Raising heart-healthy children

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75188/1/j.1442-200x.1999.01151.x.pd

Balloon valvuloplasty for critical aortic stenosis in the newborn: Influence of new catheter technology

AbstractBetween 1986 and July 1990, balloon valvuloplasty was attempted in eight newborns (<28 days of age) with isolated critical aortic valve stenosis. Balloon valvuloplasty could not be successfully accomplished in any of the three infants presenting before 1989. Since March 1989, when improved catheter technology became available, all five neonates presenting with critical aortic stenosis were treated successfully by balloon valvuloplasty. A transumbilical approach was utilized in all four infants in whom umbilical artery access could be obtained. One newborn who was 25 days of age underwent transfemoral balloon valvuloplasty.Balloon valvuloplasty was immediately successful in all five newborns, as evidenced by a decrease in valve gradient and improvement in left ventricular function and cardiac output. Peak systolic gradient was reduced by 64% from 69 ± 8 to 25 ± 3 mm Hg (p = 0.005). Left ventricular systolic pressure decreased from 128 ± 9 to 95 ± 9 mm Hg (p = 0.02) and left ventricular end-diastolic pressure decreased from 20 ± 2 to 11 ± 1 mm Hg (p = 0.02). Moderate (2+) aortic regurgitation was documented in two infants after valvuloplasty. The time from first catheter insertion to valve dilation averaged 57 ± 14 min (range 26 to 94) and the median length of the hospital stay was 4 days.With the use of recently available catheters, the transumbilical technique of balloon valvuloplasty can be performed quickly, safely and effectively in the newborn with critical aortic stenosis. It does not require general anesthesia, cardiopulmonary bypass or a left ventricular apical incision and it preserves the femoral arteries for future transcatheter intervention should significant aortic stenosis recur

Hemodynamic abnormalities in response to supine exercise in patients after operative correction of tetrad of fallot after early childhood

The exercise hemodynamic values in two groups of patients with repaired tetrad of Fallot (eight patients with some residual pulmonary insufficiency and seven patients without insufficiency) were compared with values in seven patients with trivial pulmonary stenosis who had not been operated on. The patients with tetrad of Fallot underwent surgery after age 8 years and all had a good hemodynamic repair (no shunts and a right ventricular systolic pressure at rest of less than 60 mm Hg). Exercise increased the right ventricular outflow tract gradient by the same magnitude in all three groups of patients. However, both surgically treated groups experienced impaired cardiac pump function on supine exercise (that Is, a lower than anticipated cardiac Index for the amount of oxygen consumed and a significant decrease in stroke Index). Exercise also caused both groups with repair to have a decrease in stroke Index and a concomitant increase in right ventricular end-diastolic and pulmonary wedge pressures; in contrast, the patients with pulmonary arterial stenosis had an Increase in stroke index and a concomitant decrease in right ventricular end-diastolic and pulmonary wedge pressures.These findings Indicate that an impaired cardiac response to supine exercise can occur in patients In whom Intracardlac repair of tetrad of Fallot was performed after early childhood, even though they have had a good hemodynamic repair. In addition, the impaired cardiac response to supine exercise in these patients was probably due largely to an altered myocardial compliance rather than to either residual pulmonary stenosis or pulmonary insufficiency.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24294/1/0000560.pd

Prediction of steady‐state verapamil plasma concentrations in children and adults

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110108/1/cptclpt1982144.pd

Transcatheter Atrial Septal Defect Closure: Preliminary Experience with the Rashkind Occluder Device

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72836/1/j.1540-8183.1989.tb00751.x.pd

Serial Changes in Norepinephrine Kinetics Associated With Feeding Dogs a High-Fat Diet

