noted in this case.

Prosthetic heart valve replacement in children. Results and follow-up of 273 patients.

We report the results and long-term follow up in 273 children (aged 2 to 16 years) who underwent prosthetic valve replacement. Mechanical valves (mostly Starr-Edwards) were used in almost all, and in 62 children more than one valve was replaced. Operative mortality was 4.7%. Actuarial survival curves (including hospital mortality) indicate a 86% survival rate at 5 years and 75% at 10 years. For isolated mitral valve prostheses (the largest subgroup), the figures are 87% at 5 years and 82% at 10 and 15 years. The main complication was thromboembolism, which occurred at a linearized rate of 2.7 per 100 patient-years. Actuarial curves indicate that 88% of patients are embolus free at 5 years, and 77% at 10 years. No patient with aortic valve replacement only had an embolism. Five of eight tricuspid prostheses thrombosed. Patients given aspirin and dipyridamole only did not have a higher rate of thromboembolic events than those given warfarin. There were five cases of endocarditis (two fatal) and four of dehiscence. No patient so far has needed replacement of a prosthesis because of somatic growth. Thus valve replacement can be performed with low mortality in children, and with satisfactory long-term survival. Thromboembolism remains a significant problem, although it appears to be less common than in adults. In this study, treatment with antiplatelet drugs only did not carry a higher rate of thromboembolic events than did treatment with warfarin.

Regression of cardiac insufficiency after ambulatory intravenous deferoxamine in thalassemia major.

A case of severe cardiac failure due to iron overload in a patient with beta-thalassemia major is reported. The patient was successfully treated with high-dose ambulatory intravenous deferoxamine (desferrioxamine). This type of chelation appears to be a valuable alternative to subcutaneous deferoxamine administration in the presence of severe iron overload.

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.

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.

Multiple-leaflet mitral valve as a rare cause of congenital mitral insufficiency.

A rare case of congenital mitral insufficiency characterized by six well-demarcated leaflets of mitral valve and annular dilatation is reported. At operation, the mitral valve was successfully repaired by resection of the posterior median leaflet with subsequent annular plication, closure of unusual valvular tissue divisions, and ring annuloplasty.

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)

[Pulsed Doppler and bidimensional echocardiography in patent ductus arteriosus]. / Doppler pulsé et échocardiographie bidimensionnelle dans le canal artériel.

The classical form of patent ductus arteriosus (PDA) does not usually pose any difficulty in diagnosing. When the auscultatory signs are atypical, for example in the newborn or in cases with pulmonary hypertension, pulsed Doppler echocardiography may be a useful diagnostic aid. This study reports the results of pulsed Doppler examination in PDA. Twenty-four children with a suspected PDA underwent pulsed Doppler examination during 2D echocardiography. This population was divided into 2 groups; Group I: children who underwent catheterisation, and group II: in which catheterisation was not performed. The mean age in Group I was 7 years compared to 50 days in Group II, which mainly comprised newborn and premature babies. Direct visualisation of PDA by 2D echo was attempted in all cases. The search for a PDA by pulsed Doppler was made by positioning the sample volume at the bifurcation of the main pulmonary artery. PDA is associated with turbulent systolo-diastolic flow away from the transducer. Suprasternal and subcostal views were also used. In Group I (13 cases) PDA was directly visualised by 2D echo in 7 children (53 p. 100). By comparison, pulsed Doppler examination diagnosed all 13 cases of PDA; these results were confirmed at catheterisation or surgery. In Group II (11 cases) direct visualisation of PDA was successful in 6 cases (54 p. 100). Pulsed Doppler was non-specific, showing typical flow disturbances in 8 cases and systolic turbulence in 3 cases at the level of bifurcation.(ABSTRACT TRUNCATED AT 250 WORDS)

[Interauricular communication and mitral prolapse. An echocardiographic and angiographic study]. / Communication interauriculaire et prolapsus mitral. Etude échocardiographique et angiographique.

The association of atrial septal defect (ASD) and mitral valve prolapse (MVP) is well known but its precise incidence has not yet been established. Most previous publications have only been angiographic studies and the diagnostic criteria of MVP were, therefore, controversial. In this study, 61 consecutive patients, adults and children, underwent M mode echocardiography and cardiac catheterisation with cineangiography. In the adult group echocardiographic MVP was observed in one of 23 patients with secundum ASD. These findings were confirmed on angiography in addition, four other cases were observed in patients without systolic clicks or pansystolic or late systolic murmurs. MVP was observed in four out of 27 children with secundum ASD on M mode echocardiography and all cases were confirmed at angiography. In contrast to the adult group, no additional cases were demonstrated. Three out of 11 patients with ostium primum defects had MVP at echo and/or angiography, a finding which was probably related to the common atrioventricular canal. Follow-up echocardiography 6 weeks after surgical repair of ASD showed persistent but less marked MVP in all cases. Echocardiographic evidence of MVP was therefore demonstrated in 5 out of 50 patients (10%) with secundum ASD. It was more common in children (15%) than in adults (4%). These results differ from those previously published, probably because of differences in method (use of echo and angiography), diagnostic criteria, size of atrial shunt and the incidence of associated mitral regurgitation. The prevalence of MVP in patients with ASD may have been overestimated in previous publications.