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Biomedical subjects

R A Hurwitz

Publications and source records attributed to R A Hurwitz.

At least 37 records · Page 2Linked to original sources
PubMed1986

Role of radionuclide shunt studies in management of infants and children.

The utility of radionuclide-shunt quantitation in children was assessed by examination of the outcome of 128 patients who underwent shunt study over a two-year period. The possibility of cardiac catheterization was eliminated in 87. Fifty of these had undergone previous cardiac catheterizations, which suggested the necessity for further invasive study or surgery; after radionuclide evaluation, 28 were shown to have had enough spontaneous closure of the defect to cancel planned surgery, 12 were scheduled for surgery without repeat catheterization, and ten had nuclear rather than catheterization estimates of residual shunting following surgical repair of septal defects. Thus, radionuclide shunt study provides a relatively noninvasive technique to quantitate left-to-right shunts, supplementing or supplanting cardiac catheterization in the management of infants and children with such lesions.

Adolescent↗
PubMed1985

Ventricular function in transposition of the great arteries: evaluation by radionuclide angiocardiography.

Right ventricular ejection fraction and tricuspid regurgitation were estimated by radionuclide angiocardiography to quantitate systemic ventricular function in "simple" transposition of the great arteries. Mean right ventricular ejection fraction was 0.52 +/- 0.07 for 18 pre Mustard operation infants, 0.54 +/- 0.07 for 23 patients operated upon less than a 1 year before, and 0.57 +/- 0.08 for 14 patients operated upon more than 3 years earlier. Eight patients were evaluated before and following the Mustard operation; ejection fraction rose in three, fell in three, and remained constant in two. Mean right ventricular ejection fraction was not different between groups nor when compared to our "normal." The left ventricle:right ventricle stroke volume ratio of the postoperative patients was compatible with tricuspid regurgitation in four patients. This radionuclide study suggests that following surgery for transposition of the great arteries: mean right ventricular systolic ejection fraction remains at levels consistent with values usually found for the "normal" right ventricle; group right ventricular function does not deteriorate in the years following surgery; and tricuspid regurgitation may be detected in the early postoperative years.

Aging↗
PubMed1985

Indomethacin therapy on the first day of life in infants with very low birth weight.

To investigate the optimal timing for treatment of small premature infants, we performed a double-blind, controlled trial of indomethacin therapy on the first day of life in 104 infants weighing between 700 and 1300 gm. Infants were given indomethacin or placebo at a mean age of 15 hours. Eleven of the 56 infants given placebo developed large left-to-right shunts through a patent ductus arteriosus. In contrast, only two of the 51 infants given indomethacin developed large shunts (P less than 0.025). There were no significant differences in incidence of surgical ligation, duration of oxygen therapy, duration of endotracheal intubation, days required to regain birth weight, or incidence of complications. However, the power of the tests of significance was low because of the small number of patients. Thus, although the incidence of large left-to-right ductus shunts was decreased in the indomethacin group, morbidity was not otherwise altered for the entire group of patients, possibly because of the relatively low incidence (21%) of large shunts in the placebo group. We conclude that although treatment with indomethacin on the first day of life appears to be safe, there is little advantage to its use in centers where the incidence of large shunts through a patent ductus arteriosus is relatively low.

Double-Blind Method↗
PubMed1984

Right ventricular and left ventricular ejection fraction in pediatric patients with normal hearts: first-pass radionuclide angiocardiography.

First-pass radionuclide angiocardiography was used to estimate right ventricular (RV) ejection fraction (EF) and left ventricular (LV) EF in infants, children, and teenagers with normal hearts. The right ventricle was analyzed in 74 patients and the left ventricle in 72 patients. Mean RVEF for the group was 0.53 +/- 0.06 (range 0.43 to 0.73); mean LVEF for the group was 0.68 +/- 0.09 (range 0.49 to 0.86). Lower values tended to be present in younger patients. However, there was no statistical difference in EFs between age groups and no linear correlation between magnitude of EF and age or EF and heart rate for either ventricle. Data obtained demonstrated that RVEF and LVEF in children with normal hearts are similar to those in adults with normal cardiovascular systems. A RVEF of 0.41 to 0.47 or a LVEF of 0.50 to 0.59 would suggest borderline systolic function; a RVEF less than 0.41 (mean -2 SD) or LVEF less than 0.50 (mean -2 SD) would be considered abnormal when this technique of first-pass radionuclide angiocardiography is used.

