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Biomedical subjects

R M Freedom

Publications and source records attributed to R M Freedom.

At least 199 records · Page 11Linked to original sources
PubMed1989

Surgical experience with left ventricular outflow tract obstruction in patients with complete transposition of the great arteries and essentially intact ventricular septum undergoing the Mustard operation.

During a 24-year period (1963-1987), 46 infants and children with complete transposition of the great arteries (CTGA) and an essentially intact ventricular septum (IVS) have undergone surgical relief of left ventricular outflow tract obstruction (LVOTO) concurrently with the Mustard operation (MO). The obstruction was valvar in 2 patients, subvalvar in 43 and combined valvar and subvalvar in 1; the ventricular septum was intact in 42, and 4 patients had a small VSD at the time of repair. Neonatal and pre-Mustard cardiac catheterization (CC) data were analyzed to obtain LV to right ventricular peak systolic pressure ratio (LV/RVPSP) and LVOT peak systolic gradient (PSG). The mean neonatal LV/RVPSP (n = 31) was 0.79 +/- 0.04; pre-Mustard LV/RVPSP (n = 44) was 0.75 +/- 0.05; pre-Mustard LVOT PSG (n = 34) was 46.5 +/- 3.5 mmHg. Neonatal (n = 29) and pre-Mustard (n = 30) cardiac angiograms were retrospectively reviewed to analyse morphologic substrates of LVOTO. In the neonatal period, LVOTO was present in 7 patients (anatomic, n = 4; dynamic, n = 2; combined, n = 1). Immediately prior to the MO, LVOTO was present in 29 (anatomic, n = 20; dynamic n = 2; combined, n = 7). Techniques to correct LVOTO at the initial MO included pulmonary valvotomy (n = 3), ventriculomyectomy (n = 41), resection of an windsock aneurysm (n = 1), LV to pulmonary artery valved conduit (VC) (n = 1). Two patients underwent VC early postoperatively (PO) for severe residual LVOTO (both died).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiocardiography↗
PubMed1989

Abnormal cardiac signs after Fontan type of operation: indicators of residua and sequelae.

Among 74 survivors of the Fontan type of operation abnormal cardiac signs were detected in 46 (62%) at postoperative examination. The findings were analysed in relation to the state of the cardiovascular system of these patients. Cyanosis was present in 10 (13.5%) patients. The causes of cyanosis included residual interatrial shunt (six patients), acquired pulmonary arteriovenous fistulas (three patients) and acquired systemic-to-pulmonary vein communication (one patient). Signs of chronic fluid retention were detected in six (8%) patients. In four of them the fluid retention was related to conduit obstruction and in the remaining two it was secondary to severe subaortic stenosis in one and atrioventricular valvar regurgitation in the other. Organic heart murmurs were heard in 29 (39%) patients. The aetiologies of these murmurs were multiple. They included aortic valve regurgitation (eight patients), subaortic stenosis (seven patients), atrioventricular valvar regurgitation (five patients), pulmonary valve regurgitation (five patients), residual Blalock-Taussig shunt (two patients), residual ventricular septal defect (two patients), residual communication in the main pulmonary artery which had been ligated but not divided (one patient), and left ventricular to right atrial shunting (one patient). Cardiac rhythm disturbances of varying aetiology were noted in 23 (31.1%) patients. Sixteen (21%) had supraventricular arrhythmias and seven (9.5%) had conduction abnormalities. The present review suggests that among survivors of the Fontan type of operation abnormal cardiac signs are indicators of residua or sequelae or both of the native cardiovascular anomalies or surgical procedures.

Adolescent↗
PubMed1989

Determination of left ventricular volumes by Simpson's rule in infants and children with congenital heart disease.

Regression equations were developed from left ventricular casts of known volumes to calculate left ventricular volumes from biplane cineangiography obtained in non-standard views. Volumes were calculated by Simpson's rule from casts of postmortem specimens from patients with congenital heart disease. The casts were divided into two groups: those that came from patients with abnormal right ventricular haemodynamic function (group 1, n = 11) and those that came from patients in which it was normal (group 2, n = 9). Biplane cinegrams were taken in conventional (anteroposterior/lateral, right anterior oblique/left anterior oblique) and non-conventional (long axis oblique, hepatoclavicular, and sitting up) projections. The true volume of each cast was determined from its weight and specific gravity. Correlations between measured and true volumes (r = 0.96 to 0.99) were excellent in all projections, although each projection overestimated the true volumes (slope = 0.72 to 0.94). The regression equations obtained from conventional views were significantly different from those from the non-conventional views; however, the regression slopes in group 1 were not different from those in group 2 in any view. Regression equations obtained by Simpson's rule do not seem to be affected by the haemodynamic state of the right ventricle. Different regression equations are required to measure left ventricular volumes from non-conventional angiograms.

