Biomedical subjects

D Sidi

Publications and source records attributed to D Sidi.

At least 181 records · Page 10Linked to original sources

PubMed1988

Anomalous left coronary artery arising from the pulmonary artery in infancy: is early operation better?

From January 1975 to January 1987, 21 consecutive infants aged less than six months (mean (SD) 2.6 (1.2] were admitted with anomalous origin of the left coronary artery from the pulmonary artery. In the first 12 patients, who were seen up to 1982, operation was performed after the age of one year (mean (SD) 29 (29) months) (group 1). The next nine infants, seen from 1983 to 1987, had their operations within a few weeks of the onset of symptoms (mean (SD) age 4.8 (1.4) months) (group 2). In group 2 the left coronary artery was relocated into the aorta, whereas in group 1 there was additional resection of the left ventricular wall or mitral valvoplasty or both. At presentation there were no differences in age, clinical condition, heart enlargement, and echocardiographic left ventricular dysfunction between groups 1 and 2. Seven of the 12 patients in group 1 died, five while they were awaiting operation (three died suddenly at home) and two at operation. The five survivors are doing well 6.4 (3.1) years after operation with normal left ventricular function which improved slowly over several months after operation. Two of the nine patients in group 2 died; both deaths occurred at or soon after operation. The seven survivors are doing well 1.8 (0.9) years after operation. In three, left ventricular function recovered within three weeks; and there was even partial or total regression of the Q waves in the supposedly necrotic areas. In the remaining four the pattern of improvement in left ventricular function resembled that in group 1. Operation should be undertaken early in infants with anomalous left coronary artery arising from the pulmonary artery because the procedure is relatively safe, prevents a high natural mortality, and offers a better chance of a faster recovery of left ventricular function.

Age Factors↗

PubMed1988

Fate of pulmonary artery after anatomic correction of simple transposition of great arteries in newborn infants.

From April 1984 to April 1987, surgical anatomic correction was performed in 86 newborn infants, 2-23 days old (6.8 +/- 3.6 days, mean +/- SD) with simple transposition of the great arteries. In all patients, the pulmonary artery was reconstructed by end-to-end anastomosis according to the Lecompte maneuver, including eight patients with side-by-side position of the great arteries. Three different approaches were used. In the first 10 patients (group 1, six survivors), two separate patches of preserved tanned pericardium were used to reconstruct the pulmonary artery, whereas in the next 15 patients (group 2, 13 survivors), a single patch of the same material was used, and in the last 61 patients (group 3, 56 survivors), surgery was performed with a single patch of fresh autologous pericardium. Among the 75 survivors, 68 (including six in group 1, 12 in group 2, and 50 in group 3) were followed serially for at least 6 months (6-48 months, 26 +/- 9 months) with sequential noninvasive evaluations. At follow-up, all were asymptomatic with normal growth. Two patients with severe pulmonary artery stenosis (group 1) were successfully reoperated on. Four infants with moderate pulmonary artery stenosis have been followed medically and have had stable right ventricular pressures. The last 62 patients have normal or near-normal right ventricular pressures. The spatial relation of the great arteries did not affect the quality of the results. Group 1 had clearly the worst results.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗

PubMed1988

Effect of beta-adrenergic receptor blockade on responses to acute hypoxemia in lambs.

We studied the effects of beta-adrenergic receptor blockade on general circulatory and metabolic responses to moderate (FIO2 = 0.09) acute hypoxemia in newborn (protocol 1) and 3-wk-old (protocol 2) lambs, and on regional blood flow distribution in newborn lambs (protocol 1). Via a left thoracotomy we placed an electromagnetic flow transducer around the ascending aorta and inserted various vascular catheters. After 2 days of recovery, the lambs were studied. In protocol 1, we measured cardiovascular variables and regional blood flow distribution during control conditions, after 45 min of acute hypoxemia, and after 0.5 mg/kg of propranolol during acute hypoxemia. In protocol 2, we measured cardiovascular variables during control conditions and after 45 min of acute hypoxemia with and without propranolol pretreatment. In both groups, propranolol limited the increase in cardiac output and heart rate caused by hypoxemia, and thus decreased oxygen delivery. However, propranolol also decreased oxygen consumption so that pulmonary arterial pO2 was either higher (protocol 1) or the same (protocol 2) as during acute hypoxemia alone. Neither metabolic acidosis nor hypothermia ensued. In protocol 1, propranolol decreased renal, carcass, and most importantly, myocardial blood flows. However, myocardial O2 consumption also fell, coronary sinus pO2 increased, and blood was redistributed toward the subendocardium, suggesting that myocardial perfusion improved. Thus, beta-adrenergic receptor blockade during acute moderate hypoxemia may have a beneficial effect by reducing total body and myocardial oxygen demand in excess of the reduction in oxygen delivery.

