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Biomedical subjects

Marc Gewillig

Publications and source records attributed to Marc Gewillig.

At least 37 records · Page 2Linked to original sources
PubMed2005

Validation and application of single breath-hold cine cardiac MR for ventricular function assessment in children with congenital heart disease at rest and during adenosine stress.

PURPOSE: To validate the accuracy of ventricular function analysis using a single breath-hold real-time steady sate free precession (SSFP) cine MR method and demonstrate its application during adenosine stress imaging in children with congenital heart disease. MATERIALS AND METHODS: Twenty-eight subjects with congenital heart disease were studied (mean age 12.4 +/- 2.3 years) with MR imaging at 1.5 T. Short-axis images covering the entirety of both ventricles were acquired at rest, with a conventional segmented SSFP cine sequence acquired over multiple breath-holds and a single breath-hold real-time SSFP sequence. Seventeen subjects were given an infusion of adenosine, and the single breath-hold real-time short-axis stack was repeated during stress. Two independent observers performed the ventricular function analysis. Data was compared between the 2 acquisition methods at rest and between the single breath-hold acquisition at rest and during adenosine stress. RESULTS: There was good agreement between the multiple breath-hold and single breath-hold methods for measurement of end-diastolic volume (r = 0.95 and 0.96, p < .0001) and end-systolic volume (ESV) (r = 0.76 and 0.90, p < .0001) for the left and right ventricles respectively, and the left ventricular mass (r = 0.97, p < .0001). Adenosine was administered safely to all subjects. During stress there were significant changes in the heart rate and ESV, which led to a significant increase in cardiac output (mean 1.5 +/- 1.0 L/min, p < .001). CONCLUSION: Single breath-hold real-time SSFP cine imaging is robust and accurate in assessing cardiac function in children with congenital heart disease. An application of this method is the rapid assessment of cardiac function during adenosine stress.

Adenosine↗
PubMed2004

MR coronary angiography and late-enhancement myocardial MR in children who underwent arterial switch surgery for transposition of great arteries.

PURPOSE: To prospectively evaluate the feasibility of magnetic resonance (MR) coronary artery imaging and to define myocardial damage with late-enhancement myocardial MR imaging in children who underwent arterial switch surgery for transposition of the great arteries. MATERIALS AND METHODS: The local research ethics committee approved this study, and the subjects and/or a parent or guardian gave informed consent. Sixteen asymptomatic subjects who had undergone arterial switch surgery for transposition of the great arteries were studied (mean age, 10.8 years +/- 1.3; 11 male subjects, five female subjects). MR coronary angiography, late-enhancement MR imaging, global ventricular function, and regional wall motion were assessed. Fifteen children were awake during imaging; one was imaged with the use of general anesthetic. RESULTS: In 23 (72%) of 32 coronary arteries imaged, diagnostic-quality images of the coronary ostium and proximal coronary artery course were acquired; this increased to 100% in subjects older than 11 years. No coronary ostial stenoses were seen. In all subjects, the proximal course of the coronary arteries was visualized. Two subendocardial viability defects were detected, which corresponded to known compromise of the artery that supplied that territory at the time of surgery. Global left and right ventricular function were preserved, with no regional wall abnormalities. CONCLUSION: Diagnostic-quality MR coronary angiography is feasible in subjects who have undergone arterial switch surgery for transposition of the great arteries, with no unexpected areas of myocardial infarction detected.

Adolescent↗
PubMed2004

Stenting the neonatal arterial duct in duct-dependent pulmonary circulation: new techniques, better results.

OBJECTIVES: The goal of this study was to assess a new approach to stent the arterial duct in neonates with a duct-dependent pulmonary circulation. BACKGROUND: Previous attempts to stent the neonatal arterial duct were unsatisfactory. Learning from these failures, we speculated that covering the complete length of the duct with current low-profile stents might avoid previous problems. METHODS: Ten neonates with duct-dependent pulmonary circulations through a short straight duct were treated with stent implantation. The duct was crossed with an atraumatic 0.014-inch wire. A low-profile premounted coronary stent (outer diameter <4F, length 13 to 24 mm, diameter 3.0 to 4.0 mm) was positioned within the duct, not protected by a sheath; care was taken to cover the complete length of the duct from the aortaductal junction until well within the pulmonary trunk. RESULTS: All stents could safely be deployed with adequate pulmonary flow at early- and medium-term follow-up. There were no procedure-related complications; one patient died early from sepsis. All patients had adequate relief of cyanosis for at least three to four months. During follow-up, the pulmonary vasculature bed had grown without distortion. Acute occlusion of a stented duct was not observed. Ductal flow progressively decreased slowly over several months by luminal narrowing, until the stented duct had either become redundant or was dilated/restented or until elective staged surgery was performed. CONCLUSIONS: With current technology, complete stenting of a short straight duct is a safe and effective palliation, allowing adequate growth of the pulmonary arteries.