Adolescent↗
PubMed1984

Apicoaortic valved conduits for complex left ventricular outflow obstruction: technical considerations and current status.

The surgical considerations, clinical follow-up, and hemodynamic data for 23 patients (age range, 4 months to 80 years) who underwent insertion of a porcinevalved apicoaortic conduit between December, 1976, and June, 1983, are reviewed. All patients had complex forms of left ventricular outflow obstruction. All were symptomatic, and 18 had had 23 prior attempts at surgical relief of the obstruction. There was a total of 6 deaths (26%); 2 were in small children with other complex cardiac malformations, and 2 others in patients who required emergency operation for acute cardiac decompensation. Sixteen patients have had cardiac catheterization 1 to 1.5 years postoperatively, and a reduction in the resting left ventricular-aortic gradient from 91 +/- 30 to 13 +/- 8 mm Hg was demonstrated (p less than 0.001). None of the patients is taking anticoagulants, and no thromboembolic events have occurred. Four of the 17 survivors have undergone a subsequent operation 1.5 to 4.0 years postoperatively with conduit removal, aortoventriculoplasty, and conduit valve replacement in 1, 1, and 2 patients, respectively. These data demonstrate that the apicoaortic conduit is effective in relieving complex left ventricular outflow obstruction and improving left ventricular performance with acceptable long-term results. Increasing the durability of the conduit valve will greatly improve the late results with this technique.

Adolescent↗
PubMed1983

Quantitation of aortic and mitral regurgitation in the pediatric population: evaluation by radionuclide angiocardiography.

The ability to quantitate aortic (AR) or mitral regurgitation (MR), or both, by radionuclide angiocardiography was evaluated in children and young adults at rest and during isometric exercise. Regurgitation was estimated by determining the ratio of left ventricular stroke volume to right ventricular stroke volume obtained during equilibrium ventriculography. The radionuclide measurement was compared with results of cineangiography, with good correlation between both studies in 47 of 48 patients. Radionuclide stroke volume ratio was used to classify severity: the group with equivocal regurgitation differed from the group with mild regurgitation (p less than 0.02); patients with mild regurgitation differed from those with moderate regurgitation (p less than 0.001); and those with moderate regurgitation differed from those with severe regurgitation (p less than 0.01). The stroke volume ratio was responsive to isometric exercise, remaining constant or increasing in 16 of 18 patients. After surgery to correct regurgitation, the stroke volume ratio significantly decreased from preoperative measurements in all 7 patients evaluated. Results from the present study demonstrate that a stroke volume ratio greater than 2.0 is compatible with moderately severe regurgitation and that a ratio greater than 3.0 suggests the presence of severe regurgitation. Thus, radionuclide angiocardiography should be useful for noninvasive quantitation of AR or MR, or both, helping define the course of young patients with left-side valvular regurgitation.

Adolescent↗
PubMed1983

Two-dimensional echocardiographic differentiation of anomalous left coronary artery from congestive cardiomyopathy.

Infants having anomalous origin of the left coronary artery (ALCA) from the pulmonary artery may at times be difficult to distinguish clinically from those having a congestive cardiomyopathy (CCM). Five children having ALCA and 15 having CCM were studied by two-dimensional echocardiography (2DE) and angiography. The left coronary artery (LCA) was demonstrated by 2DE to arise normally in all children having CCM. The LCA aortic ostium was not recorded in any child with ALCA; however, the LCA was recorded in three patients. The 2DE recorded the LCA originating from the pulmonary artery in two of these infants. A prominent right coronary artery was seen in all patients with ALCA. Thus 2DE is helpful in distinguishing patients having ALCA from those with CCM.

Cardiac Catheterization↗
PubMed1983

Right ventricular infarction with cardiac rupture in an infant with pulmonary valve atresia with intact ventricular septum.

