Effects of Prostaglandin E1, prostacyclin, and tolazoline on elevated pulmonary vascular resistance in neonatal swine.
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Animals↗
Biomedical subjects
J M Neutze
Publications and source records attributed to J M Neutze.
Control of elevated pulmonary vascular resistance in neonatal swine with prostacyclin (PGI2).
Three groups of neonatal piglets were anesthetised and base-line hemodynamic measurements were made. The piglets were then subjected to hypoxia and hypercapnea to raise pulmonary vascular resistance (PVR) and further hemodynamic measurements were made over a period of at least 100 minutes. During the last 80 minutes of this period the control group received an infusion of 0.05M Tris buffer [the vehicle for prostacyclin (PGI2)], the second group received an infusion of 0.5 microgram/kg/min PGI2, and the third group received an infusion of 1.0 microgram/kg/min PGI2.
Animals↗
Postoperative evaluation of patients with tetralogy of Fallot repaired in infancy. Including criteria for use of outflow patching and radiologic assessment of pulmonary regurgitation.
The late hemodynamic and radiologic findings were good or excellent in 96 percent of 23 infants in whom tetralogy of Fallot was repaired with the use of profound hypothermia. These results encourage continuation of the policy of early repair rather than palliation in tetralogy of Fallot. The preoperative cineangiocardiographic assessment of the type and severity of the pulmonary stenosis accurately predicted the findings at operation and the type of repair required. In infants between 1 and 21 months of age and 3 and 10 kilograms in weight, a main pulmonary artery (MPA) diameter of less than 7 mm. was the cineangiocardiographic measurement most accurately predicting the necessity for an outflow patch across the pulmonary ring. Postoperative studies showed significant increases in the MPA and pulmonary ring diameters. A Method of cineangiocardiographic assessment of pulmonary incompetence is presented. Severe mechanical pulmonary incompetence in some patients produced mild hemodynamic effects by radiologic criteria.
Adult↗
The effects of some methyl prostaglandin derivatives on the ductus arteriosus of swine in vivo.
Three methylated analogues of prostaglandin E1 and E2 were examined for their ability to open the ductus arterious of neonatal piglets in vivo. Fifteen (S) 15 methyl prostaglandin E1 (15-Me PGE1), 15 (S) 1K methyl prostaglandin E2 (15-Me PGE2), and 16' 16' dimethyl prostaglandin E1 (16-diMe PGE1) all opened the ductus when given intravenously, intramuscularly or orally. The effects on ductal patency lasted four hours or more in many instances. Side-effects included apnea with intravenous and intramuscular dosages, and with high oral dosages of 15-Me PGE1. A transient drop in heart rate and blood pressure occurred with each dose. In one animal the ductus was kept open for 19 days with six-hourly intramuscular injections of 3 microgram/kg 15-Me PGE1. Transient sedation occurred with each dose. Death occurred on the 19th day and histological studies showed that the morphology of the ductus wall was similar to that seen in a two day old animal. These studies suggest that maintenance od ductal patency in the infant may be possible with oral administration of methyl prostaglandin derivatives.
Administration, Oral↗
Echocardiography in assessment of infants with complete d-transposition of great arteries.
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Angiocardiography↗
Effect of prostaglandins and some methyl derivatives on the ductus arteriosus.
In vitro studies showed that PGF2a constricted the ductus arteriosus of newborn animals, whereas PGEs produced dilatation. The finding that constriction could also be produced by c-GMP and dilatation by c-AMP raised the possibility that the PGs might produce their effects by altering the relative proportions of cyclic nucleotides in the ductus wall. Results of experiments with inhibitors of PG synthesis and with drugs which are known to interfere with the degradation of c-GMP and c-AMP accorded with this hypothesis. Angiographic studies in neonatal piglets showed that PGEs and PGAs were potent dilators of the ductus. Prostaglandin action was confirmed in infants with congenital heart disease who were dependent on ductus patency for survival. In those patients, PGs proved to be an extremely useful tool. Experimental studies are in progress in the hope of finding a PGE analog, active by the oral route, which may be suitable for the long-term treatment of patients.
