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Biomedical subjects

J L Bass

Publications and source records attributed to J L Bass.

At least 37 records · Page 2Linked to original sources

Balloon angioplasty for congenital mitral stenosis.

We attempted balloon angioplasty in 9 children (ages 0.1 to 10 years) with congenital mitral stenosis. All were symptomatic with severe congestive heart failure and failure to thrive. Effective reduction in mitral gradient was initially achieved in 7 patients. For the entire group, mean valve gradient decreased from 14.8 +/- 5.0 to 8.1 +/- 6.7 mm (p = 0.0007) and mean valve area increased from 1.1 +/- 0.5 to 1.8 +/- 0.9 cm2/m2 (p = 0.003). More than mild mitral regurgitation developed in 2 patients but none required surgery for mitral regurgitation. Poor gradient relief followed dilation of valves with unbalanced chordal attachments, with restriction to the valve apparatus as in mitral arcade, and where the obstruction was not purely valvar as it is with a supramitral ring. No strokes, infection or deaths were due to the procedure. Based on these data, balloon angioplasty of congenital mitral stenosis should be considered before mitral valve replacement in younger patients and in those in whom mitral valve replacement would be problematic.

Angioplasty, Balloon↗

Balloon angioplasty--branch pulmonary artery stenosis: results from the Valvuloplasty and Angioplasty of Congenital Anomalies Registry.

Balloon angioplasty for branch pulmonary artery stenosis was reported from 27 institutions to the Valvuloplasty and Angioplasty of Congenital Anomalies Registry. One hundred eighty-two procedures were performed in 156 patients ranging in age from 0.2 to 46.2 years (mean 7.7). Short-term angiographic appearance, hemodynamic results and immediate complications were recorded. Vessel dimension at the site of stenosis increased from 4.5 +/- 2.0 (mean +/- standard deviation) to 6.8 +/- 3.0 mm (p less than 0.001) with greater increases in vessel dimension at the site of stenosis if the balloon diameter was greater than 3 X the original dimension of the stenosis. There was no significant benefit related to age or prior surgical intervention. The mean peak systolic pressure gradient was reduced from 49 +/- 25 to 37 +/- 26 mm Hg (p less than 0.001) and pressure proximal to the stenosis decreased from 69 +/- 25 to 63 +/- 24 mm Hg (p less than 0.001). Complications occurred in 21 patients and included vessel rupture and death in 2 patients, vessel perforation or rupture with survival in 3, cardiac arrest and death in 1, paradoxical embolism and death in 1 and low output and death in 1. Balloon angioplasty for branch pulmonary artery stenosis increases vessel dimension at the site of stenosis, reduces systolic pressure gradient and to a minor degree, reduces proximal pressure. Long-term outcome and potential complications are as yet uncertain.

Catheterization↗

Pediatric problems in a suburban shelter for homeless families.

The experience of an affiliation between a hospital-based clinic and a family shelter is presented. The medical implications of family shelter residence include special issues related to the spread of infectious diseases, particularly to the neonate. Preentry medical evaluation revealed that a large proportion of children and their parents had one or more medical problems. Of 67 children screened before entrance, 13% [corrected] had Giardia lamblia detected in the stool. In addition to carriage of enteric pathogens, the range of pediatric problems encountered included a variety of acute and chronic medical conditions, unmet primary care needs, and developmental and school difficulties. Fifty-eight percent of shelter residents were found to be "medically homeless." Formal liaison between a hospital-based clinic and a family shelter was found to be an effective way to promote a healthy environment in the family shelter and to provide needed medical services to shelter families.

Adolescent↗

Prophylactic furosemide in severe respiratory distress syndrome: blinded prospective study.

To further characterize the place for furosemide in the treatment of newborn infants with respiratory distress syndrome requiring mechanical ventilation, we conducted a blinded, prospective study comparing early prophylactic use (1 mg/kg every 12 hours for four doses beginning at 24 hours of age) with prn use of this drug. Prophylactic administration of furosemide produced no beneficial effect on any measure of pulmonary function compared with use of this drug as needed (prn). However, patients receiving the prophylactic furosemide regimen were found to have more rapid postnatal weight loss, higher pulse rate, and greater sympathomimetic drug requirement during the period of diuretic administration. Patients in the prophylactic group did not demonstrate the moderate expansion in plasma volume between 48 and 96 hours of age seen in the control group. These data suggest that the prophylactic regimen produced an undesirable degree of volume depletion. Further studies should be conducted to develop objective criteria for the selection of the subgroup of patients with respiratory distress syndrome who may benefit from furosemide.