This report describes an 8 day old infant with pulmonary valve atresia, hypoplastic and hypertensive right ventricle and myocardial sinusoid-left anterior descending coronary artery connections. A large right ventricular sinusoid complex developed that was associated with transmural right ventricular necrosis and cardiac rupture. This is the first report to document transmural myocardial infarction and rupture in pulmonary valve atresia with intact septum, and this condition should be added to the causes of myocardial infarction in infancy. A reduced number of caliber of sinusoid-coronary artery channels may be responsible for right ventricular damage in this condition.

Coronary Vessel Anomalies↗
PubMed1982

Supraventricular tachycardia with edema, ascites, and hydrops in fetal sheep.

Continuous supraventricular tachycardia was induced in 13 fetal sheep for 72 to 216 hours. The PaO2 decreased from 18.1 +/- 1.2 (SEM) to 15.4 +/- 0.9 mm Hg and the PaCO2 increased from 41.5 +/- 1.2 (SEM) to 46.0 +/- 1.0 (SEM) mm Hg with pacing. The hematocrit, total protein, albumin, serum [Na+] and [K+], and osmolality remained unchanged throughout the study. All study fetuses showed signs of ascites (mean = 88 +/- 67.5 [SD] ml), and one was grossly hydropic. Six fetuses, all of which had greater than or equal to 50 ml of ascites, died as the results of pacing. Gross pathologic findings in 13 fetuses included: cardiomegaly in seven, cyanotic myocardium in two, hepatomegaly in seven, pulmonary congestion in two, generalized edema in three, and massive edema (hydrops) in one. None of these conditions was found in the 14 control animals. There was no correlation of the severity of effects upon the fetus and the induced heart rate, the duration of tachycardia, or the site of implantation of the pacemaker. The conclusion was that organomegaly, generalized edema, and hydrops fetalis were the direct result of supraventricular tachycardia in utero; the exact mechanism of production and the reasons for the variable manifestations of tachycardia remain unclear.

Animals↗
PubMed1982

Heparinization for prevention of thrombosis following pediatric percutaneous arterial catheterization.

One thousand three hundred and sixteen consecutively catheterized infants and children were evaluated prospectively for femoral artery thrombosis following percutaneous cardiac catheterization. One hundred units/kg heparin bolus was given to 649 patients after arterial puncture (group A). A supplementary 50 units/kg of heparin bolus was given to 381 patients 75 minutes later, followed by a continuous heparin infusion if pulses were decreased (group B). Two hundred forty-one patients were managed similarly except the first supplementary bolus was given 45 minutes after initial heparinization, if necessary, and the second bolus and continuous infusion were begun 45 minutes later, if necessary (group C). Arterial thrombosis was diagnosed if pulses were not equal to those of the unused extremity 6 hours following catheterization. The overall incidence of arterial thrombosis was 0.8%. No statistically significant (p less than .05) differences occurred related to the heparinization method used. However, absence of thrombosis in the last 241 consecutive patients (group C) and in the last 480 patients of groups B and C weighing more than 10 kg approaches significance (p less than .1). Incidence of thrombosis was less than in previous studies (p less than .0005 to .05). This study indicates that a very low incidence of arterial thrombosis can be achieved with systemic heparinization.

Adolescent↗
PubMed1982

Radionuclide angiocardiography in evaluation of patients after repair of transposition of the great arteries.

The ability of first pass radionuclide angiocardiography to detect and quantitate residual intracardiac shunts and systemic venous obstruction after repair of transposition of the great arteries was evaluated in 29 children. Information from radionuclide scans was compared with data obtained during cardiac catheterization. Three children had a residual right to left shunt detected with both methods. There was good agreement between radionuclide and catheterization quantitation of left to right shunt in the nine patients with a residual defect, five of whom had significant shunting. Nineteen patients with signs suggesting superior vena caval obstruction were evaluated with both radionuclide and catheterization methods. In eight, complete obstruction was detected with both techniques; in one additional patient, partial obstruction was found on catheterization only. One of six patients evaluated for possible inferior vena caval obstruction was identified with both techniques. In the group as a whole, information obtained with radionuclide angiography correlated well with cardiac catheterization data in evaluation of residual shunts and obstruction to systemic venous return.