Cardiac Surgical Procedures↗
PubMed2004

Health status, functional abilities, and quality of life after the Mustard or Senning operation.

BACKGROUND: Life expectancy of patients who underwent atrial switch operation for the transposition of the great arteries is relatively good. However, many patients are faced with residua and sequelae, which may hamper their functioning and quality of life. This multicenter study assessed the perceived health status, functional abilities, and quality of life in long-term survivors of the Mustard or Senning operation. METHODS: A group of 89 patients (58% male) were selected from four tertiary care centers, consisting of 37 Mustard and 52 Senning operation patients. Perceived health status was measured using a linear analog scale. The educational level, employment status, New York Health Association classification, ability index, and Baecke questionnaire were used to evaluate functional abilities. Quality of life was assessed with a linear analog scale, the Satisfaction with Life Scale, and the Congenital Heart Disease-TNO/AZL Adult Quality of Life. RESULTS: Patients reported good to very good perceived health, functional capacities, and quality of life. The responses of patients with complex transposition were equivalent to those of patients with simple transposition. The most dominant concerns reported by survivors of the Mustard and Senning operations were experiences about physical limitations and worries about a current or future job or income. CONCLUSIONS: Long-term survivors after atrial inflow correction demonstrated favorable perceived health, functional status, and quality of life; these conditions were, to a large extent, comparable with the status of the general population. These outcome variables were not negatively affected by the complexity of the transposition.

Activities of Daily Living↗
PubMed2004

Educational and behavioral issues in transitioning from pediatric cardiology to adult-centered health care.

It is assumed that when they begin growing up, a child with congenital heart disease will take personal responsibility for his or her care. For this purpose, patients need sufficient knowledge on the heart defect, treatment,and measures to prevent complications. However, empirical studies indicated that the levels of knowledge and understanding of both parents and children with congenital heart disease are poor. Therefore, sound patient education is imperative, particularly when patients are transitioned from pediatric cardiology to adult congenital cardiology. In this respect, the focus of communication shifts from the parent to the young patient; moreover, education should be tailored according to the developmental level of the patient. Issues that should typically be covered by educational programs for adolescents with congenital heart disease are information on the heart defect, treatment, endocarditis, sexuality and reproduction, sports, employability and insurability, and cardiovascular risk factor. International guidelines indicate that advanced practice nurses are key in developing and implementing patient education programs during the transition from pediatric cardiology to adult-centered health care.

Adolescent↗
PubMed2004

The Contegra conduit in the right ventricular outflow tract induces supravalvular stenosis.

OBJECTIVE: We sought to evaluate the incidence and nature of pulmonary stenosis after implantation of the bovine jugular vein graft (Contegra; Medtronic, Inc, Minneapolis, Minn) in the right ventricular outflow tract. METHODS: Between May 2000 and September 2002, 58 Contegra conduits (8-22 mm) were implanted during primary (n = 27) or redo operations (n = 31) in 57 patients, with ages ranging from 2 days to 48 years (mean, 9 years). Indications were truncus arteriosus (n = 16), tetralogy of Fallot (n = 28), pulmonary replacement in the Ross operation (n = 10), and Rastelli-type repair for double-outlet right ventricle (n = 4). Echocardiography was prospectively performed by a fixed team of investigators during follow-up (mean, 22.7 +/- 10 months). A peak gradient of greater than 50 mm Hg was considered severe stenosis. RESULTS: Two patients died from Staphylococcus aureus -induced septicemia and enterococcal endocarditis after 12 days and 12 weeks, respectively. One patient died of heart failure caused by endocardial fibroelastosis after 1 year. Freedom from severe stenosis at the distal anastomosis was 91% +/- 3% at 3 months, 68% +/- 6% at 12 months, and 49% +/- 8% at 24 months. The risk of development of stenosis does not change over time. Younger age and its derivatives (graft size and indication) are significantly related to the occurrence of severe stenosis ( P < .0001). Seventeen (29%) conduits required an endovascular intervention (balloon dilatation or stent). Seven (12%) conduits were explanted (endocarditis, 2; stenosis, 5). Histologic analysis of the explanted conduits showed excessive proliferation of neointima at the level of the distal anastomosis. Valve regurgitation was observed in 9 (16%) conduits and was always secondary to dilatation in the presence of severe distal stenosis. CONCLUSION: The Contegra conduit induces a neointimal proliferation at the level of the pulmonary anastomosis. This leads to a high incidence of severe stenosis at intermediate-term follow-up.

