Biomedical subjects

Stephen M Paridon

Publications and source records attributed to Stephen M Paridon.

10 recordsLinked to original sources

PubMed2006

Longitudinal assessment of cardiovascular exercise performance after pediatric heart transplantation.

BACKGROUND: No existing longitudinal data document exercise performance after pediatric heart transplantation. We report the exercise performance findings from the longitudinal study of pediatric heart transplantation patients and the association of aerobic capacity with echocardiographic measures of graft function. METHODS: We performed a retrospective analysis of 28 children after heart transplantation who underwent 87 exercise tests and echocardiograms. Subjects exercised using graded cycle or treadmill protocols. Maximal oxygen consumption (VO2), physical working capacity, peak heart rate, and anaerobic threshold were evaluated. To measure systolic and diastolic function, shortening fraction and mitral valve pressure half-time (PHT) respectively, were obtained by echocardiography. RESULTS: The average age at transplantation was 10.9 +/- 5.6 years, at initial exercise test was 13.8 +/- 5.0 years, and at final exercise test was 15.8 +/- 5.2 years. Percent-predicted values at the initial exercise test were VO2, 59.3%; physical working capacity, 60.2%; and peak heart rate, 75.8%; these remained similarly decreased at the final exercise test. Shortening fraction and PHT were within normal limits, but PHT was significantly greater at final test (p < 0.05). The relationship of VO2% with time was statistically significant, described by a quadratic equation that included initial VO2% and time from heart transplantation. This relationship remained significant when the shortening fraction (p < .05) but not PHT was added as a covariate in the equation. CONCLUSIONS: Exercise performance after pediatric heart transplantation is impaired and, despite an initial improvement, declines over time. This can be explained by increasing diastolic dysfunction independent of donor graft age. If confirmed, these findings point the direction to further research aimed at limiting this aerobic capacity decline after heart transplantation.

Adult↗

PubMed2006

Clinical stress testing in the pediatric age group: a statement from the American Heart Association Council on Cardiovascular Disease in the Young, Committee on Atherosclerosis, Hypertension, and Obesity in Youth.

This statement is an updated report of the American Heart Association's previous publications on exercise in children. In this statement, exercise laboratory requirements for environment, equipment, staffing, and procedures are presented. Indications and contraindications to stress testing are discussed, as are types of testing protocols and the use of pharmacological stress protocols. Current stress laboratory practices are reviewed on the basis of a survey of pediatric cardiology training programs.

Clinical Protocols↗

PubMed2006

Relationship of patient and medical characteristics to health status in children and adolescents after the Fontan procedure.

BACKGROUND: After the Fontan procedure, patients are at risk for suboptimal health status related to their complex healthcare experience, physiological limitations, medical complications, and guarded long-term prognosis. METHODS AND RESULTS: In the Pediatric Heart Network cross-sectional study of Fontan survivors 6 to 18 years of age, parents completed the Child Health Questionnaire, and scores were related in multivariable analysis to patient and medical characteristics obtained from medical record review. For 537 patients (mean age at study, 11.9 years; 60% male) with a median age at Fontan of 2.8 years (range, 0.7 to 14.6 years), parent-reported patient morbidities included deficits in vision in 33%, speech in 27%, and hearing in 7%, as well as problems with attention in 46%, learning in 43%, development in 24%, behavior in 23%, anxiety in 17%, and depression in 8%. Child Health Questionnaire summary scores were significantly lower than the US population sample for Physical Functioning (mean Z score, -0.47+/-1.19; P<0.001) and Psychosocial Functioning (-0.28+/-1.08; P<0.001). Parent-reported medical conditions and long-term and current medical problems explained the greatest amount of variation in the Physical Functioning scores. Parent-reported patient conditions, including behavior, learning, anxiety, and attention problems and depression, explained the greatest amount of variation in the Psychosocial Functioning scores. Lower family income had a negative impact on both Physical and Psychosocial Functioning. CONCLUSIONS: There are deficits in health status in children and adolescents after the Fontan procedure. Strategies to address this problem might emphasize coordinated and effective prevention, detection, and management of noncardiac and psychosocial conditions, as well as specific targeting of patients from low-income households.

Adolescent↗

PubMed2006

Exercise performance in children and adolescents after the Ross procedure.

OBJECTIVES: The Ross procedure is increasingly utilized in the treatment of aortic valvar disease in children and adolescents. Our purpose was to compare pre- and post-operative exercise state in this population. METHODS: We included patients who underwent the Ross procedure at our institution between January, 1995, and December, 2003, and in whom we had performed pre- and post-operative exercise stress tests. We used a ramp bicycle protocol to measure consumption of oxygen and production of carbon dioxide. Cardiac output was estimated from effective pulmonary blood flow by the helium acetylene re-breathing technique. RESULTS: We studied 26 patients, having a median age at surgery of 15.7 years, with a range from 7.5 to 24.1 years. The primary indication for surgery in two-thirds was combined aortic stenosis and insufficiency. Median time from the operation to the post-operative exercise stress test was 17.4 months, with a range from 6.7 to 30.2 months. There was a trend toward lower maximal consumption of oxygen after the procedure, at 36.3 plus or minus 7.6 millilitres per kilogram per minute (83.9% predicted) as opposed to 38.6 plus or minus 8.4 millilitres per kilogram per minute (88.5% predicted, p equal to 0.06). Patients after the procedure, however, had significantly increased adiposity, so that there was no difference in maximal consumption of oxygen indexed to ideal body weight before and after the operation. In 20 of the patients, aerobic capacity improved or was stable after the operation. There was no post-operative chronotropic impairment. CONCLUSIONS: In the majority of patients following the Ross procedure, exercise performance is stable and within the normal range of a healthy age and sex matched population, despite sedentary lifestyles and increased adiposity.

