[Atresia or congenital stenosis of the left coronary ostium. Myocardial revascularization in 5 children]

Five patients, 3 months to 13 year old with atresia (4) or stenosis (1) of the left coronary artery underwent myocardial revascularisation at Marie Lannelongue Hospital. The preoperative symptoms were dominated in one case by cardiac failure due to myocardial infarction and in the other cases by effort angina with syncope. The operative technique of revascularisation in one case was angioplasty with enlargement of the left main coronary artery with a patch and, in the others, bypass graft of the left coronary artery with the left internal mammary artery. All 5 patients survived surgery and are asymptomatic with a follow-up of 6 months to 7 years. Control coronary angiography confirmed the patency of the different procedures of myocardial revascularisation. In 3 children, exercise electrocardiography was normal. Myocardial revascularisation of a child with a congenital stenotic abnormality of the left coronary network is possible, the technique of which depends on the diameter of the left main stenosis when the vessel is absent or atresic, left internal mammary artery bypass graft is the only solution. When the left main coronary is stenosed but patent, direct reconstructive surgery is an interesting alternative.

[Comparison of long-term results of arterial switch and Senning procedure in transposition of great vessels with intact ventricular septum]

One hundred and five survivors after the 30th day of complete cure of transposition of the great arteries with intact ventricular septum between 1980 and 1985 were followed up. Fifty-four had an arterial switch (AS) in a single stage at an average age of 10 +/- 9 days and 51 had Senning's procedure (S) at an average age of 4 +/- 2.5 months. The average follow-up (97% of patients) was 5.8 +/- 1.1 years for the AS group and 9.3 +/- 2.3 years for the S group. The actuarial survival at 5 years was 100% in the AS group and 85.8% in the S group (p < 0.01) (8 late deaths). In the AS group, 3 patients were reoperated for stenosis of the pulmonary artery and, in the S group, 4 patients underwent 6 reoperations. All but 3 patients in the S group and all but 1 patient in the AS group are in functional Class I of the NYHA classification. Doppler echocardiographic studies have shown mild to severe dysfunction of the systemic ventricle in 2% of the AS group and 26% of the S group (p < 0.001). Holter monitoring, performed in 70% of patients in the S group showed sinus node dysfunction in 60% and sinus rhythm in 40% of cases. In conclusion, good functional results were observed at over 5 years in both groups. However, the absence of late mortality and the minimal incidence of systemic ventricular dysfunction in the AS group confirm the authors' choice of indication of arterial switch for the treatment of transposition of the great arteries with intact ventricular septum.

Metabolic effects of propofol and flunitrazepam given for sedation after aortic surgery

Sixteen patients who had undergone abdominal aortic surgery were allocated randomly to receive either propofol (total dose 3.2 (SEM 0.3) mg kg-1 h-1) or flunitrazepam (total dose 15 (2) micrograms kg-1 h-1) for 16 h after operation. Metabolic effects of sedation were assessed using a Deltatrac metabolic monitor. Initiation of sedation induced a 25% decrease in VO2 in both groups. The decrease was about 40% at 16 h. VO2 increased within 30 min after discontinuation of propofol and stabilized at values considerably less than the immediate postoperative value. A similar but slower increase was noted with flunitrazepam. While the propofol loading dose reduced the Buffington index and should therefore be avoided, no cardiovascular side effects were noted with the maintenance infusion. Weaning from ventilatory support was achieved within 15 (2) min and 264 (108) min after discontinuation of propofol and flunitrazepam, respectively.

Properties of motor units after immobilization of cat peroneus longus muscle

Changes in contractile properties of cat peroneus longus motor units were studied 2, 5, and 8 wk after selective immobilization of this muscle, which was achieved by fixing the distal tendon of the peroneus longus to the fibula either at the muscle minimal physiological length ("short" length) or at the length for a 90 degree ankle joint ("neutral" length). In each muscle, 75-90% of the units [slow (S), fast resistant to fatigue (FR), fast intermediate (FI), and fast fatigable (FF)] were studied. Immobilization elicited a permanent decrease in tetanic force developed by single motor units, which was larger for resistant-to-fatigue units (S, FR). In most instances this decrease was not related to the immobilization length. In all units, twitch contraction and half-relaxation times underwent a transient increase, the extent and time course of which were influenced by immobilization length. The relationship between the frequency of motor units activation and the ratio of unfused to maximal tetanic force was studied. For fast units, there was a transient shift of the relation toward low frequencies after 2 and 5 wk of immobilization at neutral and short length, respectively.

