Publications by authors named "Caldarone C"

Objective: We sought to define patient characteristics, outcomes, and associated factors after mitral valve replacement in children.

Methods: We included 104 children undergoing at least one mitral valve replacement between 1980 and 2003 and reviewed clinical records. Competing-risks methodology was used to determine time-related prevalence and associated risk factors after initial mitral valve replacement for death and repeat replacement.

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Background: In the early postoperative period, the neonatal myocardium undergoes sparse apoptotic cell loss ( approximately 1% of myocytes). Because apoptosis is preceded by events associated with mitochondrial dysfunction, the fraction of myocytes with preapoptotic mitochondrial changes has important clinical implications (eg, postoperative myocardial dysfunction). My colleagues and I therefore hypothesized that postoperative apoptotic myocytes represent a tip of the iceberg, with more myocytes upstream with apoptosis-related mitochondrial dysfunction (ARMD).

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Objectives: Apoptosis is a mechanism for deletion of injured or obsolete cells that is distinct from necrosis and mediated by mitochondrial release of cytochrome c caspase activation. Because myocardial apoptosis is a part of normal fetal and postnatal maturation, we hypothesize that neonatal myocardium is more vulnerable to undergo myocardial apoptosis than mature myocardium after cardioplegic arrest.

Methods: Newborn and mature lambs (n = 5 in each group) underwent cardiopulmonary bypass, antegrade crystalloid hyperkalemic cardioplegic arrest for 60 minutes, and a 6-hour recovery period.

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Background: Prosthesis survival, growth, and functional status after initial mechanical mitral valve replacement (MVR) in children <5 years of age are poorly defined.

Methods And Results: The experience of the Pediatric Cardiac Care Consortium (45 centers, 1982 to 1999), which included 102 survivors after initial MVR, was analyzed. Median follow-up: 6.

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Objective: Myocardial apoptosis is observed after various cardiac injuries and is also a normal part of fetal cardiac development and early postnatal maturation. Cardioplegic arrest and reperfusion result in ischemic injury and oxidative stress, known triggers of apoptosis. Because the neonatal heart is in a proapoptotic state, we hypothesize that apoptosis is triggered after cardioplegic arrest in neonatal myocardium.

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The progressive nature of obstruction in the left ventricular outflow tract (LVOT) is hypothesized to be related to the complex relationship between anatomic substrate, genetic predisposition, local shear stress, and the response to injury. Consequently, recurrent obstruction after resection of subaortic membranes as well as more complex forms of LVOT obstruction (eg, tunnel-like stenosis) require aggressive resection to provide unobstructed egress of blood from the left ventricle. The modified Konno procedure is well suited to provide maximal enlargement of the entire LVOT with preservation of aortic valve function.

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Objectives: To identify risk factors for excessive bleeding after coronary artery bypass graft (CABG) procedures and to quantify the outcomes related to this complication.

Design: We conducted a case-control study to identify risk factors for hemorrhage following CABG surgery and a historical cohort study to quantify outcomes of hemorrhage.

Setting: The cardiothoracic surgery service of a university hospital.

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Background: Complex left ventricular outflow tract (LVOT) obstruction with normal aortic valve function requires aggressive resection in the subaortic region and preservation of the aortic valve. The modified Konno procedure allows generous exposure of the LVOT from the left ventricular apex to the inter leaflet trigones of the aortic valve. Widespread use of this procedure has been limited by concern over injury to the aortic valve, the conduction system, and possibility of residual ventricular septal defect (VSD).

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Numerous metabolic adaptations occur in the heart after birth. Important transcription factors that regulate expression of the glycolytic and mitochondrial oxidative genes are hypoxia-inducible factors (HIF-1alpha and -2alpha) and nuclear respiratory factor-1 (NRF-1). The goal of this study was to examine expression of HIF-1alpha, HIF-2alpha, and NRF-1 and the genes they regulate in pre- and postnatal myocardium.

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Background: Small-sized homografts are often not available, making the use of surgically reduced cryopreserved homograft conduits appealing.

Methods: From January 1993 to January 2000, 21 large homografts were size-reduced by excising one leaflet and were implanted in the pulmonary circulation. Valve function was compared with 21 children-matched for weight, homograft size, and year of operation-who received a standard homograft.