Adolescent↗
PubMed2004

Regional right and left ventricular function after the Senning operation: an ultrasonic study of strain rate and strain.

BACKGROUND: Systemic right ventricular dysfunction is a major concern in the follow-up of patients who underwent an atrial redirection procedure for transposition (concordant atrio-ventricular and discordant ventriculo-arterial connections). No good non-invasive method is currently available for quantifying right ventricular function. AIMS: We have used ultrasonically based imaging of strain rate and strain to quantify regional deformation in the right ventricle after the Senning operation, comparing properties of regional deformation of the right ventricle with right ventricular ejection fraction as measured using magnetic resonance imaging. METHODS: In 20 asymptomatic patients who had undergone the Senning procedure, we measured peak systolic strain rate and systolic strain values in the right ventricular free wall, the septum and the left ventricular lateral wall using colour Doppler myocardial imaging, comparing the data with findings obtained in 30 healthy subjects. Global right ventricular ejection fraction was assessed using magnetic resonance imaging. RESULTS: Properties of deformation of the right ventricular free wall were reduced and homogeneous after the Senning procedure compared to normals, with significantly lower values for peak systolic strain rate and systolic strain (-1.1 +/- 0.4 vs. -2.5 +/- 0.9 s(-1); p < 0.05 and -16 +/- 7% vs. -38 +/- 13%; p < 0.05, respectively). There was a significant correlation between regional longitudinal right ventricular systolic strain values and right ventricular ejection fraction (r = -0.87, p < 0.001). In the septum, peak systolic strain rate was again reduced and homogeneous (-1.2 +/- 0.4 vs. -1.8 +/- 0.5 s(-1); p < 0.05 vs. normals). Also in the left ventricle, the lateral wall peak systolic strain rate and systolic strain values were reduced (-1.5 +/- 0.5 vs. -2.1 +/- 0.9 s(-1); p < 0.05 and -20 +/- 6% vs.-25 +/- 9%; p < 0.05, vs. normals, respectively). CONCLUSIONS: Properties of regional longitudinal deformation of the systemic right ventricle are reduced after the Senning procedure compared to normal controls, and correlate well with global right ventricular performance. These findings suggest that ultrasonic strain rate and strain imaging could be used in the non-invasive follow-up of ventricular function in these patients.

Adolescent↗
PubMed2004

Association of patent ductus arteriosus and severe hypothyroidism in term newborns: coincidence or causal?

We report on 3 term newborns with the association of patent ductus arteriosus (PDA) and severe hypothyroidism attributed to thyroid agenesis (n = 2) or feto-maternal pit-1 deficiency (n = 1). This association suggests that sufficient thyroid hormone availability is among the prerequisites for normal postnatal ductal closure. Unravelling the maturational effects of thyroid hormone on the ductus arteriosus might also be relevant in preterm infants as further studies of the perinatal thyroid axis may clarify the potential role of thyroid hormone in PDA closure in preterm infants. Based on our observation, hypothyroidism should be considered in term infants with PDA.

Ductus Arteriosus, Patent↗
PubMed2003

Pseudo-Bartter syndrome in a neonate on prostaglandin infusion.

UNLABELLED: We describe a case of iatrogenic pseudo-Bartter syndrome caused by administration of prostaglandin E1 (PGE1 alprostadil). Although the use of i.v. PGE1 is a well-established pharmacological therapy in neonates with a ductus-dependent congenital cardiopathy to ensure ductus-dependent flow, we could only find one other report on pseudo-Bartter syndrome related to PGE1 infusion. CONCLUSION: Primary Bartter syndrome is associated with endogenous increased levels of prostaglandins. Therefore, we postulate that the dose of prostaglandin E1 administered, immaturity and the genetic background are all relevant factors involved in the phenotypic presentation of iatrogenic pseudo-Bartter syndrome in this preterm infant.

Abnormalities, Multiple↗
PubMed2003

VEGF: a modifier of the del22q11 (DiGeorge) syndrome?

