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Biomedical subjects

R D Rowe

Publications and source records attributed to R D Rowe.

At least 37 records · Page 2Linked to original sources
PubMed1987

Abnormal endothelial factor VIII associated with pulmonary hypertension and congenital heart defects.

In patients with pulmonary hypertension associated with congenital heart defects, ultrastructural abnormalities are observed in endothelial cells, which suggest heightened metabolic function. If endothelial production of the von Willebrand factor (vWF) is increased, this may be associated with abnormal interactions with platelets leading to worsening of the pulmonary hypertension. We therefore evaluated vWF in 30 patients with pulmonary hypertension (25 with congenital heart defects) and in 30 individuals with normal pulmonary arterial pressure (12 with congenital heart defects). We measured the antigenic (vWF: Ag) and biologic (VWF: rist) activity of vWF in plasma and assessed endothelial vWF: Ag directly by an immunoperoxidase stain applied to lung biopsy tissue. Because of considerable variance and small size, the group of five patients with pulmonary hypertension and without congenital heart defects were excluded from statistical analyses. Patients with pulmonary hypertension and congenital heart defects had significant higher vWF: Ag levels than individuals with normal pulmonary arterial pressure without congenital heart defects (p less than .05), whereas values in those with normal pressure and congenital heart defects were intermediate. In lung biopsy tissue available from 29 patients in this study and from 11 others we previously reported, immunostain of pulmonary arterial endothelium for vWF was intense (suggesting increased production) in 29 of 32 with pulmonary hypertension and congenital heart defects and in only one of eight with normal pulmonary arterial pressure and congenital heart defects (p less than .01). Only three patients with congenital heart defects and pulmonary hypertension and increased vWF: Ag, however, had increased vWF: rist. Compatible with this discrepancy was a loss of vWF high-molecular weight forms as determined by both crossed immunoelectrophoresis and multimeric analysis. Our results suggest that increased vWF in most patients with congenital heart defects and pulmonary hypertension is associated with increased production of a biologically deficient molecule lacking high-molecular weight forms.

Adolescent↗
PubMed1987

Surgical experience with the modified Fontan procedure.

During a 10 year period 109 patients (3 months to 47 years old) underwent modifications of the Fontan procedure for repair of classic tricuspid atresia (TA) (n = 58), univentricular atrioventricular connection (UVH) (n = 38), or other complex malformations (CM) (n = 13). Among patients with TA, an atriopulmonary connection was used in 19 (33%) and incorporation of the right ventricle with the Björk modification and with a right atrial-to-right ventricular valved conduit was used in 20 (34%) and in 19 (33%), respectively. Three of the latter 19 also underwent a combined Fontan-switch procedure. The hospital mortality rate was 13.8% (70% confidence limits, 9.3% to 18.3%) for patients with TA, 28.9% (70% confidence limits, 21.3% to 37.0%) for patients with UVH, and 7.7% (70% confidence limits, 0% to 15.4%) for patients with CM. Multivariate analysis identified with the following variables as risk factors for both early and late deaths: diagnosis of UVH, previous pulmonary artery banding (PAB), and postrepair right atrial pressure, and, in patients with TA, the use of a direct atriopulmonary connection (all variables, p less than .05). Morphometric lung biopsy scores were not different in patients with PAB, implicating the role of ventricular hypertrophy rather than pulmonary vascular disease as the mechanism for the adverse effect of PAB. Right atrial pressure was a predictor of serious late cardiac symptoms, which were present in 10% of eligible patients (p = .032). This review demonstrates a survival advantage with modifications of the Fontan procedure that incorporate the hypoplastic right ventricle in patients with TA.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1987

Critical aortic stenosis. Survival and management.

The factors associated with survival in 40 neonates (age less than 28 days) with critical aortic stenosis undergoing either open (22 patients) or closed (18 patients) transventricular aortic valvotomy were reviewed. Significant adverse correlates with survival included evidence of poor perfusion preoperatively (low pH, greater than Grade 2/6 soft ejection systolic murmur) and marked congestive heart failure (hepatomegaly, cardiomegaly, elevated left atrial pressure). Congenital mitral stenosis (anulus less than 11 mm), a small aortic anulus (less than 6.5 mm), and failure to achieve an adequate aortic orifice (greater than 6 mm), at operation were identified as factors associated with increased mortality. Initial perioperative survival was better with closed aortic valvotomy. However, there was no significant difference in overall operative survival between closed (9/18, 50%) and open (8/22, 36%) aortic valvotomy (p = 0.26). The incidence of early reoperation (less than 1 year of age) was greater in perioperative survivors undergoing closed valvotomy (7/13, 54%) rather than open valvotomy (1/10, 10%) (p less than 0.05). In conclusion, long-term survival among patients with critical neonatal aortic valve stenosis remains disturbingly low (13/40, 32%) and has not significantly improved over the past 20 years.

