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Biomedical subjects

R D Rowe

Publications and source records attributed to R D Rowe.

At least 73 records · Page 4Linked to original sources
PubMed1983

Serial electrocardiographic changes in healthy and stressed neonates.

Serial changes in T-wave vector and polarity were assessed in 162 electrocardiograms, 117 from 44 healthy term neonates and 45 from 17 stressed neonates. Records were taken at 5 to 8 hours, 24 to 33 hours, and 71 to 96 hours after birth. Sequential changes in both T-wave amplitude and frontal and horizontal axes were found in both groups. A lag period was noted between healthy and stressed infants when comparing changes in T-wave amplitude, with greater flattening of T-waves for longer periods of time after birth in the stressed group. The normal changes in T-wave axis over time in the horizontal and frontal planes showed a similar lag in the stressed group. Alterations of T-wave amplitude and axis alone may be markers of myocardial ischaemia in neonates but are only reliable signs after the first 24 hours of life.

Apgar Score↗
PubMed1983

Palliative right ventricular outflow tract construction for patients with pulmonary atresia, ventricular septal defect, and hypoplastic pulmonary arteries.

From December, 1977, through June, 1981, 15 patients with pulmonary atresia, ventricular septal defect, and hypoplastic pulmonary arteries underwent a palliative right ventricular outflow tract construction. In seven (Group A) this was the first surgical procedure, whereas in the remaining eight (Group B) previous systemic-pulmonary artery anastomoses had been performed. A high morbidity of the pulmonary arteries was present in Group B, resulting in part from the previous shunting procedures. The left pulmonary artery was severely hypoplastic in five patients; the right was hypoplastic in seven of the eight patients and was severely stenotic or atretic in three. All the patients in Group A survived the palliative right ventricular outflow tract reconstruction, and only one in Group B died. Almost all patients had an increase in the aortic PO2 and oxygen saturations after palliative right ventricular outflow tract construction, with a concomitant fall in hemoglobin concentration. Three of the five patients in Group A who underwent postoperative angiography were found to have proximal left pulmonary artery stenosis, and three had lesser involvement of the proximal right pulmonary artery as well. Three of the six patients in Group B who were studied postoperatively also had severe stenosis or proximal atresia of the right pulmonary artery, and three patients had stenosis and hypoplasia of the left pulmonary artery as well, two severe. Thus in no patient in this series were normal pulmonary arteries achieved by palliative right ventricular outflow tract construction will provide the potential for ultimate complete repair. The rather constant finding of severe proximal left pulmonary artery stenosis and hypoplasia in Group A is disappointing.

Adolescent↗
PubMed1982

The ECG in aortic stenosis. Value of TAVF and QV6.

Fifty patients with a mean age of 9.2 years (range, 1.2 to 17.5 years) had cardiac catheterization performed under standardized conditions plus a scalar ECG the previous day. Twenty different direct measurements and 25 derived measurements from the ECG were correlated with the resting peak systolic gradient across the aortic valve. Some of the best correlations were with the measured TAVF, TV6, QV6, and the sum of SV1 + RV6 with r values between .33 and .59. Another group of different patients with isolated aortic stenosis were studied with measurements of the important ECG segments. The r value of this "test" series was similar to that of the original group, so the groups were pooled. The best three-term regression equation involved TAVF, QV6, and the sum (SV1 + RV6), with r = .636. A scoring system was also devised to predict severity. If the TAVF is 0.1 mV or less or the TV6 is 0.3 mV or less or if there is no Q in V6, the gradient may be high. In our series, the ECG estimation of resting peak systolic gradient across the aortic valve in aortic stenosis was enhanced by the inclusion of TAVF and QV6 in the regression equation, as well as SV1 + RV6.

Adolescent↗
PubMed1982

The atrioventricular junction in the univentricular heart: a two-dimensional echocardiographic analysis.