Anthropometry↗
PubMed1989

Distinguishing between anomalous origin of the left coronary artery from the pulmonary trunk and dilated cardiomyopathy: role of echocardiographic measurement of the right coronary artery diameter.

Patients with anomalous origin of the left coronary artery from the pulmonary trunk usually have a large right coronary artery. This study examines the diagnostic value of measuring the diameter of the right coronary artery by echocardiography in distinguishing between this lesion and other causes of dilated cardiomyopathy. The diameter of the right coronary artery and the right coronary artery/aorta ratio were measured in the parasternal short axis view in 40 controls, 11 patients with dilated cardiomyopathy, and 10 with anomalous origin of the left coronary artery from the pulmonary trunk. In the controls, the diameter of the right coronary artery increased with age, but the right coronary artery/aorta ratio remained constant. In the control group the 95% upper limits of prediction for right coronary artery diameter were 1.6 mm for one month of age, 1.8 mm for three months, 2.0 mm for one year, 2.2 mm for two years, 2.4 mm for three years, 2.6 mm for four years, 2.7 mm for six years, 3.0 mm for eight years, and 3.2 mm for 10 years; and for right coronary/aorta ratios the limits were 0.17 for one month to one year, 0.18 for one to six years, 0.19 for six to 10 years, and 0.20 for more than 10 years. All patients with dilated cardiomyopathy had normal right coronary artery diameters and right coronary artery/aorta ratios (0.10-0.13). Those patients with anomalous origin of the left coronary artery from the pulmonary trunk had larger than normal right coronary artery diameter and a significant increase in the right coronary artery/aorta ratio (0.21-0.29). The presence of an anomalous left coronary artery was likely if the diameter of the right coronary artery or the right coronary artery/aorta ratio was larger than the normal 95% limits of prediction.

Cardiomyopathy, Dilated↗
PubMed1989

Balloon dilatation of congenital aortic valve stenosis in infants and children: short term and intermediate results.

Percutaneous balloon dilatation of the aortic valve was attempted in 25 consecutive patients with stenosis. The aortic valve diameters were normal for age. The balloon catheters were placed retrogradely, and their diameters were within 1-2 mm of the valve diameter and 3 (13 patients) or 6 cm (recent 12 patients) long. After dilatation the pressure gradients across the aortic valve were reduced significantly and the valve areas, measured in 10 patients, increased. Aortic regurgitation was detected in six patients before (grade I) the procedure and in 15 patients (6 grade I, 6 grade II, 3 grade III) after the procedure. In one patient the aortic valve could not be crossed and in three there was no reduction in the pressure drop. Nine patients have a sustained reduction in Doppler assessed gradients. There were vascular complications in 12 and these required surgical intervention in three patients. Balloon dilatation seems to be an effective short term palliative procedure in patients with congenital stenosis of the aortic valve.

Adolescent↗
PubMed1989

Two-dimensional echocardiographic and color flow Doppler evaluation of ductal occlusion with the Rashkind prosthesis.

To evaluate the results of ductal occlusion with the Rashkind prosthesis, 78 children (group 1, 19 boys and 59 girls; mean age at occlusion, 4.5 +/- 4.0 years) with isolated patent ductus arteriosus (n = 73) or in association with other lesions (n = 5) were evaluated by pulsed and color flow Doppler 9 +/- 7 months (range, 2-26 months) after occlusion. Thirty children who had undergone patent ductus arteriosus ligation (group 2, 9 boys and 21 girls; mean age at study, 5.7 +/- 4.9 years; mean follow-up after ligation, 44 +/- 58 months) were evaluated in the same way. The prevalence of residual ductal shunting and the main pulmonary arterial flow patterns were recorded. Residual ductal shunting in group 1 was 38% on day 1, decreasing slowly to 31% at 3 months, 27% at 6 months, and 19.7% at 1 year or more due to further spontaneous shunt resolution. The residual shunting rate in group 2 (6%) was significantly lower than that at 1 year or more in group 1 (p less than 0.001). Successful reocclusion in 5 of 6 in a subset of patients in group 1 followed for 1 year or less reduced further the prevalence of residual shunting. Residual shunting after patent ductus arteriosus occlusion is more common than after ligation, but continues to decrease during follow-up.

Child, Preschool↗
PubMed1989

Reocclusion for persistent shunting after catheter placement of the Rashkind patent ductus arteriosus occluder.