Animals↗
Total anomalous pulmonary venous connection. Long-term results following repair in infancy.
Twenty-three infants, aged 5 days to 10 months, underwent repair of total anomalous pulmonary venous connection (TAPVC). Coronary sinus drainage was unusually common, accounting for 39 percent of the total. There were three early and four late deaths. Although the hospital deaths were related to perioperative errors, two of the infants appeared to have small left ventricles. Two late deaths in infants with coronary sinus drainage were due to obstruction to pulmonary venous return some distance proximal to the surgical anastomosis. All 16 survivors were well at last review, one after revision of his repair. Fifteen have undergone late reassessment, and one of these, also with coronary sinus drainage, showed evidence of pulmonary venous obstruction. Although the early survival rate is satisfactory, the late mortality rate has been significant and the high incidence of pulmonary venous obstruction in infants with coronary sinus drainage is of particular concern.
Brachiocephalic Veins↗
Serum digoxin levels in neonates, infants and children with heart disease.
Serum digoxin levels were measured in 53 neonates and infants receiving 18-22 microgram/kg/day (high dose) oral maintenance digoxin, and 44 neonates, infants and children receiving less than 18 microgram/kg/day (low dose) oral maintenance digoxin. In both groups, patients under four months of age had significantly higher serum digoxin levels than older patients, in the high dose group 2.6 ng/ml compared with 1.4 ng/ml and in the low dose group 2.2 ng/ml compared with 1.0 ng/ml. Correlation between digoxin dosage and serum level was weak and unaffected by blood urea level. Only two patients in the entire series showed toxic manifestations. Sixteen patients had serum digoxin levels measured before and after corrective cardiac surgery while receiving comparable dosages of digoxin. Despite lower serum digoxin levels postoperatively pulse rates fell significantly, illustrating the influence of changing haemodynamic status on the inter-relationships of digoxin dosage, serum levels and clinical response. Recommended dosage regimens are outlined.
Adolescent↗
The role of echocardiography in neonatal and paediatric cardiological diagnosis.
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Echocardiography↗
Calibration of densitometers for indicator dye dilution.
A systematic investigation was undertaken to determine which factors affect the calibration of a Gilford monochromatic densitometer used for recording indicator-dilution curves with indocyanine green. Calibration was not influenced by variation of withdrawal speeds from 6.4 to 20.6 cm3/min but varied with differing sampling systems. Variation in haemoglobin from 10 to 17.5 g-dl-1 or in haematocrit from 30 to 60% did not affect calibration. Calibration lines showed both curvature and hysteresis. The opitcal properties of indocyanine green were not affected by storage of diluted dye in the dark for 24 hours but were altered by the presence of contrast media used in angiography. No systematic error resulted from the substitution of stored ACD blood for patient's blood in calibration although random error was increased. Recommendations based on these findings are made for a simple calibration technique which avoids systematic error.
Blood Preservation↗
Palliation of cyanotic congenital heart disease in infancy with E-type prostaglandins.
Prostaglandin-E (PGE) infusions have been used in an attempt to increase ductal patency in 11 infants aged one to 99 days with cyanotic heart disease. PGE1 was used in nine infants and PGE2 in two. Five patients had pulmonary atresia, four extreme pulmonary stenosis, one Ebstein's anomaly and one simple transposition of the great arteries. All but the oldest infant showed a satisfactory increase in oxygen saturation (average 36%) attributed to dilatation of the ductus. The failure in one infant may have been due largely to hypoplasia of the left pulmonary artery. The only important side effect was apnea in one infant receiving PGE2. The efficacy of this form of treatment is confirmed in infants dependent on ductal patency for survival. PGE is an important asset in saving the lives of neonates requiring an aorticopulmonary shunt operation. The recommended starting dose is 0.1 mug/kg/min of PGE1 given by constant infusion.
Heart Defects, Congenital↗
Double outlet left ventricle. Morphology, cineangiocardiographic diagnosis and surgical treatment.