Maximum shortening speed of motor units of various types in cat lumbrical muscles

1. Isotonic shortening of cat superficial lumbrical muscles was studied during maximal tetanic contractions of single motor units of identified types. For each motor unit, the maximal speed of contraction, Vmax, was determined by extrapolating to zero the hyperbolic relation between applied tension and speed of shortening. 2. The maximal speeds of shortening of motor units formed a continuum with the highest velocities observed for the fast fatigable motor units and the lowest for the slow motor units. 3. On average, the maximum speed of shortening increased with the tetanic tension developed by the motor units. 4. In motor units with isometric twitch contraction times less than 35 ms, these times showed a significant inverse correlation with Vmax. Progressively longer contraction times were associated with rather small changes in Vmax. 5. The implications of these findings on the speed of muscle shortening during motor-unit recruitment are discussed.

Incidence of non-driving excitation of Ia afferents during ramp frequency stimulation of static gamma-axons in cat hindlimbs

1. The aim of this investigation was to identify static gamma-axons which do not drive any Ia afferents at any stimulus frequency in any spindle which they supply, and to determine their occurrence in various hindlimb muscles (peroneus tertius, brevis, longus and tenuissimus). 2. Ia responses to static gamma stimulation were classified as 'non-driven' when the discharge did not follow the stimulation frequency, or its subharmonics, at any time during a linear increase in stimulus frequency up to 150 Hz lasting 2-3 s, and when tested at two muscle lengths--except in the tenuissimus muscle. In almost all experiments, cross-correlograms were used in addition to evaluate the percentage of these 'non-driven' responses in which a time-locking of discharge to stimulus pulses was obscured by irregularity of the Ia discharge. 3. In 104 spindles, out of 347 responses to stimulation of single static gamma-axons 332 (93%) could be characterized, and of these, 57% (183) were of the non-driven type. The mean number of static gamma effects characterized per spindle was 4.1 (fourteen experiments). In the large majority of spindles (79%, 82 out of 104) at least one response was of the non-driven type. 4. Of the static gamma-axons studied 16% were called 'non driving' ('ndr' gamma s-axons) because they elicited non-driven effects, and since they had the same qualitative effect consistently in all spindles whose discharge was modulated by stimulating them they were called specific 'ndr' axons. If axons with non-driven effects, but acting on one spindle were included in the 'non-driving' category the proportion was 23%. Of spindles tested 63% were innervated by at least one 'ndr' axon. 5. Absence of Ia driving during ramp frequency stimulation of gamma s-axons has been equated with selective bag2 contraction. All the non-driven responses identified in this study cannot be attributed to exclusive bag2 involvement because the total number of 'ndr' responses was too high. In fact, in the isolated spindle preparation bag2 and chain co-contraction were shown to elicit non-driven responses, so chain contraction is not detected reliably in all experimental conditions. Possibly chain fibre contraction is sometimes too weak to dominate the response, or can be of a non-driving character.(ABSTRACT TRUNCATED AT 400 WORDS)

[Neonatal heart transplantation. First results]

Two 5- and 17-days old neonates with hypoplastic left heart syndrome respectively underwent orthotopic heart transplantation. The donor-recipient weight ratio was +58 percent and +88 percent; ischemic time was 144 and 167 min. The immunosuppressive protocol included thymoglobulin during the induction period and a classical 3-drug therapy, with a rapid tapering off of prednisone over 3 weeks. No infectious complication was observed; each infant experimented one episode of acute rejection, successfully treated with prednisolone. Forty-three months and 10 months later, the 2 children are doing well, with normal renal function and normal growth. No late rejection episode was observed. Heart transplantation in neonates is feasible, the short-term and mid-term results are good. Despite important ethical problems, heart transplantation represents a great hope for neonates with inoperable congenital heart defects.