Acute Disease↗

PubMed1988

[Cardiac transplantation in the infant and young child. Preliminary results].

Between January and December, 1987, a programme of heart transplantation in paediatrics was designed and carried out in 9 children by the medical and surgical teams of the Necker/Enfants Malades-Laënnec hospitals group, Paris. Six of the patients were infants of less than 2 years (4 were under one year), and the oldest child was 10 years old. All patients seemed to be condemned to an early death either because their congenital heart disease was beyond the resources of conventional surgery (6 cases) or because their dilated cardiomyopathy was refractory to all medical treatments. Three children died at the end of the operation or a few days afterwards, due to poor quality graft (1 case), fulminating bacterial superinfection (1 case) or intractable pulmonary hypertension (1 case). The remaining 6 children are now living as normally as possible in their respective families. The long-term immunosuppressive treatment consists of cyclosporine and azathrioprine; corticosteroids are only used at the very beginning of treatment or in case of graft rejection. Only two episodes of rejection, confirmed by endomyocardial biopsy, were observed in the same patient during the first postoperative month. Biopsy was never performed systematically in order to spare the patient's vein, and the diagnosis of rejection was suspected on clinical grounds.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopsy↗

PubMed1988

[Development of aortic valve stenosis in infants and children. Apropos of 66 cases hospitalized from 1973 to 1984].

Sixty-six children aged over 6 months hospitalized for isolated aortic valve stenosis without cardiac failure but with a transvalvar systolic pressure gradient of more than 40 mmHg were followed up and re-evaluated for a mean period of 5.4 +/- 3.5 years. Twenty-two children who were asymptomatic, had no ST-T changes and had a less than 60 mmHg gradient were not operated upon; they remained stable over a mean period of 5.4 +/- 3.4 years; their gradient was not significantly modified (53 instead of 51 mmHg) and none of them underwent surgery. Forty-four children with symptoms and/or a more than 60 mmHg gradient underwent valvotomy under extracorporeal circulation without mortality. Surgery was effective against the major symptoms in all cases, and it reduced the gradient from 75 +/- 25 to 36 +/- 18 mmHg at the expense of aortic regurgitation in 7 cases, 2 of them with significant haemodynamic repercussions. During the follow-up period (5.8 +/- 3.7 years) 1 patient died of bacterial endocarditis, 5 were reoperated upon (with prosthesis in 4) without mortality and with 4 good results, and 1 patient underwent valvoplasty which proved partially effective but resulted in moderate aortic regurgitation. All other children are now doing well; 29 are completely asymptomatic and without ST-T changes at rest or during exercise. We conclude that aortic valve stenoses with moderate gradient are very stable at mid-term and that surgical valvotomy is a generally effective and low-risk procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1988

[Heart and heart-lung transplantation in the child. Indications, methods and results].

Over a 20 month period, 19 children aged 13 days to 15 years (10 under 3 years), received a heart transplantation (isolated: 16 cases, heart-lungs: 3 cases). There were 5 early deaths and 2 during the 3rd postoperative month (total: 44%). Postoperative period is currently over for 8 of the 9 survivors, who lead a normal life, with rather simple constraints: oral cyclosporin-azathioprine immunosuppressive therapy, monthly evaluation in the out-patient department. The method is relatively simple when it concerns heart transplantation. It is quite heavier and complex when it concerns heart-lung transplantation. On the whole, subject to a rigorous selection of the transplant (whose later dysfunction was the major cause of failure, with bacterial or viral infections), these methods find reasonable indications in a number of heart and/or lung malformations or dysfunctions inaccessible to conventional treatments or which used up their resources, making short-term death likely.

