Biomedical subjects

Andrew N Pelech

Publications and source records attributed to Andrew N Pelech.

11 recordsLinked to original sources

PubMed2006

Ventricular septal defect and aortic valve regurgitation: pathophysiology and indications for surgery.

As the velocity of a fluid increases a low-pressure zone is created, this is the Venturi effect and it explains the pathogenesis of aortic valve prolapse (AVP) and aortic insufficiency (AI) that is observed in a subset of patients with a ventricular septal defect (VSD). The VSDs complicated by AI are restrictive with high velocity shunting through the VSD, creating a low-pressure zone that impacts the adjacent aortic valve cusp resulting in AVP and subsequent AI. AVP and AI are therefore acquired lesions. AI is absent at birth because the forces necessary to create the low-pressure zone within the restrictive VSD do not exist in utero. The risk of development of AI increases during childhood, peaking at 5 to 10 years of age. VSD closure eliminates the low-pressure zone that is the cause of ongoing aortic valve cusp deformity and, if performed early, prevents development of AI. Patients with a subarterial VSD and AVP should undergo surgery to prevent the development of AI because this complicates about half of subarterial VSDs with AVP and spontaneous closure is rare. Patients with perimembranous VSDs with AVP should be followed with serial echocardiography and undergo VSD closure if more than trivial AI develops.

Aortic Valve Insufficiency↗

PubMed2006

The Wisconsin Pediatric Cardiac Registry: a mechanism for exploring etiologies of congenital heart defects.

On January 1, 2000, the Wisconsin Pediatric Cardiac Registry began registering families of infants born with a congenital heart defect (CHD) in Wisconsin. Pediatric cardiologists across the state developed the Registry as a database and as a research study exploring potential etiologies of CHDs. Participating pediatric cardiologists identify the infants and refer families to the Registry. Families are asked to participate by completing a comprehensive questionnaire that inquires into exposures and illnesses experienced during the 6 months prior to the pregnancy and during the pregnancy itself. A subset of families, based on the infant's diagnosis (hypoplastic left heart syndrome, conotruncal abnormalities, and Ebstein's anomaly) participates in DNA testing. This article describes the development of the Registry, family referral and participation to date, genetic advances in the etiology of CHDs, and research initiatives utilizing the data provided by families for the WPCR.

Heart Defects, Congenital↗

PubMed2005

Pulmonary thromboembolism associated with Klippel-Trenaunay syndrome.

Klippel-Trenaunay syndrome (KTS) is a rare congenital anomaly characterized by unilateral limb overgrowth, venous varicosities, and capillary malformations (port wine stains) of the affected limb or limbs. Large venous malformations such as those observed in KTS are rare, and many physicians are unfamiliar with the potential complications, which include hypercoagulability, thrombosis, and pulmonary embolism (PE). As a result, patients may suffer from delayed diagnosis of a potentially life-threatening thromboembolic event. We present 2 cases of children with KTS complicated by PE, and we review the English-language literature regarding pathophysiologic features, interventions, and outcomes of PE in the setting of KTS among both pediatric and adult patients, with emphasis on issues relevant to pediatricians.

Acute Disease↗

PubMed2005

Toward the etiologies of congenital heart diseases.

Congenital heart disease remains a significant cause of morbidity and mortality. In recent years, significant advances in molecular genetics, improved understanding of morphogenesis, recognition of specific patterning of abnormalities within and between species, and the impact of the Human Genome Project have accounted for these advances. Continued rapid developments in genomics and proteomics are anticipated. Epidemiologic investigations continue to be necessary to assess the influence of the environment on genetics. We are on the threshold of influencing the occurrence of congenital heart diseases.

Heart Defects, Congenital↗

PubMed2005

Complex aortic valve repair as a durable and effective alternative to valve replacement in children with aortic valve disease.