Adolescent↗
PubMed1982

Splenic scintigraphy using Tc-99m-labeled heat-denatured red blood cells in pediatric patients: concise communication.

Ten children underwent splenic imaging with heat-denatured red blood cells labeled with technetium-99m (Tc-99m DRBC). The presenting problems included the heterotaxia syndrome, recurrent idiopathic thrombocytopenic purpura following splenectomy, mass in the left posterior hemithorax, and blunt abdominal trauma. In nine patients, the presence or absence of splenic tissue was established. A splenic hematoma was identified in the tenth patient. All patients were initially scanned with Tc-99m sulfur colloid (Tc-99m SC), and were selected for Tc-99m DRBC scintigraphy only after the results of the SC scans failed to establish the clinical problem beyond doubt. The availability of kits containing stannous ions, essential for efficient and stable labeling of red blood cells with Tc-99m and requiring only a small volume of blood, make splenic scintigraphy in children a relatively simple and definitive diagnostic procedure, when identification of splenic tissue is of clinical importance.

Abdominal Injuries↗
PubMed1980

Tetralogy of Fallot with abnormal coronary artery: 1967 to 1977.

From 1967 to 1977, 25 of 250 children undergoing complete repair of tetralogy of Fallot had an abnormal coronary artery identified at operation. Eight (Group 1) had classical anomalous coronary artery, and 17 (Group 2) had a large aberrant artery in addition to a smaller, normally positioned artery. All 25 patients required surgical procedures different from those routinely employed in tetralogy of Fallot repair. These included a "tailored" ventriculotomy, double incision, and accessory right ventricle-to-pulmonary artery conduit. After identification of a parallel (smaller) coronary artery, the anomalous coronary artery was ligated in three. Two patients (Group 2) died following the operation, both with "tailored" incisions. These were two of the four with high residual right ventricular pressure. Survivors have done well clinically for at least 1 year. Postoperative catheterization has shown high residual right ventricular pressure in two patients and an insignificant residual ventricular septal defect in four patients none has required reoperation.

Cineangiography↗
PubMed1979

Right ventricular outflow tract assessment by cross-sectional echocardiography in tetralogy of Fallot.

Cross-sectional echocardiographic (CSE) studies were obtained in 29 children with tetralogy of Fallot. In this study we evaluated the capability of CSE to record the right ventricular outflow tract (RVOT) and compared the severity of infundibular obstruction determined by CSE with cineangiographic (cine) determinations. In addition, we examined capabilities of CSE and M-mode echocardiography (M-mode) to record the diagnostic features of tetralogy of Fallot, including RVOT obstruction, aortic overriding, ventricular septal defect, and presence of the pulmonary valve. An excellent correlation (r = 0.925) was found for the combined pre- and post-repair patients studied by CSE vs cine, while the correlation (r = 0.805) for M-mode was not as good. The difference was even more striking for the unrepaired patients, in which the correlation (r = 0.746) for CSE was much better than for M-mode (r = 0.374). In the unrepaired patients, CSE allowed easier detection of the ventricular septal defect than M-mode (95% for CSE vs 76% for M-mode). The pulmonary valve was recorded in 90% by CSE, but in only 26% by M-mode. Aortic overriding was recorded in all unrepaired patients both by CSE and M-mode. These data indicate that CSE is better than M-mode for recording the RVOT dimensions, ventricular septal defect, and the pulmonary valve in unrepaired patients with tetralogy of Fallot.

Aorta↗
PubMed1979

Fetal and neonatal ventricular arrhythmia.

Ventricular arrhythmia in the perinatal period is observed with greater frequency than reported in the literature. Four cases from the authors' experience and an analysis of the literature are presented. Of the total of 45 cases, nine were detected in utero, three persisted beyond the neonatal period, and two resulted in death with associated disorders. Twenty-four percent of the entire group had serious medical disorders associated with arrhythmia; however, 43% of the group with ventricular tachycardia had major associated disease.

Arrhythmias, Cardiac↗