Adolescent↗

PubMed1988

[Practical aspects in the surveillance of heart and heart-lung grafts in children].

The short and middle term survivors of the 19 transplanted children (heart and heart-lungs) of our program are treated with an association of cyclosporine and azathioprine. The detection of rejection is the main worry and relies on endomyocardial biopsy, but this investigation may be dangerous and lowers the available veins of smaller children. Thus, we use it only for the situations of clinical suspicion (18 times in 20 months in 8 children, which proved rejection 6 times in 3 patients). Renal function supervision is careful and comprises systematic renal biopsy; tubulo-interstitial lesions were constant: minimal 3 times, moderate 3 times. This prompts to prescribe the lowest possible cyclosporine dosages which ensure an effective residual blood level (100-300 ng/ml). In case of heart-lung transplantation (3 cases), pulmonary rejection is difficult to prove, opportunistic infections more frequent and severe, and the tracheal suture is responsible for complications (stenosis in 2 cases). By and large, the constraints of supervision are reasonable and allow an almost normal life.

Child↗

PubMed1988

Switch operation for transposition of the great arteries in neonates. A study of 120 patients.

From March 1984 to January 1987, anatomic surgical correction was performed on 110 newborn infants (2 to 23 days old, mean 7.8 +/- 3.5, standard deviation) with simple transposition of the great arteries and 10 additional neonates (7 to 30 days old, mean 17.9 +/- 8.3, standard deviation) with transposition and a large ventricular septal defect. All had preoperative catheterization. Ninety-six percent of the patients underwent balloon atrial septostomy and 90% received prostaglandin E1 infusion until the time of the operation. The anatomy of the coronary arteries according to the Yacoub classification was as follows: type A, 82 patients; type B, 5 patients; type C, 4 patients; type D, 23 patients; and type E, 6 patients. Continuous hypothermic bypass with no circulatory arrest was used for all patients except two. Myocardial protection was ensured by crystalloid cardioplegia. Coronary artery relocation was performed according to the Yacoub technique with some modifications, and pulmonary artery reconstruction was done according to the Lecompte maneuver in all patients, even when the great vessels had a side-by-side relationship. The proximal pulmonary artery was reconstructed with two circular patches for the first 10 patients and with a single large posterior patch for the last 110 patients. Tanned heterologous pericardium was used for the first 25 patients and autologous native pericardium for the last 95 patients. The perioperative mortality rates were 8.3% for the entire series and 5.4% for the last 110 patients, with no deaths in the group having transposition plus ventricular septal defect. Late death from acute myocardial infarction occurred in two patients in the second month after operation. No patient was lost to follow-up, which ranged from 2 to 46 months (mean 16 +/- 11.2, standard deviation). The follow-up included sequential noninvasive evaluations and 32 catheterizations performed 10 to 18 months postoperatively. Two patients were reoperated on for pulmonary stenosis caused by retraction of the two heterologous pericardial patches, but neither died. Six others have mild to moderate pulmonary stenosis. Two patients have trivial aortic regurgitation. None have aortic dilatation or supravalvular aortic stenosis. The 108 survivors have no cardiovascular symptoms. They all are in sinus rhythm, have normal left ventricular function, have no ischemic problems, and receive no medication.

Coronary Vessels↗

PubMed1987

Pulmonary artery "stop-flow" angiography to visualize the anomalous origin of the left coronary artery from the pulmonary artery in infants.

In five infants, anomalous left coronary from the pulmonary artery (ALCA) was diagnosed by selective pulmonary artery angiography using the "stop flow" technique: the left pulmonary artery was occluded by inflating a balloon and a large bolus of dye was injected proximal to the balloon at a high flow velocity. These conditions, by increasing pulmonary artery pressure, increase the chances of imaging directly an ALCA. It also leaves the left pulmonary artery branches free of contrast medium and allows easier visualization of ALCA, mainly in the antero-posterior view. When an ALCA is injected from the pulmonary artery, left heart catheterization can be avoided. However, a false-negative result is to be expected in specific conditions and was observed in one of our patients. If pulmonary angiography fails to prove a ALCA, left heart catheterization remains mandatory to exclude the diagnosis.

Angiography↗

PubMed1987

Anatomic correction of simple transposition of the great arteries in 50 neonates.