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To test the hypothesis that coronary flow and coronary flow reserve are developmentally regulated, we used fluorescent microspheres to investigate the effects of acute (6 h) pulmonary artery banding (PAB) on baseline and adenosine-enhanced right (RV) and left ventricular (LV) blood flow in two groups of twin ovine fetuses (100 and 128 days of gestation, term 145 days, n = 6 fetuses/group). Within each group, one fetus underwent PAB to constrict the main pulmonary artery diameter by 50%, and the other twin served as a nonbanded control. Physiological measurements were made 6 h after the surgery was completed; tissues were then harvested for analysis of selected genes that may be involved in the early phase of coronary vascular remodeling.

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Background: Short- and long-term outcomes after prosthetic mitral valve replacement (MVR) in children aged <5 years are ill-defined and generally perceived as poor. The experience of the Pediatric Cardiac Care Consortium (45 centers, 1982 to 1999) was reviewed.

Methods And Results: MVR was performed 176 times on 139 patients.

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Mechanical support of the pediatric cardiac patient.

Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu

January 2000

Increased understanding of the anatomical nuances of congenital heart defects, improved methods of myocardial preservation, and advances in surgical techniques have led to improved results and need for postoperative mechanical support in patients undergoing congenital heart surgery. However, there remains a small portion of patients with myocardial or pulmonary failure that can can be rescued by intelligent use of mechanical support. The most widely used form of mechanical support is extracorporeal membrane oxygenation (ECMO), which has been adapted for use in congenital heart patients as well as patients with respiratory failure.

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Patients with total anomalous pulmonary venous drainage (TAPVD) presenting with associated complex cardiac anatomy have a markedly less favorable prognosis when compared to patients with isolated TAPVD. The impact of associated cardiac lesions on the pathophysiology of TAPVD and the wide array of operative strategies for surgical palliation is discussed. Copyright 2000 by W.

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Objective: To evaluate the age dependence of variables predictive of pulmonary valve prosthesis replacement, we conducted the following analysis.

Methods: Retrospective analysis of 945 operations in 726 patients undergoing placement of pulmonary valve prostheses was performed. Age was identified as a strong independent predictor of valve failure.

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Background: The operative mortality rate for the first 400 Fontan procedures at this institution was 15% but declined to 4% for the next 100 procedures.

Methods: The cases of 100 consecutive patients receiving the Fontan procedure and associated with this change in mortality rate were reviewed to determine associations.

Results: The mortality rate in the first and second 50 patients was 16% and 0%, respectively.

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We present a 1,600 g infant who underwent successful balloon aortic valvuloplasty from the right carotid artery approach. A simple technique to facilitate access to the left ventricle and expedite the procedure is described. Issues unique to performing balloon aortic valvuloplasty on such a small child are discussed.

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Objective: Extracardiac conduits between the right ventricle and pulmonary arteries commit patients to multiple reoperations. We reviewed our experience with stent implantation in obstructed conduits.

Methods: Between 1990 and 1997, stents were implanted across 43 conduits.

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Background: Recent reports have cited improving results for surgical management of isolated total anomalous pulmonary venous drainage. Complex cases (with other cardiac anomalies) are less frequently reported and are associated with higher mortality.

Methods: Retrospective review identified 170 consecutive patients treated for total anomalous pulmonary venous drainage from 1982 to 1996: 44 cases were "complex" (with significant associated cardiac lesions) and 126 cases were "simple.

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Background: Progressive stenosis of the pulmonary veins after repair of total anomalous pulmonary venous drainage is frequently refractory to surgical therapy.

Methods: Retrospective review of 170 consecutive patients treated for total anomalous pulmonary venous drainage identified 13 patients with postrepair pulmonary vein stenosis. Preoperative and operative data were analyzed to define the patterns of progression and efficacy of surgical techniques.

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Background: Brief episodes of ischemia can precondition myocardium. Ischemic preconditioning (PC) has been proposed as an adjuvant method of improving myocardial protection during cardiac surgery. It is unknown whether CPB without an episode of ischemia generates the PC response.

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Freeman et al. (1993) have recently introduced a new index measuring isovolumic relaxation in the in situ left ventricle. This index, called the R-average, shows less variability than the traditionally used monoexponential time constant (tau), and could therefore represent an alternative measure of isovolumic relaxation during different physiological or pathophysiological interventions.

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As an increasingly aged population undergoes cardiac surgery, myocardial protective strategies must address the fundamental differences between adult and senescent myocardium. In a test of the hypothesis that senescent myocardium is less tolerant of cardioplegic arrest, adult (0.5 to 1.

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