In double outlet left ventricle,both the pulmonary artery and the aortaarisefromthemorphologicleft ventricle. This paper presents the anatomic and cineangiocardiographic features of five patients who had this condition proved at surgery or autopsy. The condition of the first patient was incorrectly diagnosed as transposition of the great arteries with pulmonary stenosis and ventricular septal defect; the anatomic features were correctly interpreted at operation in 1966 and appropriate repair was made, but the patient died postoperatively. The condition of the other four patients was correctly diagnosed. The second patient had Ebstein's malformation of the tricuspid valve and hypoplastic right ventricle in addition to double outlet left ventricle; her condition was not considered operable. Two patients, one with visceroatrial situs solitus, concordant d-loop and dextrocardia, were surgically treated with good long-term results. The fifth patient died 2 years postoperatively and is the first patient reported to have double outlet left ventricle with visceroatrial situs inversus, a discordant d-loop and levocardia. The segmental approach to the classification and diagnosis of connection disorders is discussed and the radiologic criteria by which double outlet left ventricle may be diagnosed considered in detail. The importance of using the radiologic projection (usually left anterior oblique) that profiles the ventricular septum is emphasized because the diagnosis can be established only by delineating the relations of the origins of the great arteries to the ventricular septum. The surgical significance of other anatomic features, including the number, size and position of ventricular septal defects and conal malformations, is also discussed.
Adult↗
Studies on the effects of prostaglandins E1, E2, A1, and A2 on the dustus arteriosus of swine in vivo using cineangiography.
Prostaglandins E1, E2, A1, and A2 have been shown by cineaortography to open and dilate the ductus arteriosus in anesthetised piglets 3 to 6 hours of age. The dosage of PGEs required was 1 to 4 mug/kg/min. and of PGAs 20 to 40 mug/kg/min. The effect of PGEs faded within 20 minutes of stopping infusion but the effect of PGAs was still evident up to 45 minutes after stopping the infusion. Little effect was noted from hypoxia or from the addition of indomethacin to prostaglandin infusion. Side effects were not troublesome with the dosage employed but hypotension and apnea sometimes occurred at the onset of PGE infusions.
Animals↗
Repair of ventricular septal defect in the first two years of life using profound hypothermia-circulatory arrest techniques.
Ventricular septal defect repair had been performed in 57 infants ages 21 days to 21 months and under 10 kg in weight using profound hypothermia-circulatory arrest technics. Severe congestive heart failure was the indication for operation in all but two infants under 6 months of age, and in those under 3 months there was usually an associated moderate or large sized atrial septal defect or patent ductus arteriosus or a coarctation. In infants over 6 months controlled heart failure was accompanied by failure to thrive and often recurrent respiratory infections. The main indication for surgery in three infants was repeated severe respiratory infections and in 7 infants, ages 10-15 months, an elevation of pulmonary vascular resistance of 6 units M2 or more. There were two hospital deaths among the 49 infants without coarctation (ages 6 and 20 months) and two among the 8 with coarctation. Postoperative respiratory and other complications were uncommon. On late review there was no significant residual VSD amongst the 11 recatheterized patients. Psychometric studies in 19 children who had reached the age of three to four years gave no evidence of cerebral damage due to the circulatory arrest period. In view of these results palliative pulmonary artery banding is no longer performed for VSD in infancy unless there is a Swiss cheese septum or an associated severe coarctation.
Aortic Coarctation↗
The natural history of rheumatic aortic regurgitation and the indications for surgery.
A detailed review was made of 180 patients with severe aortic regurgitation of rheumatic origin. Of these patients, 110 underwent aortic valve replacement. Thirty-nine clinical and haemodynamic factors were studied in an attempt to define those associated with (1) death before surgery, (2) a higher incidence of complications and hospital mortality after surgery, and (3) an unsatisfactory longer-term result of surgery. Only heart failure, radiographic heart size, left ventricular hypertrophy, and ventricular premature beats were associated with death before surgery. No factor predisposed to surgical complications and only preoperative factors associated with an unfavourable result after surgery were advanced heart failure, cardiomyopathy, extreme cardiomegaly, and ventricular premature beats. It is concluded that the indications for operation are: a cardiothoracic ratio of greater than 0-60, or a history of heart failure combined with electrocardiographic evidence of extreme left ventricular hypertrophy. Operation may be safely postponed if these indications are not met, though the presence of ventricular extrasystoles or evidence of independent myocardial disease are further factors which should influence the decision.
