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Biomedical subjects

L V Fong

Publications and source records attributed to L V Fong.

At least 19 recordsLinked to original sources
PubMed1994

Study of low dosage prostaglandin--usages and complications.

Low dosage intravenous (< 0.01 micrograms.kg-1.min-1) and oral prostaglandin E have been reported to produce fewer complications than higher intravenous doses in the ductal manipulation of congenital heart disease. Over a 3-year period 34 patients were treated with low dosage intravenous or oral prostaglandin. Eighteen (53%) had complications associated with this treatment with 14 having more than one complication. Major complications occurred in nine neonates: necrotising enterocolitis (7), apnoea/bradycardia (5), convulsions (1), haemorrhage (1), and resulted in a change of management. This study therefore concludes that the high incidence of complications is similar with both low and high dosages of intravenous and oral prostaglandin. The use of prostaglandin in any form deserves caution.

Administration, Oral↗
PubMed1992

Diagnosis of cerebral arteriovenous malformation by colour Doppler examination.

A newborn presented in congestive cardiac failure, and colour Doppler ultrasonography confirmed a large aneurysm of the vein of Galen. The two-dimensional cranial ultrasound appearance was not diagnostic but colour Doppler examination highlighted the marked vascular abnormalities. The colour Doppler appearances were dramatically altered following coil embolisation of the vein of Galen. Colour Doppler examination is the technique of choice for diagnosis and follow-up of this unusual condition.

Echoencephalography↗
PubMed1991

Double aortic arch, tetralogy of Fallot with pulmonary atresia and atrioventricular septal defect.

A double aortic arch is usually an isolated abnormality. We describe a case with a previously undescribed combination of tetralogy of Fallot with pulmonary atresia, complete atrioventricular septal defect, and left patent arterial duct in association with a double aortic arch. A complete diagnosis was made by echocardiography. Meticulous suprasternal echocardiography must be employed to avoid overlooking an unsuspected aortic arch abnormality.

Abnormalities, Multiple↗
PubMed1991

Cardiac arrhythmias after surgical correction of total anomalous pulmonary venous connection: late follow-up.

Sixteen patients (10 males and six females) aged 7 months to 20 years, who had undergone surgical repair in the first year of life for total anomalous pulmonary venous connection (TAPVC), underwent assessment of cardiac rhythm by 24-h electrocardiogram (ECG) monitoring, nine of them also had maximal exercise treadmill tests, 3 months to 19.5 years after surgical repair. No patient had symptoms of an arrhythmia and the resting ECG was normal in all except one who had occasional single supraventricular ectopic beats. But on 24-h ECG monitoring significant arrhythmias were recorded in six of the 16 patients, including supraventricular tachycardia (three patients), bradyarrhythmia (two patients), sick sinus syndrome (two patients), and multiform supraventricular and ventricular ectopic beats (two patients). Five of these six patients were assessed more than 6 years after surgery. An inappropriate chronotropic response was seen on maximal exercise treadmill testing in four patients; three of them had arrhythmias previously recorded by 24-h ECG monitoring. Our observations show that significant arrhythmias may occur in asymptomatic patients long after TAPVC correction, and we therefore recommend long-term follow-up of these patients, even if they are asymptomatic.

Adolescent↗
PubMed1991

Late noninvasive evaluation of cardiac performance in mildly symptomatic older patients with Ebstein's anomaly of tricuspid valve: role of radionuclide imaging.

Ten patients 8 to 54 years of age with isolated Ebstein's anomaly of the tricuspid valve were evaluated by electrocardiography, maximal exercise treadmill testing, 24 h electrocardiographic (ECG) monitoring, echocardiography and rest radionuclide imaging of the left ventricle. The patients presented after the 1st year of life and had not undergone surgical intervention. All except one were in functional class II. No patient had preexcitation on the surface ECG, but abnormal tachyarrhythmias or bradyarrhythmias were seen in five patients on 24 h ECG monitoring. Subnormal exercise performance was observed in five patients. Echocardiography demonstrated typical variable tricuspid valve displacement and paradoxic interventricular septal motion. Left ventricular end-diastolic dimensions were normal in all patients, but posterior wall motion was reduced in two. Moderate to severe tricuspid regurgitation with a Doppler jet velocity less than 2.5 m/s was demonstrated in eight patients. Left ventricular radionuclide scintigraphy revealed a subnormal ejection fraction (less than 50%) in 5 of 10 patients; these 5 had previously shown suboptimal exercise performance. The two youngest patients (less than 15 years) had no arrhythmia, normal exercise performance and normal left ventricular ejection fraction. There was no correlation between the degree of tricuspid valve displacement or regurgitation and the presence of rhythm disturbance, exercise performance or radionuclide left ventricular function. Late evaluation of patients with Ebstein's anomaly may demonstrate significant unsuspected abnormalities in cardiac rhythm, exercise performance and left ventricular function. Radionuclide scintigraphy is a useful noninvasive technique for assessing left ventricular dysfunction in these patients.