From April 1984 to January 1986, anatomic surgical correction was performed in 50 newborn (2- to 23-day-old, mean 8 +/- 5 [SD]) infants with simple transposition of the great arteries. Before surgery, balloon atrial septostomy was performed in all patients, prostaglandin E1 was infused in 42, and left ventricular shape on a two-dimensional echocardiogram was considered "satisfactory" in 48. Surgery was performed in patients on cardiopulmonary bypass without cardiac arrest; the pulmonary artery was reconstructed by end-to-end anastomosis according to Lecompte's maneuver with a pericardial patch. In all but one patient coronary artery transfer was possible regardless of the distribution of these vessels. There were eight early deaths (16%), but only four (10%) of the last 41 patients treated died. There was one late death (2%) due to a secondary myocardial infarction caused by compression of the left coronary artery. Reoperation was successfully performed in two patients for supravalvar pulmonary artery stenosis. The only late medical complication was a transient episode of myocardial ischemia 6 months after surgery. The 41 late survivors were in excellent condition, were in sinus rhythm, and had a normal left ventricle 1 to 22 months after surgery (mean 7.2 +/- 5.4 [SD]). Aortic growth was normal; pulmonary artery supravalvar stenosis occurred in six patients (mild in four). We conclude that anatomic correction can be applied successfully in the first few days of life in newborns with simple transposition of the great arteries, regardless of coronary distribution.

Cardiopulmonary Bypass↗

PubMed1987

Redistribution of regional blood flow and oxygen delivery in experimental cyanotic heart disease in newborn lambs.

Redistribution of regional blood flow is an important compensatory response to acute hypoxemia which preserves oxygen delivery to the most vital organs. It is not known if this change in blood flow persists when hypoxemia is prolonged, as occurs in cyanotic congenital heart disease. Chronic hypoxemia was produced in newborn lambs by creating pulmonary stenosis and an atrial septal defect. Oxygen saturation was maintained at 60-70% of control for 2 wk. Distribution of cardiac output was then measured with radionuclide-labeled microspheres. As compared with control, chronic hypoxemia did not alter total cardiac output. Regional blood flow was redistributed, however, the pattern of this redistribution was different from that seen during acute hypoxemia. Myocardial and cerebral blood flows, which increase during acute hypoxemia, return to control levels during chronic hypoxemia. Renal, splenic, gastrointestinal, carcass, and skin blood flows remain decreased. Hemoglobin gradually increases so that after 2 wk of hypoxemia total systemic oxygen delivery returns toward control. However, oxygen delivery to all organs except the heart and brain is reduced. Thus, although cardiac output and total systemic oxygen delivery return toward normal during chronic hypoxemia, these measurements may not reflect important regional variations in blood flow and oxygen delivery. Decreased oxygen and substrate delivery to the gastrointestinal tract, liver, and carcass may account for the alterations of metabolism and growth seen in the newborn with cyanotic congenital heart disease.

Animals↗

PubMed1987

[Problems posed by percutaneous pulmonary valvuloplasty in children].

Percutaneous valvuloplasty with a balloon catheter was attempted in 41 young patients with pulmonary valve stenosis. There were 9 neonates (1 to 7 days), 6 infants (1.5 to 7 months) and 26 children (16 months to 17 years). The attempt failed in 8 cases, either because the balloon could not be inserted due to intravenous progression problems or to quasi-atresia of the orifice, or because serious accidents (air embolism in one patient, perforation of the infundibulum in another) forced us to abandon the procedure before dilatation. Failures mostly occurred in very young children: 7 out of 15 aged less than 1 year, 1 out of 26 older than 1 year. Dilatation was effective in 33 cases. Among 13 patients who had moderate stenosis with infra- or iso-systemic right ventricular systolic pressure (RVP) (mean: 70 +/- 13 mmHg) and modest ventriculo-pulmonary gradient (49 +/- 12 mmHg), there was only 1 failure due to coexistent biventricular myocardiopathy; success was immediate and complete in 8 cases, partial in 4 cases. Among 20 children presenting with tight stenosis with supra-systemic RVP (164 +/- 39 mmHg) and high ventriculo-pulmonary gradient (140 +/- 43 mmHg), there were 5 failures; success was partial in 8 cases, complete and immediate in 7 cases. Accentuation of the infundibular stenosis after dilatation was a frequent cause of failure, as we have shown by calculating the infundibular "reactivity index" on pre- and post-operative angiocardiograms. In such cases one may hope for spontaneous improvement, as was indeed subsequently observed in 2 of our patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1987

[Anti-arrhythmia efficacy of propafenone in children. Apropos of 30 cases].