Adolescent↗

PubMed2005

Late neurodevelopmental outcome after repair of total anomalous pulmonary venous connection.

Objective We sought to define the neurodevelopmental status of school-aged survivors of total anomalous pulmonary venous connection repaired during infancy. Methods All school-aged survivors of total anomalous pulmonary venous connection repair performed at a single institution were eligible. Thirty children returned for neurologic examination and neurodevelopmental testing. Results The median age at total anomalous pulmonary venous connection repair was 16 days (range, 1-141 days), and age at testing was 11 years (range, 6-19 years). Pulmonary venous return was supracardiac in 14 patients, infracardiac in 12 patients, cardiac in 3 patients, and mixed in 1 patient. Preoperative obstructed total anomalous pulmonary venous connection was present in 6 patients. Circulatory arrest was used in all repairs, with a median duration of 35 minutes (range, 17-55 minutes). At follow-up, microcephaly (head circumference <5%) was present in 28%. Neuromuscular examination was suspect or abnormal in 27%. Mean Full-scale IQ (95.3 +/- 18.5) and Verbal IQ (98.6 +/- 20.2) were not different from population norms, but Performance IQ (92.3 +/- 16.9) was significantly lower than population norms ( P = .02). Fine motor skills and visual-motor coordination were significantly impaired ( P < .01 for Grooved Pegboard and Test of Visual-Motor Integration). Patients with total anomalous pulmonary venous connection also had difficulty with tests of attention (Test of Everyday Attention for Children, P < .01), but results of tests of memory function were not significantly different from population norms. Conclusions School-aged survivors of infant total anomalous pulmonary venous connection repair exhibit a significant incidence of neurodevelopmental difficulties. Fine motor function, visual-motor integration, and attention are the most commonly affected domains. Evaluation of these children is indicated to identify those who are at risk for learning disabilities and who could benefit from early intervention.

Actuarial Analysis↗

PubMed2004

Using health-related quality of life measures to predict cardiac function in survivors exposed to anthracyclines.

PURPOSE: As the number of pediatric cancer survivors increases, so does the number of survivors previously exposed to anthracyclines as part of their cancer therapy. Because screening is costly, some have suggested that health-related quality of life (HRQL) measures might be useful in focusing screening tests on those patients with cases most likely to display positive findings. This study reports on the predictive ability of HRQL measures to detect patients with abnormalities on serial cardiac testing. METHODS: Using 127 patients from the ACE-Inhibitor after Anthracycline (AAA) Trial, this study compared serial measures of the Short Form-36 (SF-36; for ages > 13 years) and Child Health Questionnaire-Child Form 87 (CHQ-CF87; for ages < or = 13 years) to serial cardiac performance tests including echocardiographic shortening fraction, left ventricular end systolic wall stress (LVESWS), LVESWS-index, and maximal cardiac index (MCI; a measure of cardiac output at peak exercise). RESULTS: Generally, there was no clinically or statistically significant correlation between any HRQL measure and any cardiac function measure except between MCI and vitality and physical functioning. For each of these measures, the correlation between MCI was statistically significant (P < .006), but each HRQL subscale could explain no more than 7% of the variation in MCI. HRQL measures were not predictive of any other cardiac function measure. CONCLUSION: HRQL measures should not be used in isolation as a screen for cardiac function abnormalities in patients exposed to anthracylines who already have a mild degree of ventricular dysfunction. Patient history appears to be no substitute for cardiac testing in this cohort.

Adolescent↗

PubMed2004

Enalapril to prevent cardiac function decline in long-term survivors of pediatric cancer exposed to anthracyclines.

PURPOSE: To determine whether an angiotensin-converting enzyme (ACE) inhibitor, enalapril, prevents cardiac function deterioration (defined using maximal cardiac index [MCI] on exercise testing or increase in left ventricular end-systolic wall stress [LVESWS]) in long-term survivors of pediatric cancer. PATIENTS AND METHODS: This was a randomized, double-blind, controlled clinical trial comparing enalapril to placebo in 135 long-term survivors of pediatric cancer who had at least one cardiac abnormality identified at any time after anthracycline exposure. RESULTS: There was no difference in the rate of change in MCI per year between enalapril and placebo groups (0.30 v 0.18 L/min/m(2); P =.55). However, during the first year of treatment, the rate of change in LVESWS was greater in the enalapril group than in the placebo group (-8.59 v 1.85 g/cm(2); P =.033) and this difference was maintained over the study period, resulting in a 9% reduction in estimated LVESWS by year 5 in the enalapril group. Six of seven patients removed from random assignment to treatment because of cardiac deterioration were initially treated with placebo (P =.11), and one has died as a result of heart failure. Side effects from enalapril included dizziness or hypotension (22% v 3% in the placebo group; P =.0003) and fatigue (10% v 0%; P =.013). CONCLUSION: Enalapril treatment did not influence exercise performance, but did reduce LVESWS in the first year; this reduction was maintained over the study period. Any theoretical benefits of LVESWS reduction in this anthracycline-exposed population must be weighed against potential side effects from ACE inhibitors when making treatment decisions.