Adolescent↗
PubMed1991

The early and long-term results of surgery for coarctation of the aorta in the 1st year of life.

The cases of 110 infants less than 1 year of age, who had surgical repair for coarctation of the aorta between June 1974 and February 1988, were analysed. Three groups of patients were identified. In group 1 there were 39 patients with isolated coarctation. In group 2 there were 25 infants with additional ventricular septal defects (VSD), while in group 3 there were 46 infants with other associated congenital cardiac defects. Repair was performed using the subclavian flap aortoplasty (SFA) procedure in 83 patients, resection with end-to-end anastomosis (EEA) in 23, patch aortoplasty in 3 and Goretex tube bypass in 1. Twenty-eight patients had simultaneous pulmonary artery banding and one concomitant closure of the VSD. The overall early mortality rate was 8.2% (5.1% in group 1, 0% in group 2, and 15.2% in group 3). Age at operation (under 1 month, p = 0.04) and other associated cardiac anomalies (p = 0.03) increased early mortality significantly. There were 11 late deaths (10.8%) among 101 patients followed from 1 to 15 years (mean 5.3 years). Twelve patients underwent further surgery for recoarctation, eight of them within 11 months. A further 11 patients currently have a Doppler gradient across their coarctation site of more than 20 mmHg, but have not undergone further surgery to the coarctation repair site.

Anastomosis, Surgical↗
PubMed1991

Gerbode ventricular septal defect following endocarditis.

A Gerbode defect is a ventricular septal defect communicating directly between the left ventricle and right atrium. There has been some debate about the existence of such an entity. We present the case of a previously healthy 15-year-old boy who developed bacterial endocarditis following ear piercing and was subsequently found to have a defect between the left ventricle and right atrium, which was successfully repaired surgically.

Adolescent↗
PubMed1991

Identification of anomalous origin of one pulmonary artery from ascending aorta by two-dimensional and colour Doppler echocardiography.

The anomalous origin of the right pulmonary artery from the ascending aorta in a neonate was diagnosed by two-dimensional and colour directed Doppler echocardiography. An anomalous arterial vessel coursing towards the right lung originated from the posterolateral aspect of the ascending aorta. It could be visualized in parasternal and suprasternal views. The normal bifurcation of the pulmonary trunk was absent. Colour Doppler examination aided in clearer delineation and consequent correct identification of the anomalous vessel as the right pulmonary artery.

Aorta↗
PubMed1990

Changing role of non-invasive investigation in the preoperative assessment of congenital heart disease: a nine year experience.

The total surgical experience of a supraregional paediatric cardiology unit over a nine year period (January 1980 to December 1988) was reviewed to assess the effect of the introduction of the full range of ultrasound techniques. A total of 1517 patients underwent cardiac surgery (955 cardiopulmonary bypass, 562 closed procedures). Of these, 485 patients (32%) did not undergo cardiac catheterisation before operation: 217 bypass (23% of all procedures under cardiopulmonary bypass) and 268 closed procedures (48%). The overall ratio of catheterisations to operations for patients undergoing palliative or corrective surgery fell from 0.97 (1980) to 0.38 (1988). The patients were classified as (a) neonates (0-28 days), (b) infants (one to 12 months), and (c) children (one to 14 years). The main impact of non-invasive surgical referral was in neonates (total catheter:operation ratio 0.38; neonates 0.2 for 1988). The surgical population was further divided according to the principal echocardiographic technique available: (a) 1980-4 cross sectional imaging; (b) 1985-6; imaging plus spectral Doppler ultrasound; (c) 1987-8; imaging plus spectral Doppler ultrasound and colour flow mapping. A fall in the catheter:operation ratio for all age groups was most pronounced in the last four years. This reflects increased familiarity and surgical confidence with non-invasive diagnostic assessment. The introduction of each new echocardiographic technique was associated with a significant fall in the total catheter:operation ratio compared with the preceding period. Six incorrect ultrasound diagnoses were made during the entire period; one of these patients died in the early postoperative period. The integration of Doppler ultrasound with cross sectional imaging has made non-invasive assessment an increasingly practical alternative to preoperative cardiac catheterization.