OBJECTIVE: This study was undertaken to determine the utility of aortic valve repair in children. METHODS: A retrospective analysis was conducted on aortic valve surgery from 1973 to 2004 at Children's Hospital of Wisconsin. RESULTS: Procedures were classified as simple repairs (blunt valvotomy, commissurotomy with or without thinning, n = 147), repair of aortic insufficiency with ventricular septal defect (n = 22), complex repairs (any combination of additional procedures including suspension of prolapsed leaflets, leaflet extensions, repair of torn or perforated leaflets, annuloplasty, reduction of sinus of Valsalva plasty, and concomitant repair of supravalvular or subvalvular stenosis, n = 57), and replacements (n = 57, 20 mechanical, 2 porcine, and 35 human valves). Freedoms from reintervention for simple repairs and repair of aortic insufficiency with ventricular septal defect at 10 years were 86% +/- 5% and 93.3% +/- 6%, respectively. For complex valve repair, freedoms from reintervention at 1, 5, and 10 years were 94% +/- 3%, 85% +/- 6%, and 44% +/- 15%, versus 96% +/- 3%, 77% +/- 9%, and 77% +/- 9% for valve replacement ( P = .3). At intermediate follow-up, patients with complex valve repair had a residual gradient of 20 +/- 21 mm Hg, and 94% were free of severe aortic insufficiency. Residual aortic stenosis ( P < .05) but not the preoperative diagnosis of combined aortic stenosis and insufficiency predicted the need for reintervention. CONCLUSION: Freedom from reintervention after complex valve repairs was not different from that after valve replacement, with acceptable residual aortic stenosis and insufficiency. Simple repairs and repair of aortic insufficiency with ventricular septal defect yielded excellent long-term freedom from reintervention.

Adolescent↗

PubMed2005

Aortic valve repair.

Aortic valve replacement options are limited in children, and all of them have disadvantages. Aortic valve repair techniques have evolved slowly and have not gained wide acceptance; however, large series using a variety of techniques demonstrate that valve repair is possible with excellent early hemodynamics and satisfactory intermediate durability. The results of aortic valve repair at the Children's Hospital of Wisconsin are presented. Simple repairs (blunt valvotomy, commissurotomy, or commissurotomy with leaflet thinning) directed at congenital aortic stenosis resulted in 86% +/- 5% freedom from reintervention at 10 years. Repair of aortic insufficiency with ventricular septal defect (VSD) resulted in 93.3% +/- 6% freedom from reoperation at 10 years. Complex repairs included a combination of techniques and yielded 5-year freedom from reintervention of 83% +/- 7% compared with 73% +/- 11% for patients undergoing aortic valve replacement (P = .62). Aortic valve repair provides an alternative to aortic valve replacement in selected patients. The utility of aortic valve repair and aortic valve replacement must be measured not only in freedom from reintervention but also in regression of left ventricular mass and exercise testing. Improvement in outcome depends on better patient selection and suitable bioprosthetic materials.

Adolescent↗

PubMed2004

Excess birth prevalence of Hypoplastic Left Heart syndrome in eastern Wisconsin for birth cohorts 1997-1999.

BACKGROUND: Hypoplastic Left Heart syndrome (HLHS) is a group of cardiac malformations involving underdevelopment of the left heart with an inability to maintain systemic circulation. Because of a clinical impression of excess HLHS prevalence, we completed a medical record review of cases born from 1997 through 1999 who were Wisconsin residents and seen at the Children's Hospital of Wisconsin (CHW). METHODS: Cases were identified either in the CHW medical records database or the Division of Pediatric Cardiology database and confirmed by echocardiogram, catheterization, surgery, or autopsy. U.S. and international surveillance systems were used to estimate population risk. Rates per 10,000 births were computed for eastern Wisconsin and four regions within this portion of the state, and compared to the estimated population risk. The same methods were used to evaluate whether rates for tetralogy of Fallot and transposition of the great arteries were elevated. RESULTS: A total of 61 cases were ascertained yielding a birth prevalence of 3.7 per 10,000 births, which was greater than the estimated population risk of 2.79. The rate for the southeast region also exceeded the expected rate. The most urban and industrialized areas had the highest rates. Rates for the other two diagnoses evaluated were not different from estimated population risks. CONCLUSIONS: Eastern Wisconsin, particularly the urban southeast region, had elevated rates of HLHS. Because of the geographic clustering of high rates, environmental factors may be associated with this finding.