Between February 1986 and January 1989, 105 percutaneous catheter occlusions of patent ductus arteriosus were undertaken, with six patients having residual left-to-right shunting confirmed by colour-flow Doppler nine months to years after initial occlusion. Five of six had successful reocclusion by placement of a second 12 mm Rashkind device. All successful reocclusions had continuous murmurs. Colour-flow Doppler characterized residual shunting as a discrete jet coursing superior to the device in five and through the pods in one. No left pulmonary artery obstruction was detected following placement of the second device. All patients were discharged the day of or the day following reocclusion.

Angioplasty, Balloon↗
PubMed1988

Catheter occlusion of the persistently patent ductus arteriosus.

Catheter occlusion of a persistently patent ductus arteriosus was attempted in 40 patients (11 men and 29 women, mean age 7.2 +/- 8.3 years, range 244 days to 40 years), using a transvenously placed Rashkind umbrella occluder (USCI). Thirty-one 12-mm and six 17-mm diameter devices were successfully placed in the ductus (internal diameter average 3.9 mm, range 2 to 9 mm). One procedure was abandoned when fluoroscopy failed to visualize the device. There were 2 immediate embolizations subjected to surgical recovery. A residual shunt was present on the immediate postocclusion ventriculogram in 12 of 37 procedures (32%). Twenty-eight patients (75%) have had at least a follow-up at 3 months with Doppler study and 6 (21%) continued to have shunting into the pulmonary artery. Three of 4 patients have undergone successful placement of a second device and 1 patient's shunting spontaneously resolved at 1 year postimplant, leaving only 2 patients (7%) with persistent shunts. There has been 1 episode of probable prosthetic endarteritis and 1 patient has developed mild narrowing of the left pulmonary artery related to device placement. Catheter occlusion of the patent ductus arteriosus using the Rashkind umbrella appears to be a safe and effective method of non-surgical management.

Adult↗
PubMed1988

Natural history and prognostic risk factors in endocardial fibroelastosis.

A retrospective study was made of 52 patients (16 men, 36 women) with endocardial fibroelastosis diagnosed by strict clinical criteria and confirmed histologically in 18 (35%). Clinical and hemodynamic manifestations at presentation were reviewed from the clinical record. The follow-up period averaged 47 months (range 1 day to 228 months). Actuarial survival rates were 93% at 6 months, 83% at 1 year and 77% at 4 years. Clinical and hemodynamic manifestation included onset at less than 1 year of age (89%), respiratory distress (71%), cardiomegaly on chest roentgenogram (99%), left ventricular hypertrophy with ST-T-wave changes on the electrocardiogram (97%) and reduced contractility with dilatation of the left ventricle (100%). Prognostic risk factors were evaluated comparing 13 patients who died (group 1) with 16 patients who survived greater than 4 years (group 2). Only cardiac index (2.8 +/- 0.8 vs 3.5 +/- 0.5 liter/min/m2) and ejection fraction (18 +/- 12 vs 33 +/- 21%) measured at catheterization were significantly reduced in group 1 compared with group 2 (p less than 0.005 and p less than 0.01, respectively). Careful observation and appropriate management are recommended in all patients, although low ejection fraction and cardiac output at presentation are predictive of poor outcome and support other therapeutic alternatives.

Child↗
PubMed1988

An echocardiographic study of the association of ventricular septal defect and right ventricular muscle bundles with a fixed subaortic abnormality.

Since 1983, 36 patients with the combination of right ventricular muscle bundles and a perimembranous ventricular septal defect have been studied in our institution to address the incidence of on associated subaortic abnormality. Of that total 32 (88%) had echocardiographic evidence of such an abnormality (29 had a typical subarotic ridge protruding from the crest of the interventricular septum and the remaining 3 had an echodense area in the same location). Surgical confirmation of the presence or absence of a subaortic abnormality was available in 26. There was correlation between the surgical and echocardiographic findings in all patients. A resting Doppler gradient of greater than or equal to 10 mm Hg was present in only 10. During the study period, 6 patients had Doppler evidence of progression of their gradient. The incidence of subaortic abnormalities in right ventricular muscle bundles and ventricular septal defects appears to be far greater than previously suspected. The exact significance of this finding in the absence of a pressure gradient is still unclear.

Child, Preschool↗
PubMed1988

Correlation of left ventricular angiographic casts and biplane left ventricular volumetry in infants and children.

