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Biomedical subjects

Steven D Colan

Publications and source records attributed to Steven D Colan.

At least 55 records · Page 3Linked to original sources
PubMed2004

Cardiovascular outcomes of pediatric seroreverters perinatally exposed to HAART: design of a longitudinal clinical study.

Seroreverters (uninfected children of HIV-infected mothers) have exhibited left ventricular (LV) dysfunction. Mitochondrial toxicity associated with in utero or postnatal exposure to highly active antiretroviral therapy (HAART) is a possible mechanism. Adult and animal models have demonstrated associations between LV abnormalities, cardiomyopathy, and components of HAART. Yet, outcomes in children are poorly understood. In this study, we explore HAART-associated LV abnormalities in seroreverters exposed to HAART (n = 144) or never exposed (n = 252). Subjects are drawn from the Women and Infants Transmission Study and the Pediatric Pulmonary and Cardiovascular Complications of HIV Study, respectively. Data include (1) echocardiographic studies of LV structure and function and (2) serologic cardiac biomarkers (cardiac troponin, probrain natriuretic peptide, high-sensitivity C reactive protein), both collected during the first month of life, and again at 6, 12, 24, 36, and 48 months postnatally. Planned analyses include several regression models. At this time, we have access to data for all 252 unexposed children, and 53 exposed subjects are enrolled. The cohorts are similar in terms of gender and race and the recruited subjects are representative of all eligible subjects in terms of exposure to HAART. Recruitment will continue into 2006.

Adult↗
PubMed2004

Recombinant human growth hormone treatment for dilated cardiomyopathy in children.

OBJECTIVE: Dilated cardiomyopathy (DCM) is one of the most common causes of heart failure among children and is often progressive despite maximal medical therapy. Heart failure is characterized by a number of neurohormonal abnormalities, including derangements in the growth hormone (GH)/insulin-like growth factor-1 (IGF-1) signaling axis. Decreased serum levels of GH, which acts on cardiac myocytes primarily through IGF-1, are associated with impaired myocardial growth and function, which can be improved with restoration of GH/IGF-1 homeostasis. In animal models and among human adults with heart failure attributable to DCM, treatment with GH results in acquisition of left ventricular (LV) mass and improved LV function, through a combination of mechanisms. We undertook this study to determine the effects of recombinant human GH on LV function and mass among children with stable LV dysfunction attributable to DCM. METHODS: We performed a prospective, single-center, randomized, partially blinded, crossover trial among children 1 to 19 years of age with DCM and cardiac dysfunction of > or =6-month duration. After enrollment, patients were randomly assigned to receive treatment for 6 months with either conventional therapy (determined by the patient's primary cardiologist) plus recombinant human GH (0.025-0.04 mg/kg per day), administered as daily subcutaneous injections, or conventional therapy alone. Patients were then crossed over to the other treatment strategy for 6 months. The primary outcome measure was change in LV shortening fraction (SF). Other echocardiographic indices of LV function, somatic growth, and somatotropic/thyroid hormone levels were also monitored. RESULTS: Only 8 of an intended 15 patients were enrolled, because of a combination of factors. Two patients withdrew during the study as a result of declining LV function requiring transplantation. LV SF did not change significantly during GH treatment, although both LV SF and LV SF z score were higher 6 months after cessation of GH treatment than at baseline. LV ejection fraction increased during GH therapy to a degree that approached significance. Height and weight percentiles for age increased significantly during GH therapy and remained higher 6 months after treatment. Annualized height velocity during GH treatment (13.7 +/- 3.3 cm/year, >97th percentile for all patients) was significantly higher than that after GH discontinuation (3.2 +/- 3.5 cm/year). Serum levels of IGF-1 and IGF-binding protein-3 were significantly higher after 6 months of GH treatment and 6 months after discontinuation of GH treatment than at baseline. There were no adverse events related to GH treatment. DISCUSSION: In this prospective, single-center, randomized, partially blinded, crossover trial, recombinant human GH was administered to 8 pediatric patients with stable chronic heart failure secondary to DCM. Because of unanticipated difficulty enrolling eligible patients, the study was underpowered to detect changes in our primary outcome measure of the magnitude we projected. Nevertheless, we did observe several notable cardiovascular effects of GH treatment, including a trend toward improved LV ejection fraction during the course of GH treatment and significantly improved LV SF, SF z score, and LV end systolic stress z score 6 months after discontinuation of GH treatment (relative to baseline values). Given the fact that levels of IGF-1, the primary myocardial effector of GH signaling, remained significantly higher 6 months after GH treatment than at baseline, the improvement in LV functional indices 6 months after discontinuation of therapy may represent progression or perpetuation of a GH treatment effect. In addition to its cardiovascular effects, GH therapy was associated with significant acceleration of somatic growth. The benefits of GH were not associated with significant attributable side effects, although 2 patients developed progressive LV dysfunction during the study and underwent cardiac transplantation.