Thirty children aged from 3 months to 20 years were treated with propafenone 250 to 650 mg/m2 divided into 2 to 4 daily doses, for a mean period of 14 months (range: 4 days to 5 years); 8 had chronic atrial tachycardia, 9 had junctional arrhythmia and 13 had ventricular arrhythmia. There were 17 good results (suppression of the arrhythmia), 7 fair results (good clinical effect but partial persistence of the arrhythmia) and 6 failures, either because the drug proved ineffective (3 cases) or on account of side-effects (3 cases). In the treatment of chronic atrial tachycardia propafenone seemed to be more effective than amiodarone in 3 cases and as effective as that drug in 2 cases. In junctional arrhythmia propafenone was certainly effective but unpredictably so (3 good results, 2 fair results, 4 failures). Among ventricular arrhythmias, ventricular tachycardia in bursts was the one which benefited most regularly from treatment with propafenone: the results in 8 patients were better than those obtained with other antiarrhythmic agents (class I drugs, beta-blockers, calcium antagonists); only amiodarone proved superior to propafenone in this type of arrhythmia. Despite a 27% incidence of side-effects, propafenone was generally well tolerated by the children, with no significant gastrointestinal disorders. No depressive effect on the myocardium was noted in 6 children with moderate heart failure well controlled by digitalis and diuretics. However, since overdosage may cause severe disorders of conduction with widened ventriculogram, we recommend regular ECG monitoring during the first 3 days of treatment at least: although there is little slowing down of sinus rate (12%) and little modification of the slow phase under treatment, serious toxicity is possible. Thus, propafenone is a drug that should be handled with caution, but it constitutes a major addition to the range of antiarrhythmic agents which can be used in paediatrics.

Adolescent↗

PubMed1987

[Apparently idiopathic primary myocardiopathies in children. The role of metabolic etiology].

Thirty-three children presenting with "primitive" cardiomyopathy observed from January 1984 to December 1985 underwent a protocol of investigations consisting of histo-enzymatic study of the deltoid muscle, metabolic studies (glucose, free fatty acids, lactate, pyruvate, 3-hydroxybutyrate, aceto-acetate, carnitine, amino-acids blood levels after a 15 hour-fast; urinary organic acids chromatography) and a study of the fatty acids oxidation in cultured fibroblasts. In all children cardiac involvement was predominant and had been the cause for hospitalization. Cardiomyopathies of the hypertrophic type have an early onset, most often are part of a complex picture of extra-cardiac involvement and frequently have a lethal evolution. On the contrary, hypokinetic dilated cardiomyopathies are most often isolated, have a later onset and a less severe course. In 2 cases, an early hypokinetic dilated cardiomyopathy evolved toward hypertrophy. Peripheral muscular involvement is very frequent (lipidosis, mitochondrial aggregates or specific aspects) (60% of cases) in dilated as well as hypertrophic types. A precise etiological diagnosis or a strong presumption was possible in 12 of 33 cases: 2 with hereditary deficiency of the fatty acids beta-oxidation, 1 carnitine systemic deficiency, 1 Friedreich ataxia, 1 central core disease, 1 coxsackie B1 myocarditis, 6 strong suspicions of respiratory chain deficiency.

Cardiomyopathy, Dilated↗

PubMed1987

[Trial of prevention of coronary aneurysm in Kawasaki's disease using plasma exchange or infusion of immunoglobulins].

Coronary aneurysms are present in 15-25% of cases of Kawasaki disease and are responsible for the morbidity and rapid mortality in this disease. We treated 20 children aged 20 +/- 16 months, less than 15 days (8 +/- 3.2) after onset of the disease, either by plasma exchange (7 exchange transfusions and one plasmapheresis) or by high dose intravenous gammaglobulins. No coronary anomalies or cardiac dysfunction prior to or after therapy (mean follow-up 8.3 +/- 4 months) was found. Tolerance to therapy was good and the course of the disease was arrested by exchange transfusions or shortened by gammaglobulin infusion. We conclude as have the Japanese, that this therapy is efficacious and safe, and should be initiated early.