[Criteria for choice of the donor in heart transplantation in adults]

Among 66 consecutive adult heart transplant recipients operated on from January 1988 to October 1991, 11 experimented early graft dysfunction (4 of them died). Mean donor's age was 37.4 +/- 11 years; 9 patients were older than 50 years; 85 percent of donors received dopamine. Were found without any significant influence on early graft function: donor's age, weight mismatch, duration of donor's intensive care, dose of dopamine administered, external cardiac massage and relative hemodynamic instability, and ischemic time. Conversely, a history of chronic alcoholism in the donor is of pejorative significance, which is not without consequences in view of the current scarcity of donors.

Comparison of skeleto-fusimotor innervation in cat peroneus brevis and peroneus tertius muscles

1. The skeleto-fusimotor or beta innervation was compared in cat peroneus brevis and peroneus tertius muscles, which differ in their composition of fatigue-resistant motor units; the slow (S) units predominate in brevis and the fast units (FR) in tertius. 2. In four brevis muscles, of thirty-four beta-axons (from a total of 114 axons supplying extrafusal muscle fibres) twenty-nine were dynamic (beta D) and only five static (beta S). In contrast, in three tertius muscles, of twenty-five beta-axons (from a total of 82 axons) twelve were static and thirteen dynamic. 3. In a population of thirty-five brevis and thirty tertius spindles, the proportion of beta D-innervated spindles was greater in the brevis (68.5%) than in the tertius (50%) whereas that of beta S-innervated spindles was greater in the tertius (40%) than in the brevis (17.1%). In a population of thirty-two brevis and twenty-seven tertius spindles in which the presence of bag1 fibres was deduced from the existence of a dynamic innervation, the proportion of spindles innervated by beta D-axons was 80% in the brevis and 62% in the tertius. 4. In both muscles, the number of beta D effects was greater than that of beta S effects. beta S-axons were rarely found to supply more than one spindle whereas beta D-axons supplying more than one spindle (up to four) were common. Spindles were often coinnervated by beta D- and beta S-axons.(ABSTRACT TRUNCATED AT 250 WORDS)

[Percutaneous mitral valvulotomy: comparison of 2 techniques in 100 matched-pair patients]

The results of percutaneous mitral valvulotomy by the Double Balloon and the Inoue Balloon were compared in 100 patients referred to Marie-Lannelongue Hospital between 7/11/86 and 8/3/91, paired for age, sex and echocardiographic features of the mitral valve. The transvalvular diastolic pressure gradient at catheterisation or Doppler echocardiography decreased significantly and similarly with the two techniques: -65 +/- 19% versus -64 +/- 15% (p = 0.10) and -66 +/- 22% versus -58 +/- 23% (p = 0.20) for the Double-Balloon and the Inoue Balloon techniques respectively. Similarly, the mitral valve surface area measured by planimetry during echocardiography or calculated from the Gorlin formula increased by 0.9 +/- 0.39 cm2 with the Double Balloon and by 0.88 +/- 0.32 cm2 with the Inoué Balloon (p = 0.91) or by 0.98 +/- 0.62 cm2 versus 0.87 +/- 0.45 cm2 (p = 0.42). The number of commissures opened was the same with both techniques. The evolution of mitral regurgitation after dilatation was similar: stable or less severe in 61% dilated by the Double Balloon and 68% by the Inoue Balloon; aggravation by more than one grade in 7 and 5% respectively (p = 0.17). Complications were rare and comparable with both techniques. The results with the two methods were the same if patients with an optimal indication and those with more severe mitral valve disease were considered separately. The rapidity and simplicity of percutaneous mitral valvulotomy with the Inoué Balloon make it the technique of choice.