Adolescent↗
Late dysrhythmias and disturbances of conduction following Mustard operation for complete transposition of the great arteries.
Between 1964 and 1971, 49 patients were discharged from hospital following atrial baffle repair for transposition of the great arteries. Electrocardiograms of 47 of these patients were available for review seven months to eight and a half years (average 31 months) after operation. Of the 46 patients in sinus rhythm prior to operation, 40 (87%) were in sinus rhythm with normal atrioventricular conduction when last seen. Four patients (8.7%) had benign supraventricular dysrhythmias: three were junctional, one was atrial. None was noted to experience rapid dysrhythmias. Two patients showed evidence of abnormal atrioventricular conduction. There were five late deaths but in only one of these patients was a dysrhythmia a possible factor. The effects of variations in caval cannulation, extent of excision of the atrial septum and placement of the baffle suture line on the rhythm present at last review were examined. To preserve sinus rhythm it appears necessary to avoid surgical trauma in the vicinity of both the sinus node and the A-V node. Preservation of the internodal tracts appears less important. It is uncertain whether the 'sinus' rhythm seen after operation originates in the sinoatrial node but the rhythm is functionally similar.
Arrhythmias, Cardiac↗
Late postoperative hemodynamic results and cineangiocardiographic findings after Mustard atrial baffle repair for transposition of the great arteries.
Forty-nine patients with transposition of the great arteries who underwent a Mustard atrial baffle repair between 1964 and 1971 were assessed late postoperatively. There have been five late deaths: two related to baffle obstruction, two from noncardiac causes, and one sudden and unexpected. Hemodynamic data were available in 42 patients and autopsy in four. Obstruction of the lower venous channel was not encountered. Three patients had severe obstruction of the upper venous channel and in four there was mild restriction. Two patients had severe pulmonary venous obstruction resulting in late death; mild asymptomatic obstruction could not be excluded with certainty in six patients. Tricuspid incompetence was infrequently encountered in patients with an essentially intact ventricular septum. Left ventricular outflow tract obstruction was found in eight patients. In three it was present after satisfactory but incomplete surgical relief and in five it had not been recognized prior to operation. In only one of the latter patients was the obstruction important. Seventeen patients were operated on prior to one year of age. While baffle obstruction was confined almost entirely to these patients, the five youngest patients, aged one to nine weeks at operation, had adequate pulmonary and caval compartments at restudy two to three years later.
Angiocardiography↗
The pulmonary vascular bed in patients with complete transposition of the great arteries.
Histological material obtained at autopsy from 35 patients over three months of age with complete transposition of the great arteries (TGA) was examined. Two of six patients less than a year of age with an intact ventricular septum and closed ductus arteriosus were found to have pulmonary vascular changes of at least grade 3 severity; in addition, two of seven patients with a large ventricular septal defect in this age group showed changes of similar severity. The reported low incidence of marked pulmonary vascular changes in patients with only an interatrial communication dying during the first year of life would appear to be due in part to the high proportion of cases less than three months old in whom there was not sufficient time for such changes to develop. Although the incidence is not as high as that found beyond a year of age, it is sufficiently high to influence the management of infants beyond three months of age. Hemodynamic studies were performed following atrial baffle repair in 34 patients. All but one of the 16 patients operated upon prior to two years of age had a pulmonary arteriolar resistance (Rpa) less than 3 units M2 at the time of review, including three with a large communication at ventricular or great vessel level who underwent surgery before two months of age. Repair at an older age did not preclude a low Rpa on follow-up, but in 11 of the 18 patients who were two or more years of age at the time of repair it was greater than 3 units M2. None of these latter patients had a large ventricular septal defect or patent ductus arteriosus. Comparison of postoperative hemodynamic data with autopsy studies would suggest that advanced pulmonary vascular disease is associated with earlier death among patients with complete transposition of the great arteries.
Cardiac Output↗