To calculate left ventricular (LV) volumes from biplane cineangiography obtained in nonstandard views, regression equations were developed from LV casts of known volume. Volumes were calculated by the area-length method from casts ranging from 1.4 to 48.9 ml obtained from 30 postmortem cases with heart disease. The casts were divided into 2 groups: group I (n = 17) with abnormal and group II (n = 13) with normal right ventricular hemodynamics. Biplane cinegrams were taken in the anterolateral, anterior and long axial oblique, hepatoclavicular and sitting-up projections. The true volume of each cast was determined from its weight and specific gravity. In both groups, excellent correlations were obtained between measured and true volumes (r = 0.92 to 0.99) in all projections, although each projection overestimated the true volume (slope value less than 1). The regression equations obtained from group I were significantly different from those in group II in all views (p less than 0.025 to 0.05), with smaller mean differences and standard errors of the estimate. These data support the concept that right ventricular hemodynamics influence ventricular septal position and, therefore, LV geometry and measured volumes. Appropriate regression equations are required to allow volume calculation from multiple projections.

Cardiac Volume↗
PubMed1988

Correlation of right ventricular volume using axial angulated ventriculography to known right ventricular cast volumes in infants and children with congenital heart disease.

To calculate right ventricular (RV) volumes from biplane cineangiography obtained in nonstandard views, regression equations were developed from RV casts of known volume. Volumes were calculated using Simpson's rule from casts ranging from 2 to 42 ml from 25 postmortem specimens with various congenital heart diseases. The casts were divided into 2 groups: group 1 (n = 15) with abnormal or group 2 (n = 10) with normal RV hemodynamic measurements. Biplane cinegrams were taken in the anterolateral, anterior and long axis oblique, hepatoclavicular and sitting up projections. The true volume of each cast was determined from its weight and specific gravity. Excellent correlations were obtained between measured and true volumes (r = 0.92 to 0.96) in all projections, although each projection overestimated the true volume (slope value less than 1). The regression equations obtained from group 1 were not statistically different from those in group 2 in any view. Although the application of different regression equations is required in measuring RV volumes by multiple angulated angiography, these regression equations appear not to be affected by the hemodynamic state of the ventricle. These results are important in assessing RV volume in pediatric patients with congenital heart disease using axial angulated ventriculography.

Cineangiography↗
PubMed1988

Angiographic features associated with percutaneous balloon valvotomy for pulmonary valve stenosis.

Changes in the mobility of the pulmonary valve were determined by a retrospective review of right ventricular cineangiograms from 25 balloon pulmonary valvotomy (BV) procedures in 23 infants and children. The angiographic changes were compared with the post-BV catheter and Doppler pressure gradients across the right ventricular outflow tract. Angiographic features felt to indicate valve tearing were present following 17 of 25 procedures and included increased excursion or straightening of leaflets, localized change in leaflet motion (flail leaflet), and the presence of an additional contrast jet through the valve. There was no statistically significant relationship between any of the angiographic parameters and the pressure data. Most patients with marked increase in angiographic valve mobility had low residual right ventricular to pulmonary artery gradients. However, the absence of angiographic change was not always associated with a high residual gradient.

Catheterization↗
PubMed1988

Left ventricular systolic and diastolic function after two-stage anatomic correction of transposition of the great arteries.

Anatomic repair of transposition of the great arteries (TGA) has been developed because of concerns about right ventricular function after atrial repair by the Mustard or the Senning technique. This study assessed left ventricular systolic and diastolic function in three patients after two-stage anatomic repair. Two patients had a ventricular septal defect (one with coarctation), and the third patient had right ventricular dysfunction precluding atrial repair. All had pulmonary artery banding. The mean ages at the time of repair and catheterization were 2.75 and 4.9 years, respectively. The control group included 10 patients with insignificant or no cardiac disease. At cardiac catheterization the group with TGA had a higher mean end-diastolic volume index (110.9 +/- 4.74 ml/m2) compared to normal subjects (79.1 +/- 14.55; p less than 0.001), mean end-systolic volume index (37.3 +/- 3.69 vs 22.7 +/- 4.42; p less than 0.001), mass index (101.0 +/- 16.9 vs 68.2 +/- 12.34; p = 0.038), and stroke volume index (73.6 +/- 3.52 vs 56.5 +/- 12.1; p = 0.0027). The ejection fractions, end-diastolic and peak systolic pressures, and stresses were not different. There was no difference in the relationship between the mean rate-corrected velocity of circumferential fiber shortening and end-systolic stress for the group with TGA, but myocardial stiffness was markedly elevated (29.5 +/- 1.84 vs 10.8 +/- 2.20; p less than 0.001). Thus, this study found abnormalities of left ventricular size after two-stage anatomic repair of TGA in this group of patients with TGA.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Catheterization↗