Early palliation of univentricular hearts with subaortic stenosis and ventriculoarterial discordance. The arterial switch option

The optimal Fontan-type operation greatly depends on appropriate initial palliation. Several surgical techniques have been used in infancy to palliate patients with univentricular hearts, ventriculoarterial discordance, and subaortic stenosis. The two most common are pulmonary artery banding and Damus-Norwood procedures. Palliative arterial switch operation is another surgical option that was used in this early series of seven infants. The principle of this operation is to "switch" the subaortic obstruction into a subpulmonary obstruction; the coronary artery relocation on the large pulmonary trunk creates a harmonious aortic root and the connection of the rudimentary ventricular chamber to the pulmonary artery trunk creates a natural protection of the pulmonary vascular bed through the restrictive bulboventricular foramen. Seven infants with univentricular hearts, ventriculoarterial discordance, and subaortic stenosis underwent a palliative arterial switch operation. All infants had an associated aortic arch obstruction of various degrees, including one with interrupted aortic arch, five with coarctation with severe arch hypoplasia, and one with isolated arch hypoplasia. There were three with double-inlet left ventricle, three with tricuspid atresia, and one with transposition of the great arteries with ventricular septal defect and severe right ventricular hypoplasia. The subaortic obstruction was patent at birth in five patients who underwent a palliative switch operation in the first 2 months of life, and rapidly occurred following a previous neonatal pulmonary artery banding associated with arch repair in two patients who underwent a switch operation at 5 and 8 months of age, respectively. The operation includes aortic arch repair without prosthetic material, an atrial septectomy, and the arterial switch. An associated pulmonary shunt was required in five patients and a pulmonary artery banding in one. There was one early death in a patient with [S,L,L] anatomy and congenital atrioventricular block, leading to an early mortality of 14% (95% confidence limits: 1% to 28%). There was one late death. Four survivors are waiting for a Fontan-type procedure, and one survivor had satisfactory right ventricular growth. Early palliative arterial switch operation offers several advantages: reconstruction of a harmonious aortic root, natural protection of the pulmonary bed through the restrictive bulboventricular foramen, prevention of deleterious myocardial hypertrophy, and arch reconstruction without the introduction of a foreign material. This aggressive technique may provide a satisfactory palliation in infants with univentricular hearts and ventriculoarterial discordance, when the bulboventricular foramen/aortic anulus ratio is less than 0.8 or when the subaortic stenosis is severe enough to be associated with an arch obstruction.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult heart transplantation: adverse role of chronic alcoholism in donors on early graft function

Because of the increasing shortage of heart donors, selection criteria have been gradually extended. The purpose of this study was to determine the donor-related factors implied in early graft dysfunction and to define new selection criteria. The 70 consecutive adult patients who underwent heart transplantation in our institution between January 1988 and February 1992 were retrospectively studied. Mean donor age was 38 +/- 11 years (10 donors were more than 50 years of age; two donors were more than 60 years of age). Mean ischemic time was 130 +/- 39 minutes. An important proportion of donors (20%) had a history of chronic alcoholism. Thirteen patients experienced immediate graft dysfunction; five of them died within the first operative month. The different parameters studied, which were found to have no significant influence on the early graft function, were the age of the donor, the duration of inotropic support and the dose administered, a relative hemodynamic instability, resuscitation maneuvers, chest trauma, and weight mismatch between donor and recipient. Ischemic time was significantly longer in patients who died of cardiac dysfunction (p < 0.05). Chronic alcoholism in the donor was a very detrimental factor: 54% of patients who had early graft dysfunction versus only 12% of patients who had immediate normal graft function had received a graft from an alcoholic donor (p = 0.003). Excluding such alcoholic donors or reserving them for critically-ill recipients, with an increased risk of early graft dysfunction would be preferable.