J Clin Hypertens (Greenwich). 2010;12:117–124. © 2009 Wiley Periodicals, Inc. The role of increased sympathetic nervous system (SNS) activity in the pathogenesis of obesity hypertension and insulin resistance is controversial. Eight dogs were instrumented and fed a high-fat diet (HFD) for 6 weeks. Dogs were evaluated for changes in weight, blood pressure, insulin resistance, and norepinephrine (NE) kinetics using a two-compartment model. The HFD resulted in weight gain, hypertension, and insulin resistance. During the 6 weeks of the HFD, although plasma NE concentration trended toward increasing ( P =.09), SNS, assessed by NE kinetic studies, significantly increased ( P =.009). Within 1 week of starting the HFD, NE release into the extravascular compartment (NE 2 ) increased from 3.44±0.59 μg/mL to 4.87±0.80 μg/mL ( P <.01) and this increase was maintained over the next 5 weeks of the HFD (NE 2 at week 6 was 4.66±0.97 μg/mL). In addition to the increased NE 2 there was also a significant increase in NE clearance ( P =.04). There were significant correlations between the increase in NE 2 and both the development of insulin resistance and hypertension. This study supports the hypothesis that activation of the SNS plays a pivotal role in the metabolic and hemodynamic changes that occur with weight gain induced by HFD.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78633/1/j.1751-7176.2009.00230.x.pd

Fluorescence spectroscopy of normal and follicular cancer samples from human thyroid

An autofluorescence analysis has been performed on healthy as well as tumour thyroid tissue samples to distinguish follicular cancer from normal thyroid. Complete spectra and synchronous spectra have been recordered from properly stored samples. Fluorescence bands located at 350 nm and 400 nm has been observed in the analysed cancer samples

Volumetric real-time particle-based representation of large unstructured tetrahedral polygon meshes

In this paper we propose a particle-based volume rendering approach for unstructured, three-dimensional, tetrahedral polygon meshes. We stochastically generate millions of particles per second and project them on the screen in real-time. In contrast to previous rendering techniques of tetrahedral volume meshes, our method does not need a prior depth sorting of geometry. Instead, the rendered image is generated by choosing particles closest to the camera. Furthermore, we use spatial superimposing. Each pixel is constructed from multiple subpixels. This approach not only increases projection accuracy, but allows also a combination of subpixels into one superpixel that creates the well-known translucency effect of volume rendering. We show that our method is fast enough for the visualization of unstructured three-dimensional grids with hard real-time constraints and that it scales well for a high number of particles

Clinical and hemodynamic follow-up of left ventricular to aortic conduits in patients with aortic stenosis

To assess the long-term results of left ventricular outflow tract reconstruction utilizing an apical left ventricular to aortic valved (porcine) conduit the clinical and hemodynamic data were reviewed from 24 patients who had placement of an apico-aortic conduit. Eighteen of the patients are asymptomatic and taking no cardiac medications. Three patients were reoperated on, one patient 1.5 years after his original operation for subacute bacterial endocarditis and two patients 3 to 4 years after their original operation for severe conduit valve insufficiency. None of the patients is taking anticoagulants and no thromboembolic events have occurred. Postoperative catheterization has been performed 1 to 1.5 years (mean 1.2) after repair in 15 of 21 patients. The rest left ventricular outflow tract gradient has decreased from 102.5 ± 20 mm Hg preoperatively to 14.8 ± 9.9 mm Hg postoperatively (probability [p] < 0.001). Some degree of conduit obstruction was demonstrated by catheter passage in 11 of the 15 patients. In these 11 patients, the obstruction occurred at three distant sites: at the egress of the left ventricle in 9, at the porcine valve in 5 and at the aortic to conduit junction in 1. Isometric exercise in five and supine bicycle exercise in six patients increased the left ventricular outflow tract gradient by 2.5 ± 1.1 and 20.8 ± 11.8 mm Hg, respectively, despite an increase in cardiac index of 1 ± 0.3 and 3.7 ± 0.4 liters/min per m2, respectively. The data suggest that a left ventricular to aortic conduit is an effective form of therapy for severe left ventricular outflow tract obstruction