Adolescent↗
PubMed2003

Familial restrictive cardiomyopathy with skeletal abnormalities.

A family is described in which 5 of 9 living children were found to have restrictive cardiomyopathy associated with skeletal muscle and orthopedic abnormalities. In the absence of another identifiable etiology, a genetic cause for restrictive cardiomyopathy in this family is probable. Consistent with the poor prognosis encountered for children with restrictive cardiomyopathy, 2 children in this family died, whereas a third was symptomatic by age 3 years.

Cardiac Catheterization↗
PubMed2003

The incidence of pediatric cardiomyopathy in two regions of the United States.

BACKGROUND: Population-based data on the incidence of pediatric cardiomyopathy are rare because of the lack of large, prospective studies. METHODS: Since 1996 the Pediatric Cardiomyopathy Registry sponsored by the National Heart, Lung, and Blood Institute has collected data on all children with newly diagnosed cardiomyopathy in New England and the Central Southwest region (Texas, Oklahoma, and Arkansas) of the United States. We report on all children in these regions who received this diagnosis between 1996 and 1999. RESULTS: We identified 467 cases of cardiomyopathy, for an overall annual incidence of 1.13 per 100,000 children (95 percent confidence interval, 1.03 to 1.23). The incidence was significantly higher among infants younger than 1 year old than among children and adolescents who were 1 to 18 years old (8.34 vs. 0.70 per 100,000, P<0.001). The annual incidence of cardiomyopathy was lower among white children (upper-bound estimate, 1.06 cases per 100,000) than among black children (lower-bound estimate, 1.47 per 100,000; P=0.02) and higher among boys than among girls (1.32 vs. 0.92 per 100,000, P<0.001). The incidence also varied significantly by region: 1.44 cases per 100,000 in New England and 0.98 per 100,000 in the Central Southwest region (P<0.001). When categorized according to type, dilated cardiomyopathy made up 51 percent of the cases, hypertrophic cardiomyopathy 42 percent, and restrictive or other types 3 percent; 4 percent were unspecified. There was no significant difference in the incidence rates according to the year. CONCLUSIONS: The estimated incidence of pediatric cardiomyopathy in two large regions of the United States is 1.13 cases per 100,000 children. Most cases are identified at an early age, and the incidence varies according to sex, region, and racial or ethnic origin.

Adolescent↗
PubMed2003

Noninvasive serial evaluation of myocardial mechanics in pressure overload hypertrophy of rabbit myocardium.

BACKGROUND: The determination of progression from afterload mismatch to myocardial failure in small animals requires invasive monitoring to assess ventricular pressure. OBJECTIVE: We sought to (1) validate the noninvasive determination of blood pressure using optical plethysmography, and (2) determine the time course and progression from afterload mismatch to myocyte failure in neonatal rabbits with coarctation (aortic banding at 7-10 days of life) compared to normal rabbits. METHODS AND RESULTS: Comparison of continuous arterial pressure determined by optical plethysmography with high-fidelity intraarterial recording was performed in nine animals. An accuracy of 5.9 +/- 4.7 and 9.2 +/- 6.9 mm Hg for systolic and diastolic blood pressure was noted. Fourier analysis confirmed similar frequency components. Simultaneous transthoracic echocardiography and optical plethysmography were serially performed in 33 banded and 13 control animals. Load-dependent and -independent measures of myocardial function were obtained. Midwall contractility, initially normal, showed a gradual significant deterioration (0.22 +/- 1.68 [week 3] to -1.36 +/- 1.24 [week 6]; Z-scores). CONCLUSIONS: This novel noninvasive method for determination of myocardial mechanics allows for serial evaluation of cardiac function and the determination of the time course from compensated hypertrophy to myocyte failure.