Body Weight↗

Effects of dilating the canine pulmonary annulus with two balloons. Doppler ultrasound and postmortem findings.

Simultaneous inflation of two balloons may be necessary for balloon dilation valvuloplasty in patients with a large annulus. We examined the cardiovascular effects of dilating the pulmonary annulus with two balloons in 18 normal dogs using pulsed Doppler ultrasound and gross and microscopic examination. When the ratio of the cross-sectional area (CSA) during dilation to the CSA of the pulmonary annulus was between 1.04 and 1.28, there was valvar regurgitation in only one dog, in which catheter manipulation was complicated by heartworms, and damage was confined to intimal changes. (The dog was killed 24 hours after dilation.) With ratios between 1.67 and 1.76 (equal to the CSA of a single balloon with a diameter 33% greater than the annulus), there was trivial or mild tricuspid or pulmonary regurgitation, and anatomic changes were more prominent but still superficial. Two animals killed after nine days had resolution of valvar regurgitation and healing damage. With CSA ratios greater than 2.00 or with balloon rupture, myocardial damage and laceration of the pulmonary arteries resulted. Simultaneous inflation of two balloons within the right ventricular outflow tract with CSA ratios of up to 1.76 results in minimal cardiovascular trauma.

Animals↗

Evaluation of coronary artery anatomy in patients with tetralogy of Fallot by two-dimensional echocardiography.

A major coronary artery crossing the right ventricular outflow tract in patients with tetralogy of Fallot interferes with a transannular patch, and preoperative detection of this artery is important. We evaluated the ability of two-dimensional echocardiography to define noninvasively the coronary artery anatomy in 37 consecutive patients (age range, 1 day to 18 years; mean age, 40.9 months). The origin and distribution of the right anterior descending and circumflex coronary arteries, as well as any anteriorly coursing vessel, were examined from parasternal views. Complete studies were obtained in 29 (78%) of the 37 patients. Coronary artery anatomy was determined to be normal by echocardiography in 20 (69%) of the 29 patients. An anterior vessel across the right ventricular outflow tract was detected in the remaining nine patients. Six patients had an anterior descending artery from the left main coronary artery (paired anterior descending arteries in three patients, a right anterior descending artery from the left main coronary artery in two patients, and a right coronary-to-pulmonary artery fistula in one patient). Three patients had no anterior descending artery from the left main coronary artery (anterior descending artery from the right main coronary artery in two patients, and anterior descending and circumflex arteries from the right main coronary artery in one patient). Angiography, surgery, or autopsy confirmed the diagnoses in all but the final patient in whom the anterior descending artery arose from the right main coronary artery as observed at surgery, but the circumflex artery was not seen. Accurate evaluation of coronary artery anatomy is possible by echocardiography in the majority of patients with tetralogy of Fallot. Noninvasive identification of a major coronary artery coursing anteriorly can influence the timing of cardiac catheterization and surgery and the need for angiography.

Adolescent↗

Echocardiographic versus cardiac catheterization diagnosis of infants with congenital heart disease requiring cardiac surgery.

The success of noninvasive preoperative evaluation of infants with congenital heart disease using cardiac ultrasound depends not only on diagnostic accuracy, but also on risk of morbidity and mortality as compared with infants who undergo cardiac catheterization. Fifty-six infants (age 10 weeks or younger) with coarctation of the aorta (n = 16), coarctation with ventricular septal defect (n = 12), valvar aortic stenosis (n = 10) or total anomalous pulmonary venous connection (n = 18) were examined. Thirty-one underwent noninvasive preoperative assessment and 25 underwent evaluation including cardiac catheterization. Age, level and duration of support, pH, renal function, mortality, complications of cardiac catheterization and errors of diagnosis were compared. Significant differences between the 2 groups were more frequent preoperative use of prostaglandin E1 and shorter hospital stay in the noninvasively evaluated coarctation group. Of the infants with coarctation and ventricular septal defect, 1 who had cardiac catheterization required renal transplantation and 1 evaluated noninvasively required surgery at age 3 months for mitral stenosis not discovered on preoperative evaluation. One noninvasively evaluated infant with total anomalous pulmonary venous connection had a stenotic communication between the pulmonary venous confluence and the left atrium not detected by ultrasound. Surgery was successful in the latter 2 infants. Noninvasive preoperative diagnosis of some infants with congenital heart disease can be performed without increasing the risk of operative morbidity and mortality. Eliminating cardiac catheterization reduces hospital costs, decreases total numbers of catheterizations performed and influences the structure of training programs.