[Total cavo-pulmonary bypass. Short-term results]

In order to reduce the complications of the Fontan procedure, 2 techniques of total cavopulmonary connection using a right intra-atrial baffle (Pugas' technique, 19 patients), and a modified de Kreutzer (19 patients) were assessed in 38 consecutive patients operated between November 1980 and November 1991. All patients had complex cyanotic congenital heart disease: tricuspid atresia (13), single ventricle (12), hypoplasia of one of the two ventricles (8), pulmonary atresia with an intact septum (5). The average age was 5.8 +/- 5.6 years (range 1 to 30 years), the weight was 18 +/- 11.7 kg (range 8 to 59.7 kg). Six patients (15.8%) died, 4 of whom (10.5%) in the operative period. Five of these deaths were related to extremely high right heart pressures without any technical fault, and the other to thrombosis of the conduit in a patient not taking anticoagulants. Two immediate and 10 secondary reoperations were necessary. All 3 patients who had disconnection of the anastomosis because of high right heart pressures died. The postoperative course was often difficult: right heart failure (63%), pleural effusion (57%), and pericardium effusion (13%). Of the risk factors analysed, age had no influence on postoperative outcome. The two poor prognostic factors were: presence of atresia or hypoplasia of the systemic atrioventricular valve (mortality 42.8% versus 6.5%, p = 0.05 and prolongation of the hospital period: 39.5 +/- 32 days versus 21 +/- 11 days, p less than 0.05) and previous banding (reoperation rate 62.5% versus 16.6%, p less than 0.05, and longer stay in the intensive care unit and hospital period).(ABSTRACT TRUNCATED AT 250 WORDS)

[Peroperative evaluation of pulmonary vascular resistance by cavo-pulmonary bypass. Value of atrio- and cavo-pulmonary diversions]

Immediate and long-term results of the Fontan procedure depend on the value of the pulmonary vascular resistance. This parameter cannot always be quantified accurately during preoperative evaluation. Cavo-pulmonary bypass using an extra corporeal circulation allowed simulation a Fontan procedure in 5 patients, and prediction of the pressure changes in the pulmonary artery and the systemic atrium according to the pulmonary to systemic resistances ratio. This technique could be valuable in border line cases for deciding on the optimal therapeutic solution.

Measurement of trazodone in plasma and brain of rat by capillary gas chromatography with a nitrogen-selective detector

A specific and highly sensitive method for the measurement of trazodone in plasma and brain of rat is presented. The compound and the internal standard were extracted from alkalinized samples with hexane and analysed by capillary gas chromatography with nitrogen-selective detection. The method was demonstrated to be accurate and precise. The limits of determination were 2 ng/ml for plasma and 24 ng/g for brain, which makes this procedure suitable for pharmacokinetic analysis.

Surgical management of isolated multiple ventricular septal defects. Logical approach in 130 cases

From January 1980 through September 1990, 130 children underwent surgical closure of isolated multiple ventricular septal defects (mean age 14 +/- 18 months, mean weight 7.0 +/- 4.4 kg). Sixty-one were less than 1 year of age. Sixty-one children had pulmonary protection, 51 had pulmonary artery banding, and 10 had pulmonary valve stenosis. All other patients had severe pulmonary hypertension (mean systolic pressure 75.7 +/- 20.5 mm Hg and already disabling heart failure (New York Heart Association classes III and IV). The surgical management was based on the location of the defects and the ventricular dominance that were assessed preoperatively and intraoperatively. Midtrabecular ventricular septal defects were always centered by the moderator band and were therefore divided into low trabecular, midtrabecular, and high trabecular defects. The perimembranous septum was involved in 102 patients, the trabecular in 121, the inlet septum in 12, and the infundibular septum in 9. Fifty patients had the "Swiss cheese" form of the lesion. Closure of the ventricular septal defects included Dacron patch and mattress sutures. They were always first approached through a right atriotomy, which was sufficient for complete repair in 82 patients. In midtrabecular ventricular septal defects, section of the moderator band (n = 24) allowed closure of all the defects with a single Dacron patch. In 48 patients a right atriotomy and a right (n = 32) or left (n = 14) (particularly for low trabecular ventricular septal defects) or both right and left (n = 2) ventriculotomies were necessary to secure the repair. The hospital mortality rate was 7.7% (10 patients). The causes of deaths were residual ventricular septal defect (n = 5), pulmonary hypertension (n = 2), hypoplastic right ventricle (n = 1) and left ventricle (n = 1), and myocardial infarction (n = 1). Among eighteen survivors with residual ventricular septal defect, six were reoperated on; there were two deaths. A permanent pacemaker was necessary in four patients. Low trabecular ventricular septal defects and left ventriculotomy were significant risk factors for morbidity (death, residual ventricular septal defect), p less than 0.01. At 7 years of follow-up, 90% of survivors were in New York Heart Association class I. Actuarial survival and freedom from reoperation at 7 years were 89.6% and 87.5%, respectively.