The atrioventricular junction of 40 patients with univentricular heart was evaluated by two-dimensional echocardiography. The apical 4 chamber view optimally imaged the atrioventricular junction, and allowed determination of the type of atrioventricular connection: double inlet, common atrioventricular orifice, and absent right or left atrioventricular connection. When double inlet to 1 ventricle was demonstrated, the 4 chamber view allowed immediate comparison of the form and function of the right and left atrioventricular valves. Because anomalies of the atrioventricular valves frequently complicate the univentricular heart, two-dimensional echocardiographic assessment is a most important adjunct to the preoperative investigation of these patients.

Adolescent↗
PubMed1982

Unmet need for pediatric cardiology services and correlates of referral in Ontario, 1975-1977.

We collected data on 930 neonates with structural congenital heart disease seen during 1975-1977 at the existing pediatric cardiac referral and treatment centers in Ontario. Estimates were made of unmet need for pediatric cardiology services in Ontario. The data showed that a number of counties had significantly low referral rates and that at least 25% of the newborns with severe structural heart disease (that is, 75 newborns each year) were not seen by pediatric cardiologists, although the children would benefit from prompt assessment and rapid treatment under specialist supervision.

Cardiac Care Facilities↗
PubMed1982

Space-occupying lesions of the myocardium: role of two-dimensional echocardiography in detection of cardiac tumors in children.

Four patients with space-occupying myocardial lesions were studied using electronically focused high-resolution two-dimensional echocardiography. In two patients with clusters of high-intensity echoes at various depths on the epicardial surface, histology confirmed the diagnosis of lymphosarcoma, showing patchy, malignant infiltrates of different thickness. The remaining two patients had very different features: the lesions appeared to be intrinsic to the posterior left ventricular wall. One patient who had arrhythmias and a small encapsulated noncontractile mass had a histologically proved rhabdomyoma. In the second patient fibroma was histologically confirmed. In these two patients the position of the lesions was confirmed by angiocardiography. Two-dimensional echocardiography greatly improved delineation of space-occupying cardiac masses and is an accurate method for confirming the presence of such lesions.

Adolescent↗
PubMed1982

Mechanism of acquired right ventricular outflow tract obstruction in patients with ventricular septal defect: an angiocardiographic study.

Right ventricular outflow tract obstruction can complicate the natural history of patients with isolated ventricular septal defect. Although numerous pathologic mechanisms may be responsible for this phenomenon, it is less clear what the frequency is of each of these mechanisms in any cohort of patients studied in a single institution. We identified 20 patients with isolated ventricular septal defect from 1970 to 1981 who acquired a right ventricular outflow tract gradient of 25 mm Hg or more. They ranged in age at the initial catheterization investigation from 4 days to 23 months and at the subsequent study from 13 months to 8 years. Angiographically, 2 mechanisms were implicated in the 20 patients. Hypertrophy of right ventricular anomalous muscle bundles was identified in 19 of the 20 while hypertrophy of a malaligned infundibular septum (that is, classic tetralogy type) was identified in only 1 patient. These data indicate that acquired right ventricular outflow tract obstruction is rarely of the classic tetralogy type.

Aortic Valve↗
PubMed1982

Assessment of right ventricular function during supine bicycle exercise after Mustard's operation.

Right ventricular (RV) performance during supine bicycle exercise was evaluated by gated equilibrium nuclear angiography in 19 clinically well children with d-transposition of the great arteries (d-TGA), 6.4 +/- 2.7 years after Mustard's operation. Comparisons were made between rest and peak exercise. The mean resting ejection fraction was 44 +/- 12% (range 30-75%) and was unchanged at peak exercise. Eight children had a normal ejection fraction response, whereas 11 children had either no increase or a decrease in ejection fraction. Relative end-diastolic volumes decreased from resting values in all patients who had an abnormal ejection fraction response. Among patients whose ejection fraction increased, the end-diastolic volume increased in three, decreased in four and was unchanged in one at peak exercise. Heart rate increased 84% (range 52-135%) and systolic blood pressure increased 16% (range 0-28%) at peak exercise. There was no correlation between exercise response and age at surgery or interval since surgery. These data indicate that clinically well children after Mustard's procedure may have abnormal right ventricular function under stress, raising concerns about the ability of the right ventricle to function as the systemic ventricle.