Humans↗

PubMed2004

Sudden death in congenital heart disease.

Sudden cardiac death is a common mechanism of demise in association with congenital cardiac abnormalities. The varied mechanisms may include failure of the transitional circulation, arrhythmias, postoperative or perioperative complications in the neonate and coronary ischaemia, arrhythmias, sepsis, thrombosis, or pulmonary hypertensive crisis in the older child. Knowledge of the natural history of unoperated and operated forms of congenital heart disease and long term follow up with the detection and treatment of underlying hemodynamic abnormalities should improve outcomes. There are few patients with congenital cardiac anomalies that are cured and most require long term care.

Aortic Dissection↗

PubMed2004

The physiology of cardiac auscultation.

Cardiac auscultation remains a critical component of the pediatric examination and is the primary method of diagnosis for the common innocent murmurs of childhood. This article outlines the significance of auscultation and defines the skills important for the diagnosis and recognition of common cardiac murmurs in childhood. The origin of heart sounds and murmurs is reviewed, and an approach to pediatric murmur evaluation is presented. The seven innocent murmurs of childhood and adolescence are reviewed in detail. Further diagnostic evaluation and referral depends the clinician's confidence and experience in recognizing and correctly characterizing these murmurs.

Adolescent↗

PubMed2003

Completeness of state administrative databases for surveillance of congenital heart disease.

BACKGROUND: Tracking birth prevalence of cardiac defects is essential to determining time and space clusters, and identifying potential associated factors. Resource limitations on state birth defects surveillance programs sometimes require that databases already available be used for ascertaining such defects. This study evaluated the data quality of state administrative databases for ascertaining congenital heart defects (CHD) and specific diagnoses of CHD. METHODS: Children's Hospital of Wisconsin (CHW) medical records for infants born 1997-1999 and treated for CHD (n = 373) were abstracted and each case assigned CHD diagnoses based on definitive diagnostic reports (echocardiograms, catheterizations, surgical or autopsy reports). These data were linked to state birth and death records, and birth and postnatal (< 1 year of age) hospital discharge summaries at the Wisconsin Bureau of Health Information (WBHI). Presence of any code/checkbox indicating CHD (generic CHD) and exact matches to abstracted diagnoses were evaluated. RESULTS: Fifty-eight percent of cases with generic CHD were identified by state databases. Postnatal hospital discharge summaries identified 48%, birth hospital discharge summaries 27%, birth certificates 9% and death records 4% of these cases. Exact matches were found for 52% of 633 specific diagnoses. Postnatal hospital discharge summaries provided most matches. CONCLUSION: State databases identified 60% of generic CHD and exactly matched about half of specific CHD diagnoses. The postnatal hospital discharge summaries performed best in both in identifying generic CHD and matching specific CHD diagnoses. Vital records had limited value in ascertaining CHD.

Birth Certificates↗

PubMed2003

Diastolic dysfunction in an unusual case of cardiomyopathy in a child: insights from Doppler and Doppler tissue imaging analysis.

OBJECTIVES: This case report describes an unusual form of cardiomyopathy in a child with abnormalities in both ventricular relaxation and compliance. The diastolic abnormalities are well-defined using Doppler inflow velocities and Doppler tissue imaging, and the Doppler findings are correlated with intracardiac pressure measurements. This case illustrates the use of noninvasive Doppler techniques in identifying diastolic dysfunction, and it sheds additional light on the interplay of relaxation, compliance, and heart rate in creating the variable inflow Doppler patterns encountered clinically.

Cardiomyopathy, Hypertrophic↗