Liver factors involved in drug metabolism in experimentally infected rats: deleterious effect of ornithine α-ketoisocaproate

This study was designed to determine the effect of ornithine alpha-ketoisocaproate (O-KIC), a compound reducing muscle protein breakdown in physiological conditions, on liver factors involved in drug metabolism in rats with acute retrograde pyelonephritis. 91 rats were assigned to 7 groups differing in the level of food intake, induced infection, and the treatment by O-KIC (168 mg/kg bw/day). Rats were killed on the third day. O-KIC increased nitrogen balance and weight gain in controls, but not in malnourished infected or non-infected rats. Liver glutathione was significantly reduced by O-KIC in malnourished infected and non-infected rats. Though O-KIC induced a rise in liver microsomal proteins in control and infected animals, it decreased cytochrome P-450 in controls, and aminopyrine demethylase in both control and infected groups.

[Early failure in kidney transplantation]

Parameters of early failure in kidney transplantation have been analyzed from 507 transplantations with transplant loss in the first month, selected among the 7541 cadaveric kidney transplantations performed in France between 1985 and 1989. These failures represent 6.7 percent of the population transplanted over this period of time, 68.6 percent of the failures that occurred in the first 3 months post-grafting, and 47 percent of the total number of the first year failures. Comparing patients with and without transplant failure in the first month, sex of the donor and the recipient, ABO group of the donor and the recipient, origin of the kidney, cold ischemia time, HLA compatibility, dialysis duration, number of previous transplantations, showed no influence on the occurrence of early failure. Three parameters appeared to be significant risk factors: donor's age less than 5 years, P = 0.00001; recipient's age less than 5 years, P = 0.05; pregraft immunization, P = 0.002. Furthermore, multifactorial analysis showed that the absence of HLA compatibilities between donor and recipient in hyperimmunized patients also has a significant influence on early graft loss. However, comparison of these same parameters in patients with transplant failure within the first month and between 2 and 12 months post-grafting revealed that the influence of these 4 significant parameters is longstanding and that none of them is specific of the precocity of graft loss.

Anatomic repair of Taussig-Bing hearts

From 1978 through 1990, 27 consecutive patients underwent anatomic repair of Taussig-Bing heart (TBH) malformation. Group 1 (seven patients) underwent intraventricular repair by rerouting of the left ventricular blood stream through a tunnel patch from the ventricular septal defect (VSD) to the aorta. Group 2 (20 patients) underwent an arterial switch with VSD closure. Indications for each type of repair were based on the following criteria: when the great vessel relation is more or less anteroposterior, repair is performed at the arterial level; when side by side, the minimal tricuspid pulmonary valve distance is evaluated; if less than aortic valve diameter or if there are abnormal tricuspid chordae, repair is performed at the arterial level; if greater, pulmonary artery banding is performed in order to wait until suitable weight for intraventricular repair. The mean age at operation was 13.2 months. Coarctation of the aorta was present in 12 patients, abnormal tricuspid chords in eight, and subaortic stenosis in seven. The great vessels were in D-transposition in 12 patients, and they were side by side in 15. Seventeen patients underwent previous palliative surgery. Early (two patients, 7.4%) and late (two patients, 8%) mortality rates were related in group 1 to subaortic stenosis and in group 2 to myocardial infarction. Mean follow-up of 40 +/- 24 months was achieved in 22 survivors. They were all in New York Heart Association (NYHA) class I, without medication. Actuarial survival and freedom from reoperation rates were, respectively, at 5 years 73 +/- 14.6% and 58 +/- 13% (70% confidence limits [CL]).(ABSTRACT TRUNCATED AT 250 WORDS)