Child, Preschool↗

PubMed1987

[Treatment by prostaglandin E1 of isolated coarctations in newborn infants with acute cardiac failure].

In neonates with isolated coarctation of the aorta presenting with acute neonatal heart failure refractory to classical treatment, emergency surgery is associated with a 30% death-rate. We rather suggest to add to treatment a perfusion of prostaglandin E1 in order to dilate the ductus arteriosus and thereby the aortic isthmus. This was performed successfully in 9 of 12 neonates aged 5 to 16 days: coarctation was relieved and heart failure disappeared. As soon as the left ventricle became hyperkinetic again (2 to 6 days later), prostaglandin was discontinued. Coarctation reappeared with either chronic heart failure (3 cases) or severe arterial hypertension (5 cases). Eventually one child recovered without surgery and the other 11 were operated on at an average age of 24 days, with only one death.

Alprostadil↗

PubMed1987

Intrauterine creation and repair of pulmonary artery stenosis in the fetal lamb. Weight and ultrastructural changes of the ventricles.

Fetal lamb experimental models were employed for intrauterine creation and repair of pulmonary artery stenosis. The study group was composed of 51 fetal lambs including 29 models of pulmonary artery stenosis and 22 control lambs. Gestational age was 89 days at creation of pulmonary artery stenosis. Fourteen fetal lambs (Group A) were studied after creation of the stenosis at 131 days of gestation and compared to normal age-matched control lambs. The systolic right ventricular pressure was significantly higher after creation of pulmonary artery stenosis (76.6 +/- 17.8 versus 50.3 +/- 23.5 mm Hg), but the systolic pulmonary artery pressure was unchanged. The mean right ventricular weight and the mean right ventricular/left ventricular weight ratio were significantly greater after pulmonary artery stenosis than in normal control animals. The transverse myocyte diameter was not modified by pulmonary artery stenosis, but on electron microscopic study the myocytes appeared mature. Ten lambs (Group B) underwent intrauterine repair of pulmonary artery stenosis at 131 days of gestation without cardiopulmonary bypass. The pulmonary artery was clamped and patched. Immediately after repair the right ventricular pressure fell significantly from 85.8 +/- 18.9 to 62.2 +/- 14.6 mm Hg. At birth, 7 +/- 6 days after repair, Group B was compared to Group C (unrepaired pulmonary artery stenosis, five fetuses) and to normal control lambs. The mean right ventricular weight and the mean right ventricular/left ventricular weight ratio were not statistically different in Group B and in the control group. There were no ultrastructural changes after intrauterine repair. We conclude that intrauterine creation of pulmonary artery stenosis causes right ventricular hypertrophy with more mature myocytes. Intrauterine repair of pulmonary artery stenosis is feasible without cardiopulmonary bypass and rapidly abolishes the preponderance of right ventricular weight over left ventricular weight.

Animals↗

PubMed1987

[Scimitar syndrome in infants. Physiopathology and therapeutic implications in 12 cases].

Twelve children, aged 6 days to 6 months (mean: 42 +/- 23 days) were diagnosed as presenting with the scimitar syndrome. In this syndrome, anomalous pulmonary venous drainage, hypoplasia of the right pulmonary artery and parenchyma, variety of "sequestrum" of the right pulmonary artery and parenchyma, variety of "sequestrum" of the right pulmonary base usually fed by subdiaphragmatic branches of the aorta are associated. Respiratory disorders were constant, severe in 8 cases. X-rays showed "dextro-cardia" and "hypoplasia of the right lung". Endocardiac investigation assessed the diagnosis and showed pulmonary arterial hypertension in 11 cases, with (5) or without (6) associated heart defect. One case with good tolerance remains under simple supervision; 4 were operated on from the associated lesions only and died; 7 took benefit of a simple surgical removal of the branches feeding the sequestrum, with one death and 6 successes. The poor prognostic significance of the sequestrum is thus indirectly demonstrated and the value of its devascularization is emphasized.

Cardiac Catheterization↗