Cardiac Catheterization↗

Asymptomatic toxocariasis in children. A prospective study and treatment trial.

Screening of 153 Hispanic children attending a Hospital-based primary care clinic revealed a 16 percent prevalence of Toxocara canis infection. Infections were found in other household occupants for half of these children. Follow-up of 20 children (for periods of up to 7 years) with asymptomatic T. canis infection failed to demonstrate any clinical sequelae. However, longer periods would be necessary to entirely discount the possibility of latent ocular disease. Treatment with thiabendazole did not appear to alter the course of the infection in a controlled 1-year evaluation as measured by eosinophil counts and specific T. canis antibody titers.

Adult↗

Percutaneous balloon dilation angioplasty of pulmonary artery branch stenosis.

Congenital or acquired branch pulmonary artery stenosis can produce significant right ventricular hypertension and complicate the management of patients with tetralogy of Fallot. Repair is difficult using conventional surgical techniques. Balloon dilation angioplasty may be beneficial to some patients with these lesions. The technique currently used at the University of Minnesota is described. Results indicate that half of attempted dilations are successful with increased diameter of the narrowed areas, decreased pressure gradient, and improved pulmonary blood flow to the involved lung. Failure may be caused by technical limitations (28%) or lesions that are not dilatable with current equipment (22%). Undilatable lesions are more common in children over 2 years of age, in isolated pulmonary artery stenosis, and with associated surgical shunts. Complications are uncommon.

Age Factors↗

Flow in the aorta and patent ductus arteriosus in infants with aortic atresia or aortic stenosis: a pulsed Doppler ultrasound study.

We used pulsed Doppler ultrasound to determine the flow dynamics of the aorta and patent ductus arteriosus (PDA) in 21 infants (ages 1 to 16 days) with PDA and aortic atresia (n = 15) or aortic stenosis (n = 6). The flow within the PDA was recorded in 19, and was right-to-left during systole in all. There was a diastolic left-to-right PDA shunt in 11 patients with aortic atresia and in three with aortic stenosis, and the shunt was associated with large (3 to 11 mm in diameter) interatrial communications. In two patients with aortic atresia and three with aortic stenosis, however, the diastolic PDA shunt was from right to left, and the interatrial communications were small (0 to 2 mm in diameter). The right-to-left diastolic PDA shunting may be best explained by the relative pulmonary (high with left-sided inflow obstruction and a small interatrial communication) and systemic resistances. All patients with aortic atresia and three with aortic stenosis had retrograde systolic flow in the transverse aortic arch, probably resulting from inadequate left ventricular output. Antegrade diastolic flow in the transverse aortic arch toward the PDA was observed in all infants with aortic atresia and a left-to-right PDA shunt. Ascending aortic flow was recorded in 11 patients with aortic atresia, and was retrograde during diastole in each, the result of coronary perfusion. Application of pulsed Doppler ultrasound can lead to a better understanding of the hemodynamics and physiology of patients with congenital cardiovascular disease.

Aorta↗

Echocardiographic incidence of cardiac rhabdomyoma in tuberous sclerosis.

Cardiac rhabdomyoma occurs frequently in patients with tuberous sclerosis (TS). Although there have been case reports of detection of cardiac rhabdomyoma by 2-dimensional echocardiography, no study has examined the frequency of cardiac rhabdomyoma detected by cardiac ultrasound in patients with TS. Echocardiography was performed in 16 consecutive patients with TS. Physical examination revealed normal cardiac findings in each. Discrete areas of increased acoustic density were found in 8 of the 16 patients (50%). The maximum diameters ranged from 3 to 20 mm. Multiple areas were found in 3 of 8. The left ventricle was involved in 5 of the 8. Six masses were intracavitary and 8 were intramyocardial. No atrial masses were seen. Left ventricular size and function were normal. Although other tumors cannot be excluded, the diagnosis of cardiac rhabdomyoma is almost certain in these young patients with TS. The male predominance and the high incidence of intracavitary and left ventricular masses are similar to those in reported autopsy series, also supporting the diagnosis of cardiac rhabdomyoma. The prognosis and potential for growth of these masses are not known, but can be determined by longitudinal follow-up. Cardiac ultrasound should be considered for all patients with TS regardless of physical findings.

Adolescent↗