Hemizygous deletion of chromosome 22q11 (del22q11) causes thymic, parathyroid, craniofacial and life-threatening cardiovascular birth defects in 1 in 4,000 infants. The del22q11 syndrome is likely caused by haploinsufficiency of TBX1, but its variable expressivity indicates the involvement of additional modifiers. Here, we report that absence of the Vegf164 isoform caused birth defects in mice, reminiscent of those found in del22q11 patients. The close correlation of birth and vascular defects indicated that vascular dysgenesis may pathogenetically contribute to the birth defects. Vegf interacted with Tbx1, as Tbx1 expression was reduced in Vegf164-deficient embryos and knocked-down vegf levels enhanced the pharyngeal arch artery defects induced by tbx1 knockdown in zebrafish. Moreover, initial evidence suggested that a VEGF promoter haplotype was associated with an increased risk for cardiovascular birth defects in del22q11 individuals. These genetic data in mouse, fish and human indicate that VEGF is a modifier of cardiovascular birth defects in the del22q11 syndrome.

Animals↗
PubMed2003

A novel mutation L619F in the cardiac Na+ channel SCN5A associated with long-QT syndrome (LQT3): a role for the I-II linker in inactivation gating.

Congenital long QT syndrome type 3 (LQT3) is caused by mutations in the gene SCN5A encoding the alpha-subunit of the cardiac Na(+) channel (Nav1.5). Functional studies of SCN5A mutations in the linker between domains III and IV, and more recently the C-terminus, have been shown to alter inactivation gating. Here we report a novel LQT3 mutation, L619F (LF), located in the domain I-II linker. In an infant with prolonged QTc intervals, mutational analysis identified a heterozygous missense mutation (L619F) in the domain I-II linker of the cardiac Na(+) channel. Wild-type (WT) and mutant channels were studied by whole-cell patch-clamp analysis in transiently expressed HEK cells. LF channels increase maintained Na(+) current (0.79 pA/pF for LF; 0.26 pA/pF for WT) during prolonged depolarization. We found a +5.8mV shift in steady state inactivation in LF channels compared to WT (WT, V(1/2)=-64.0 mV; LF, V(1/2)=-58.2 mV). The positive shift of inactivation, without a corresponding shift in activation, increases the overlap window current in LF relative to WT (1.09 vs. 0.58 pA/pF), as measured using a positive voltage ramp protocol (-100 to +50 mV in 2s). The increase in window current, combined with an increase in non-inactivating Na(+) current, may act to prolong the AP plateau and is consistent with the disease phenotype observed in patients. Moreover, the defective inactivation imposed by the L619F mutation implies a role for the I-II linker in the Na(+) channel inactivation process.

Binding Sites↗
PubMed2003

The ratio of flow in the superior and inferior caval veins after construction of a bidirectional cavopulmonary anastomosis in children.

In patients who have undergone a superior cavopulmonary anastomosis, the superior caval venous flow provides the only, or the most important, pulmonary blood supply, while the inferior caval venous blood is not oxygenated, being mixed with the pulmonary venous blood before entering the systemic circulation. In healthy children, the contribution of superior caval venous flow to total cardiac output has been shown to decrease during growth. Patients who have undergone a superior cavopulmonary anastomosis, however, often have a higher oxygen saturation than predicted by the age-matched ratio of superior to inferior caval venous flows. This study was designed, therefore, to assess the ratio of flows in the superior and inferior caval veins subsequent to a superior cavopulmonary anastomosis. We carried out 18 magnetic resonance imaging studies with velocity-mapping and heart catheterisations so as to assess the contribution of superior caval venous flow to total cardiac output. Patients were divided into 3 groups according to their age. There were five aged from 8 to 24 months, eight aged from 24 to 48 months, and five older than 48 months. No significant difference could be found in the ratios of superior-to-inferior caval venous flow, nor of superior caval venous-to-systemic flow, between the 3 groups. The ratio of venous flows was 0.89 +/- 0.34 in those aged from 8 to 24 months, 1.09 +/- 0.42 in those from 24 to 48 months, and 1.25 +/- 0.27 in the older patients (F analysis of variance 1.06, p 0.37). The ratio of superior caval venous-to-systemic flow was 0.46 +/- 0.08 in the youngest patients, 0.50 +/- 0.09 in those aged from 24 to 48 months, and 0.55 +/- 0.05 in the older patients (F analysis of variance 0.76, p 0.49). These findings suggest that the hemodynamics of a cavopulmonary anastomosis may affect the normal decrease of superior caval venous flow with age. This could be related to a redistribution of flow, with a proportionally higher flow to the head and upper body after construction of a superior cavopulmonary anastomosis. Since increasing cyanosis and progressive exercise intolerance are the main indications for creation of a total cavopulmonary connection, these findings should be taken into account when determining the timing for completion of the Fontan circulation.

Cardiac Catheterization↗