Aortic Valve↗
PubMed1986

Radionuclide angiographic evaluation of ventricular function in isolated congenitally corrected transposition of the great arteries.

Eight asymptomatic patients (mean age 19 years, range 7 to 32) with congenitally corrected transposition of the great arteries (CCTGA) underwent equilibrium gated radionuclide angiocardiography at rest and during supine bicycle exercise to assess systemic (morphologic right) and pulmonary (morphologic left) ventricular function. Five patients had normal intracardiac hemodynamic values, 2 had trivial atrioventricular valve regurgitation and 1 patient had trivial pulmonary ventricular outflow tract obstruction. Average exercise duration was 11 +/- 1 minute, with limitation due only to fatigue. At peak exercise, heart rate increased 225% and systolic blood pressure 152% over the rest value. Pulmonary ventricular ejection fraction at rest was 51 +/- 3% (mean +/- standard error of the mean); it did not change significantly at peak stress, 53 +/- 2%. Systemic ventricular ejection fraction was 48 +/- 4% at rest and increased to 64 +/- 4% at peak exercise (p less than 0.01). Count-based volume changes for the pulmonary chamber showed no significant change in end-diastolic or systolic counts at peak exercise (109 +/- 8% and 106 +/- 9% of rest value, respectively). However, end-diastolic counts decreased 13% (87 +/- 3% of rest value) and end-systolic counts 34% (62 +/- 7% of rest value) at peak exercise in the systemic ventricle. These data suggest normal systemic and impaired pulmonary ventricular function in patients with congenitally corrected transposition of the great arteries unaccompanied by significant associated lesions. These findings have important clinical implications in the setting of complex congenital heart disease in patients in whom a morphologic right ventricle functions as the systemic pumping chamber. Despite the pulmonary ventricular dysfunction, symptoms were not apparent at rest or during exercise.

Adolescent↗
PubMed1986

Cross-sectional echocardiography in the evaluation of aortic valve prolapse associated with ventricular septal defect.

Twenty consecutive patients with ventricular septal defect and aortic valve prolapse were evaluated by cross-sectional echocardiography. Angiographic confirmation was available in all and surgical confirmation was found in 17. In 19, the right coronary cusp was involved and appeared to plug the defect in the precordial long- and short-axis cut. The cusp was deformed and appeared to pivot from the crest of the interventricular septum. In all 19 angiography demonstrated prolapse of the right cusp. Noncoronary cusp prolapse was observed in two by cross-sectional echocardiography and in six by angiocardiography. The ventricular septal defect was perimembranous in 14 and doubly committed subarterial in six by echocardiography. Angiographically, the ventricular septal defect was felt to be perimembranous in 15 and doubly committed in five. Aortic regurgitation was detected by Doppler interrogation in seven, all of whom underwent plication of the right coronary cusp. Angiographic evidence of regurgitation was noted in 11, but four were mild and possibly related to catheter position. Five patients had associated muscular right ventricular outflow tract obstruction and three had a subaortic ridge. Combined cross-sectional and pulsed Doppler echocardiography provide a reliable assessment of right coronary cusp prolapse associated with a ventricular septal defect. Noncoronary cusp prolapse appears more difficult to detect. This technique should help optimize the management of patients by providing a means of early detection prior to the development of aortic regurgitation.

Adolescent↗
PubMed1986

Severe obstruction to systemic blood flow in congenitally corrected transposition (discordant atrioventricular and ventriculo-arterial connexions): an analysis of 14 patients.

The more common associated cardiac anomalies in any cohort of patients with discordant atrioventricular and ventriculo-arterial connexions (congenitally corrected transposition) include ventricular septal defect, left ventricular (subpulmonary) outlet obstruction, and displacement and/or dysplasia of the morphologically tricuspid valve. There is scant mention in the literature of severe obstruction to systemic blood flow at aortic valve level or beyond in these hearts. The present study reviews those pertinent morphological-clinical and follow-up data on 14 patients with congenitally corrected transposition and aortic valve atresia (one patient); aortic arch interruption or aortic arch atresia (two patients) and coarctation of the aorta (11 patients). All but one patient (the patient with aortic valve atresia) had a perimembranous ventricular septal defect. Mild outflow tract obstruction of the morphologically left ventricle was identified in one patient. Nine patients, however, demonstrated a significant structural and functional disturbance (Ebstein-like with dysplasia) of the systemic morphologically tricuspid valve. No patient in this series was identified with isolated aortic coarctation.

