Raising heart-healthy children

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

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

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

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

Transcatheter treatment of congenital heart disease

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27854/1/0000265.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

Use of Balloon-Tipped Catheters in the Critically Ill Child

A retrospective study of our experience in the placement of 19 consecutive balloon-tipped catheters in the pulmonary artery of 18 children disclosed that the procedure can be performed with relative ease in the intensive care unit without the aid of fluoroscopy. Insertion of the catheters was not associated with any serious complications. Catheter malfunction, however, occurred in 9 of 18 patients: balloon rupture in 6 and clot formation in 3. Comparison of pulmonary capillary pressure through a balloon-tipped catheter and venous pressure through a central venous line indicates that, in the absence of significant pulmonary disease requiring high positive end expiratory pressure, or significant left heart dysfunction, a central venous pressure line is frequently adequate for monitoring right heart pressures and as a guidance to fluid therapy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67256/2/10.1177_000992288202100302.pd

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

Temporal relationship between instantaneous pressure gradients and peak‐to‐peak systolic ejection gradient in congenital aortic stenosis

ObjectiveWe sought to identify a time during cardiac ejection when the instantaneous pressure gradient (IPG) correlated best, and near unity, with peak‐to‐peak systolic ejection gradient (PPSG) in patients with congenital aortic stenosis. Noninvasive echocardiographic measurement of IPG has limited correlation with cardiac catheterization measured PPSG across the spectrum of disease severity of congenital aortic stenosis. A major contributor is the observation that these measures are inherently different with a variable relationship dependent on the degree of stenosis.DesignHemodynamic data from cardiac catheterizations utilizing simultaneous pressure measurements from the left ventricle (LV) and ascending aorta (AAo) in patients with congenital valvar aortic stenosis was retrospectively reviewed over the past 5 years. The cardiac cycle was standardized for all patients using the percentage of total LV ejection time (ET). Instantaneous gradient at 5% intervals of ET were compared to PPSG using linear regression and Bland‐Altman analysis.ResultsA total of 22 patients underwent catheterization at a median age of 13.7 years (interquartile range [IQR] 10.3‐18.0) and median weight of 51.1 kg (IQR 34.2‐71.6). The PPSG was 46.5 ± 12.6 mm Hg (mean ± SD) and correlated suboptimally with the maximum and mean IPG. The midsystolic IPG (occurring at 50% of ET) had the strongest correlation with the PPSG (PPSG = 0.97(IPG50%)–1.12, R2 = 0.88), while the IPG at 55% of ET was closest to unity (PPSG = 0.997(IPG55%)–1.17, R2 = 0.87).ConclusionsThe commonly measured maximum and mean IPG are suboptimal estimates of the PPSG in congenital aortic stenosis. Using catheter‐based data, IPG at 50%–55% of ejection correlates well with PPSG. This may allow for a more accurate estimation of PPSG via noninvasive assessment of IPG.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140042/1/chd12514.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/140042/2/chd12514_am.pd