Adolescent↗
PubMed1982

Cross-sectional echocardiographic diagnosis and subclassification of univentricular hearts: imaging studies of atrioventricular valves, septal structures and rudimentary outflow chambers.

We reviewed anatomic observations (surgical or autopsy), angiograms and echocardiograms from 44 patients with documented univentricular hearts. Thirty-three patients had univentricular heart of left ventricular type with an outflow or rudimentary chamber. Five had univentricular heart of right ventricular type, and six had univentricular heart of indeterminate types without a rudimentary chamber. Univentricular heart was correctly diagnosed by two-dimensional echocardiography in all but two of the 44 patients, including 25 of 27 double-inlet univentricular hearts, all five with absent left and all 12 with absent right atrioventricular connection. One of the two blind trabecular pouches was missed on echocardiography; the other was not seen on the angiogram but was present at autopsy. In 30 of 33 patients, univentricular heart of left ventricular type was correctly identified by imaging an anterosuperior and leftward or rightward outlet chamber, and in four of five patients with univentricular heart of right ventricular type, the anomaly was correctly identified by imaging the inferior and posterior position of the rudimentary outflow chamber near the crux of the heart. Two-dimensional echocardiography provides detailed analysis of atrioventricular connections, main chamber morphology, and rudimentary chamber size and position of noninvasive diagnosis and anatomic subclassification of univentricular hearts.

Adolescent↗
PubMed1982

The role of cava-pulmonary (Glenn) anastomosis in the palliative treatment of congenital heart disease.

The value of the cava-pulmonary anastomosis (Glenn procedure) was assessed by reviewing the entire experience with this procedure in 83 children at The Hospital for Sick Children, Toronto, from 1961 to 1980. The over-all operative mortality rate was 9.6%, but only 2% in the second half of the series. The average follow-up is 9.4 years per patient. The late mortality rate has been 20%. By actuarial analysis, 84% of survivors were alive 9 years after operation; 54% had adequate palliation and 46% had required further operation. Long-term palliation was significantly better when the anastomosis was performed after 5 years of age. A previous arterial pulmonary artery shunt had no effect on either patient or shunt survival. Patients with tricuspid atresia had a better long-term survival rate than, but similar shunt survival to, those children with transposition, single ventricle, or miscellaneous cardiac anomalies. Angiography in 36 survivors showed patent shunts in 35 and no arteriovenous fistulas. Clinical status was not related to superior vena caval pressure or angiographic findings, indicating that Glenn shunt failure is a functional problem. The procedure is most useful for patients over 5 years of age who have complex heart disease not amenable to total repair. It is also on appropriate initial procedure in young patients over 18 months of age for whom direct atrium--pulmonary artery anastomosis is proposed as the future definitive treatment.

Adolescent↗
PubMed1982

Creatine kinase isoenzymes in serum from cord blood and the blood of healthy full-term infants during the first three postnatal days.

Isoenzymes of creatine kinase (ATP:creatine phosphotransferase; EC 2.7.3.2; CK) were measured by electrophoresis in serum from cord blood and skin-puncture blood taken from 45 healthy full-term infants during the first three postnatal days. Mean total CK activities (in U/L at 30 degrees C) were 185 in cord samples, 536 in samples taken between 5--8 h postnatally, 494 between 24--33 h, and 288 in the 72-100 h samples. Values for all three isoenzymes increased to a peak over this period, with the highest values generally being found in the samples taken 5--33 h after birth; the subsequent decline was most rapid for CK-BB. Serum CK isoenzymes in cord samples and those taken at 72--100 h in the 11 babies delivered by cesarian section did not differ significantly from those of babies delivered vaginally. However the postnatal increases in total CK, CK-MM, and CK-MB (but not in CK-BB) were significantly greater in those patients born by vaginal delivery. The reasons for the increases in CK isoenzymes after birth are not clear, but our results and reported studies on the ontogeny of CK suggest that CK-MB cannot be regarded as a "cardiac-specific" isoenzyme in the neonatal period.

Alanine Transaminase↗
PubMed1981

A comprehensive scoring system for evaluating Noonan syndrome.