Adolescent↗
PubMed1986

High persistence rate of established coronary artery lesions secondary to Kawasaki disease among a panethnic Canadian population.

The incidence of resolution of proximal coronary artery lesions subsequent to Kawasaki disease over an 11-year period was studied retrospectively. In 28 patients proximal coronary artery lesions were identified by two-dimensional echocardiography or angiography at 1 to 3 months after disease onset. Follow-up data were adequate in 27 patients, 17 of whom were boys; 18 were white, two black, four Oriental (non-Japanese), and three of East Indian origin. Age at onset of Kawasaki disease ranged from 11 weeks to 9 years (mean 2.5 years). Coronary artery lesions were categorized as ectatic (internal diameter greater than 3 mm in those less than 5 years of age) or aneurysmal (internal lumen of a segment one and one-half times larger than an adjacent segment). Resolution was assessed by two-dimensional echocardiography or angiography during a follow-up period of 3 months to 11 years (mean 2.7 years). Apparent resolution (vessel diameter less than 3 mm) of coronary artery lesions occurred in four (15%) patients--one with aneurysmal lesions, three with ectatic lesions--all within 1 year of disease onset. Eight patients developed myocardial infarction; one of these patients died. The resolution rate was less than previously reported. This high rate would warrant closer attention to the state and sequelae of coronary artery lesions, including obstructive coronary artery disease, in follow-up assessments.

Aneurysm↗
PubMed1986

Subaortic stenosis, the univentricular heart, and banding of the pulmonary artery: an analysis of the courses of 43 patients with univentricular heart palliated by pulmonary artery banding.

Subaortic stenosis is well known to complicate the clinical course of patients with single ventricle or univentricular hearts, and we have previously suggested that the development of subaortic stenosis in such patients may be causal to and/or accelerated by previous banding of the main pulmonary trunk. To further define the relationship between banding of the pulmonary artery in patients with univentricular hearts and the development of subaortic stenosis, we examined the morphologic substrate and timing of the development of subaortic stenosis in 43 patients seen at our institution from January 1, 1970, through June 30, 1985. These 43 patients include all patients in this period with an unequivocal univentricular heart whose longitudinal data was available for follow-up. We excluded patients who died within 1 week of surgery, patients lost to follow-up, and patients with evidence of subaortic stenosis before banding. Thirty-one of 43 patients (72.1%) developed subaortic stenosis subsequent to banding of the main pulmonary artery. The mean age at banding of those patients who developed subaortic stenosis was 0.21 years, and subaortic stenosis was recognized at a mean age of 2.52 years. For the specific cohort of patients whose ventricular morphology was a main chamber of left ventricular type supporting the pulmonary artery and a rudimentary right ventricle supporting the transposed aorta (32 patients), 27 developed subaortic stenosis (84.4%). Subaortic stenosis in the classic form of single ventricle usually results from progressive restriction of a wholly muscular interventricular communication. Banding of the pulmonary artery by producing myocardial hypertrophy undoubtedly accelerates the potential for subaortic stenosis in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomyopathy, Hypertrophic↗
PubMed1986

Sleep in Pierre Robin syndrome.

Eight patients (aged 8 to 22 years) with the Pierre Robin syndrome underwent sleep studies. Seven demonstrated significant although minor degrees of increased sleep disturbances and apneas, and less time spent in the rapid-eye-movement (REM) stage of sleep. One patient who had previously undergone mandibular corrective surgery had major sleep abnormalities (central apnea index of 81.7 although an obstructive sleep apnea index of only 1.9). The patients had small mandibles, as demonstrated by lateral cephalometric roentgenography, and mildly increased right ventricular diastolic dimensions, as shown by M-mode echocardiography. Snoring was present in all of these patients and in 13 of 22 patients questioned from our Pierre Robin clinic. We conclude that minor abnormalities in sleep, mandibular size, and right ventricular size persist well into adolescence in the majority of patients with Pierre Robin syndrome. These appear to be clinically insignificant; however, a small percentage of such patients may continue to have major sleep disturbances.

Adolescent↗
PubMed1986

Congenital aortico-right atrial communications. The dilemma of differentiation from coronary-cameral fistula.

Four cases of an unusual form of aortico-right atrial communication are described. All patients were asymptomatic but had an atypical continuous murmur on examination. A distinctive appearance was noted on the angiograms, with a large tortuous tunnel noted superior to the left sinus of Valsalva, passing posterior to the aortic root before terminating near the right atrial-superior vena caval junction. This structure was readily identified by two-dimensional echocardiography. The defect was successfully closed surgically in three of four patients. The presence of normal major coronary arteries and absence of any small myocardial coronary branches from the tunnel argues against the structure being a coronary-cameral fistula and supports the diagnosis of aortico-right atrial tunnel.