Adolescent↗
PubMed1990

Use of balloon dilatation to treat supravalvar pulmonary stenosis developing after anatomical correction for complete transposition.

Eight balloon dilatations were performed in five patients (aged from 10 to 37 months) in whom supravalvar pulmonary stenosis developed after anatomical correction for complete transposition. The ratio of the maximum diameter of the inflated balloon to the narrowest pulmonary arterial diameter varied from 1.6 to 3.3. In three patients with an initial ratio of less than or equal to 2 dilatation was repeated with a larger balloon. The right ventricular systolic pressure ranged from 0.70 to 1.25 of the simultaneously measured femoral arterial systolic pressure. The major stenosis was in the main pulmonary artery in four patients and at the pulmonary arterial bifurcation in one. After balloon angioplasty in the four patients there was no significant improvement in the ratio of right ventricular to femoral arterial systolic pressure or in the angiographic appearance. There was no change in the pressure ratio after angioplasty in the patient who had a major stenosis of the pulmonary arterial bifurcation and mild main pulmonary artery narrowing. There seemed to be a slight angiographic improvement in the bifurcation stenosis but at restudy two months later the angiographic improvement had disappeared. Balloon angioplasty of supravalvar pulmonary stenosis developing after anatomical correction for complete transposition was not successful in eight procedures. This lack of success may be attributable to a small pulmonary annulus with consequent multiple levels of stenosis and distortion of the main pulmonary artery.

Catheterization↗
PubMed1989

The vectorcardiogram in 4 children undergoing the arterial switch repair.

Four children with complete transposition (concordant atrioventricular and discordant ventriculo-arterial connections), aged 1.2 to 16.4 years, underwent a delayed repair by the arterial switch procedure from March 1985 to October 1986. Three children had undergone previous atrial diversion repairs in early childhood. Two of these children had developed right ventricular dysfunction with tricuspid incompetence as well as having recurrent and symptomatic supraventricular tachyarrhythmias. They underwent banding of the pulmonary trunk 0.7 and 1 year prior to the final repair. The third child had dynamic obstruction of the left ventricular outflow tract and prior banding was not performed. A fourth child had right ventricular dysfunction on initial assessment in early infancy and then had banding of the pulmonary trunk. Two patients survived the arterial switch operation. Vectorcardiograms were performed on these 4 children before arterial switch repair. The left maximal spatial voltage did not correlate with elevated left to right ventricular pressure ratio at cardiac catheterization before arterial switch repair nor did it relate to survival after operation. The horizontal loop was clockwise in all patients preoperatively. The vectorcardiogram in these children was not a useful indicator that the left ventricle was suitably prepared for the arterial switch repair.

Adolescent↗
PubMed1989

Anomalous origin of one pulmonary artery from the ascending aorta: a review of echocardiographic, catheter, and morphological features.

Six patients with anomalous origin of one pulmonary artery from the ascending aorta were reviewed. Four had anomalous origin of the right pulmonary artery and two had anomalous origin of the left pulmonary artery from the ascending aorta. Two of these six patients had tetralogy of Fallot. Two patients died in the first month of life. No changes in the pulmonary vasculature were seen at necropsy. Corrective surgery was attempted in two patients with associated tetralogy of Fallot when they were two years old but both died. At necropsy there was severe pulmonary vascular disease in the lung supplied by the anomalous pulmonary artery but no pulmonary vascular hypertensive changes in the lung supplied by the pulmonary artery from the right ventricle. Two recent patients underwent successful anastomosis of the anomalous pulmonary artery to the main pulmonary artery at three months and one month and three weeks of age respectively. Intraoperative lung biopsy in the latter patient showed early changes in both lungs. Both echocardiography and cardiac catheterisation were used in the diagnoses. Systemic or suprasystemic pressures were found in the pulmonary artery arising from the right ventricle as well as the anomalous pulmonary artery in the three patients without tetralogy of Fallot. Anomalous origin of a pulmonary artery from the ascending aorta is a distinct entity and differs from other aorto-pulmonary arterial connections. Early surgical intervention is recommended in all patients (including those patients with associated tetralogy of Fallot) because of the risk of rapid development of irreversible pulmonary vascular disease.