Adolescent↗

PubMed2004

Exercise testing in pediatrics.

This article discusses exercise physiology and its application in the pediatric population. This article discusses exercise physiology and its application in the pediatric population. The authors briefly review the normal physiologic response to exercise. They then discuss populations in which exercise testing is most useful, the indications and contraindications for graded exercise, and the usual parameters that are measured during testing. Finally, the authors review some of the recent data on exercise performance in specific pediatric populations.

Adolescent↗

PubMed2002

Preoperative pulmonary venous obstruction affects long-term outcome for survivors of total anomalous pulmonary venous connection repair.

BACKGROUND: Early outcomes after repair of total anomalous pulmonary venous connection continue to improve; however, little information is available concerning long-term functional status and quality of life. METHODS: One hundred patients underwent isolated total anomalous pulmonary venous connection repair at The Children's Hospital of Philadelphia between 1983 and 2001. Medical records were reviewed and a standardized questionnaire was administered to guardians of survivors. RESULTS: Median age at repair was 15.5 days (range, 1 to 563 days). Overall hospital mortality was 14%, decreasing from 19% before 1995 to 5% after 1995. At 15 years after repair, actuarial survival was 84% and freedom from late death or reintervention for hospital survivors was 85%. At a median follow-up of 5.9 years (range, 0 to 17.7 years) 64% of guardians described their child's overall health as excellent, 27% good, 9% fair, and 0% poor. With regard to school performance, 40% of children were characterized as above average, 29% average, 4% below average, and 27% were in special education classes or had repeated grades. By multivariable logistic regression, the presence of associated chromosomal or noncardiac syndromes and pulmonary venous obstruction were found to be significant factors with regard to parental assessment of both overall health and school performance. CONCLUSIONS: The majority of children who undergo isolated total anomalous pulmonary venous connection repair can expect an excellent long-term functional outcome. Factors present before operation, such as pulmonary venous obstruction and associated anomalies, can influence overall health and school performance in the long term.

Actuarial Analysis↗

PubMed2002

Pneumatosis intestinalis after pediatric thoracic organ transplantation.

OBJECTIVE: To review and describe pneumatosis intestinalis (PI) in children who have undergone thoracic organ transplantation and evaluate potential risk factors. METHODS: We retrospectively reviewed abdominal radiographs obtained from June 1992 through September 2000 in all pediatric (age <21 years) thoracic organ recipients who survived at least 1 week after transplantation. In this group, a case was defined as an episode of radiographically confirmed PI; those without PI were assigned as controls. Variables analyzed included demographic data, gastroenteritis history (stool cultures or symptoms of gastroenteritis), and transplant-related factors (ie, graft type, rejection history, immunosuppression regimen). Significance was defined as P <.05. RESULTS: Over this 8-year period, PI occurred in 8 (7%) of 116 patients (0.86% annual risk). No child had >1 diagnosed episode of PI. Of these 8 cases, 7 presented with 1 or more abdominal symptoms. Three of these children had rotavirus antigen isolated in their stool, 2 others were noted to have stool positive for Clostridium difficile toxin, and in the other 3, no pathogen was identified. All cases were treated with a regimen of intravenous antibiotics and total parenteral nutrition. There were no deaths; however, 1 patient developed an Aspergillus pulmonary infection during his course of antibiotic therapy, and another underwent an exploratory laparotomy without bowel resection. Significant risk factors included black race (unadjusted odds ratio: 16), younger age at presentation (age <5 years; unadjusted odds ratio: 9), higher steroid dose (steroid dose >0.5 mg/kg/d; unadjusted odds ratio: 7), and a higher tacrolimus level at presentation (tacrolimus level >1; unadjusted odds ratio: 6). PI did not occur with a steroid dose <0.4 mg/kg/d. Variables not associated with increased risk for developing PI included gender, graft type, total white blood cell count, recent antibiotic use, concurrent use of an antimetabolite, cytomegaloviral infection, past use of extracorporeal membrane oxygenation, and graft rejection history. CONCLUSIONS: Significant risk factors for the development of PI in our pediatric thoracic organ transplantation population included black race, younger age, higher daily steroid dosing, and a high tacrolimus level at presentation. In the children diagnosed with PI, there were no related deaths, significant gastrointestinal sequelae, or complications. These findings suggest that in this population, PI will often have a benign course when treated aggressively, and that steroid dosing should be reduced to <0.5 mg/kg/d whenever possible.

Age Factors↗