Adolescent↗
PubMed1986

Synthetic patch angioplasty for repair of coarctation of the aorta: experience with aneurysm formation.

Patch graft angioplasty is an accepted technique for the repair of some forms of coarctation and for recoarctation. Since 1970, 63 patients at our institution underwent 65 operations for repair of coarctation (ages 3 days to 32 years); in 27 it was the initial operation and 38 needed surgery for recoarctation. Average follow-up was 3.5 years (range 3 months to 14 years). There was one death, 20 patients with persistent hypertension, and eight patients with a persistent arm/leg pressure gradient (14 to 30 mm Hg at rest). Five patients required reoperation, two for recoarctation and three for aneurysm formation. The aneurysms were found on routine chest x-rays 3, 3.7, and 13.5 years after surgery. All aneurysms were repaired with left heart bypass in which a Dacron tube graft was used without complications. Synthetic patch angioplasty to repair coarctation was effective; however, aneurysm formation was a late complication in 5% of our patients. All patients undergoing patch repair should be followed on a yearly basis to allow early detection of aneurysms.

Adolescent↗
PubMed1986

Pulmonary artery endothelial abnormalities in patients with congenital heart defects and pulmonary hypertension. A correlation of light with scanning electron microscopy and transmission electron microscopy.

Scanning electron microscopy and transmission electron microscopy were applied to lung biopsy specimens from patients with congenital heart defects, and pulmonary artery endothelium was analyzed for alterations in surface characteristics and intracytoplasmic composition which might reflect abnormal function. The patients were divided into four groups distinguished by increasing severity of pulmonary vascular changes on light microscopy graded both morphometrically and by the Heath-Edwards classification; group 1, normal vasculature or only abnormal extension of muscle into peripheral arteries; group 2, medial hypertrophy; group 3, medial hypertrophy +/- decreased artery number + intimal hyperplasia; group 4, decreased artery number + occlusive intimal hyperplasia. On scanning electron microscopy, the pulmonary artery endothelial surface in group 1 patients was "crinkled" or "corduroy-like", i.e., composed of narrow, even ridges; in groups 2 and 3, it was "cable-like", i.e., comprised of deep intertwined ridges; in group 4 it was "chenille" in texture, i.e., high ridges alternated with low, uneven, and twisted ones. There was significant increased density of surface microvilli in groups 2 and 3 patients when compared to groups 1 and 4 (p less than 0.05 for each comparison). On transmission electron microscopy pulmonary artery endothelial cells in groups 2 and 3 patients were also characterized by a significant increase in the volume density of rough endoplasmic reticulum (p less than 0.01) and microfilament bundles (p less than 0.05). The coarse endothelial surface characteristics associated with pulmonary vascular changes may result in abnormal interaction with blood elements and release of vasoactive substances. The increased microvilli, rough endoplasmic reticulum, and microfilament bundles in patients with moderate but not advanced arterial changes suggest a phase where increased endothelial metabolic function and alterations in the cytoskeleton may also contribute to heightened pulmonary vascular reactivity.

Actin Cytoskeleton↗
PubMed1985

Kawasaki disease: Canadian update.

Kawasaki disease, or mucocutaneous lymph node syndrome, is a multisystem disorder that affects young children. Between 1979 and 1982, 357 patients from 15 university pediatric centres in Canada were reported to have the disease. The diagnosis of Kawasaki disease is based on six clinical features, including fever, conjunctivitis, cracked lips, reddening and swelling of the hands and feet, rash and cervical lymphadenopathy. A scoring system is described that may help predict the development of cardiovascular complications. Coronary artery involvement can be recognized early by two-dimensional echocardiography. Anti-inflammatory therapy, principally with acetylsalicylic acid, is indicated in the acute phase and antithrombotic treatment in the subacute and chronic phases of the disease if coronary artery aneurysms have developed. Prolonged follow-up for patients with aneurysms is necessary. The length of follow-up for patients without aneurysms will depend on the results of studies on patients with Kawasaki disease after they reach adulthood.

Adult↗
PubMed1985

Pulmonary valve morphology after balloon dilatation of pulmonary valve stenosis.

Percutaneous balloon valvuloplasty (BV) for pulmonic valve stenosis (PS) is increasingly becoming a nonsurgical alternative in patient management. However, the mechanism by which BV dilates the obstructive lesion has not been firmly established. We have had the opportunity to examine the effects of BV in the setting of PS and present two illustrative cases documenting the morphology after BV of the stenotic bicuspid and tricuspid pulmonary valve.

Adolescent↗