A multidisciplinary team assessed 23 patients with various manifestations of the Noonan syndrome, including pulmonary valve stenosis (with leaflet dysplasia), "typical" facial appearance (including hypertelorism, epicanthic folds, flat nasal bridge, and apparently low-set ears), short stature, and mental retardation. Seven patients had a family history of the syndrome. A comprehensive scoring system was devised on the basis of frequency and severity of manifestations and results of invasive and noninvasive tests in these patients and those reported in the literature. The scoring system was condensed into a score card for clinical use and validated by "blind" application to patients with isolated pulmonary valve stenosis or suspected Noonan syndrome. Use of a scoring system to diagnose a syndrome for which there is no specific diagnostic test facilitates accuracy and decreases observer bias. In the case of unusual congenital disorders it is particularly valuable for a pediatrician in general practice.

Adolescent↗
PubMed1981

Two-dimensional echocardiographic identification of hemitruncus: anomalous origin of one pulmonary artery from ascending aorta with the other pulmonary artery arising normally from right ventricle.

Two-dimensional echocardiography (2DE) was performed on a 2300 gm newborn who presented with congestive heart failure. Clinical examination suggested left-to-right shunt with pulmonary hypertension. Cardiac catheterization and angiography demonstrated origin of the right pulmonary artery (RPA) from the aorta. Retrospectively, this feature (anomalous RPA) had been present on 2DE. A second patient aged 2 years had evidence of ventricular septal defect with large left-to-right shunt early in life. Gradual development of infundibular stenosis and clinical cyanosis ensued. 2DE showed subaortic ventricular septal defect with infundibular stenosis. Cardiac catheterization and angiography confirmed tetralogy of Fallot with origin of the left pulmonary artery (LPA) from the aorta. Retrospective review of 2DE showed the anomalous LPA arising from the side of the ascending aorta.

Angiocardiography↗
PubMed1981

Right ventricular ejection fraction and volumes after mustard repair: correlation of two dimensional echocardiograms and cineangiograms.

The right ventricular ejection fractions derived from two dimensional echocardiograms and cineangiograms were compared in 24 children. All patients (aged 2.1 to 16 years) had undergone Mustard repair for transposition of the great arteries 1 to 12 years earlier. The correlation of the two methods was excellent (r = 0.977), confirming the usefulness of echocardiography for deriving ejection fraction. The volume components of the ejection fraction were less well estimated from the echocardiograms, but the ratios of end-diastolic to end-systolic volumes estimated from each method were similar.

Adolescent↗
PubMed1981

Echocardiographic features before and after the Jatene procedure (anatomical correction) for transposition of the great vessels.

Eight patients with complete transposition of the great vessels (TGA) underwent the Jatene procedure and repair of major associated anomalies. All were studied preoperatively by M-mode and two-dimensional echocardiography (2DE) and by cardiac catheterization. Six patients survived operation and were studied postoperatively by both echocardiographic methods; five also underwent cardiac catheterization and angiography. In these patients, 2DE accurately predicted the anatomic features preoperatively and provided an important adjunct to catheterization and angiocardiography.

Adolescent↗
PubMed1981

Early experience with arterial repair of transposition.

Major anomalies associated with isolated complete transposition of the great arteries (TGA) can produce systemic pressure in the left ventricle without fixed stenosis of the left ventricular outflow tract. In this situation, arterial repair may be advantageous. Eight children, 10 days to 15 years old, underwent arterial repair of TGA. Major associated anomalies included large patent ductus arteriosus, bulging intraventricular septum, ventricular septal defect (VSD), tricuspid atresia, and the Taussig-Bing type of double-outlet right ventricle. There were 2 operative deaths related to acute left ventricular failure. The survivors underwent postoperative echocardiographic, hemodynamic, and angiographic assessment; all were in sinus rhythm and well six months to 2 1/2 years after operation. Residual lesions have been frequent but mild: aortic insufficiency (5), stenosis of the right ventricular outflow tract (1), trivial VSD (1), and stenosis of the right coronary artery (1). Left ventricular function is "normal" in 4 and unchanged from moderately depressed preoperative status in 1.

Adolescent↗