Adult↗
PubMed1988

The vectorcardiogram in infants undergoing arterial switch repair.

Twenty-five patients with transposition of the great arteries underwent primary arterial switch repair between July 1985 to October 1986. Twenty infants had intact ventricular septum or small ventricular septal defect while 5 infants also had moderate or large ventricular septal defects. Median age of switch repair was 2.9 weeks in those with small ventricular septal defect or intact septum and 7.6 weeks in those with significant defects. Vectorcardiograms were performed weekly preoperatively and then up to 4 to 6 months postoperatively. Cardiac catheterisation was performed preoperatively. Correlation between a left-to-right ventricular pressure ratio of more or less than 0.7 was made with a vectorcardiogram taken near cardiac catheterization. Preoperative vectorcardiograms in patients with essentially intact ventricular septum showed normal maximal spatial voltages in 60 and 65% (left and right) although 70% had clockwise horizontal loops. There was poor correlation between maximal spatial voltages and loops of the vectorcardiogram with the left-to-right ventricular pressure ratio at catheterization. Three of 5 patients with large ventricular septal defects had decreased left maximal spatial voltages or clockwise loops preoperatively. This suggests low left ventricular pressure ratio but at catheterization all had elevated pressure ratios. Despite decreased left maximal spatial voltages or clockwise horizontal loops in many patients in both groups, all survived the arterial switch procedure. Postoperatively, the vectorcardiogram normalized in those with essentially intact septum within a mean of 4 weeks but took longer in the others. The vectorcardiogram is unreliable in assessing suitability for the arterial switch procedure in the first 3 months of life.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1987

Endocardial fibroelastosis in mucopolysaccharidosis type VI.

This case report describes two siblings less than 1 year of age who presented severely ill with a dilated cardiomyopathy. Full blood examination in both cases revealed marked granularity of neutrophils suggestive of mucopolysaccharidosis type VI. There were no physical features of a mucopolysaccharidosis but biochemical evaluation confirmed mucopolysaccharidosis type VI in both children. Autopsy in one patient confirmed endocardial fibroelastosis and electron microscopy of fibroblasts in the myocardium showed distention with membrane-bound vacuoles, consistent with a mucopolysaccharidosis. These siblings developed endocardial fibroelastosis before other clinical manifestations of the mucopolysaccharidosis. Assessment for metabolic causes of a cardiomyopathy is important, as cardiac disease may be the initial manifestation of a metabolic disease.

Endocardial Fibroelastosis↗
PubMed1987

Isolation of the left common carotid or left innominate artery.

Isolation of the left common carotid or left innominate artery from the aortic arch is rare. A six week malformed infant with a right aortic arch had isolation of a left innominate artery and connection to the pulmonary artery by a left ductus arteriosus. A right ductus arteriosus had been ligated. Another infant with a right aortic arch and ostium primum atrial septal defect was shown to have an aberrant left subclavian artery arising from the lower descending aorta. The left common carotid artery filled retrogradely and drained into the pulmonary artery by a left ductus arteriosus. This abnormality has not been reported before.

Abnormalities, Multiple↗
PubMed1985

Congenital diaphragmatic hernia and the management of persistent foetal circulation.

Twenty-two cases of diaphragmatic hernia, presenting from 1978 to 1982, were reviewed. Sixteen patients presented before 24 hours of life, of whom nine survived (56%). Six were late presenters who all did well. Seven babies had ten documented episodes of persistent foetal circulation (PFC) occurring as early as three hours postoperatively, although three babies had episodes in their second week. Hyperventilation, with hand bagging, was successful in treating five out of six episodes of PFC (83%), without complication. Tolazoline caused improvement in two out of four episodes of PFC but was associated with significant complications. We recommend early and sometimes persistent use of hyperventilation by hand bagging as a means of managing PFC in diaphragmatic hernia.

Female↗