Analysis of Variance↗
PubMed2003

Clinical outcomes and utility of cardiac catheterization prior to superior cavopulmonary anastomosis.

OBJECTIVES: We sought to characterize the outcomes of routine catheterization prior to superior cavopulmonary anastomosis and to determine if some patients were unlikely to benefit from catheterization and thus might be evaluated preoperatively with noninvasive methods alone. BACKGROUND: Congenital heart disease patients with single ventricle physiology undergo routine echocardiography and cardiac catheterization prior to superior cavopulmonary anastomosis to determine anatomic and hemodynamic suitability for this procedure. METHODS: We performed a retrospective review of all infants (n = 114) evaluated for potential superior cavopulmonary anastomosis at our institution from January 1997 to June 2000. RESULTS: Patients' median age was 5.5 months. Full echocardiograms were obtained in 79 patients (69%). At catheterization a total of 41 interventions were performed in 35 patients (31%). Twenty-seven patients (24%) were transfused, 18 patients (17%) required cardiac intensive care unit admission, and median length of stay following catheterization was 1 day (range 0 to 22). Complications occurred in 28 patients (25%), most transient. Of 51 patients who had complete echocardiograms without indication for catheterization, none subsequently had significant interventions and only 2 had new findings at catheterization. Three candidates were excluded from operation; all 111 others underwent successful procedures and survived to hospital discharge. CONCLUSIONS: Interventions were frequent at catheterization prior to superior cavopulmonary anastomosis, but transient complications, transfusion, intensive care unit admission, and prolonged hospital length of stay were common. For patients in whom no issues indicating need for catheterization are identified by echocardiogram, routine catheterization rarely results in new information or intervention. These patients may be more safely evaluated preoperatively using exclusively noninvasive techniques.

Adolescent↗
PubMed2003

Usefulness of the pediatric electrocardiogram in detecting left ventricular hypertrophy: results from the Prospective Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted HIV Infection (P2C2 HIV) multicenter study.

BACKGROUND: A shortcoming of the pediatric electrocardiogram (ECG) appears to be its inability to accurately detect left ventricular hypertrophy (LVH). This study prospectively assesses the usefulness of the pediatric ECG as a screening modality for LVH. METHODS: Concomitant echocardiograms and ECGs from a large cohort of children who were exposed to the human immunodeficiency virus (HIV; uninfected) and children who were infected with HIV were compared. By use of the values of Davignon et al, qualitative determination of LVH and quantitative criteria for LVH (RV6, SV1, RV6+SV1, QV6, and Q(III) >98% for age, R/SV1 <98% for age, and [-]TV6) were compared to body surface area adjusted for left ventricular (LV) mass z score. Results were then stratified according to weight and weight-for-height z scores. New age-adjusted predicted values were then constructed from children of a mixed race who were HIV-uninfected, < or =6 years old, and similarly assessed. RESULTS: The sensitivity rate was <20% for detecting increased LV mass, irrespective of HIV status; the specificity rate was 88% to 92%. The sensitivity rate of the individual criteria ranged from 0 to 35%; the specificity rate was 76% to 99%. Test sensitivities remained low when stratified by weight and weight-for-height z scores. Areas under the receiver operator characteristic curves were between 0.59 and 0.70, also suggesting poor accuracy of the ECG criteria. By use of new age-adjusted predicted values, the sensitivity rate decreased to <17%, and the specificity rate increased to 94% to 100%. CONCLUSION: The ECG is a poor screening tool for identifying LVH in children. Sensitivity is not improved with revision of current criteria.

Child, Preschool↗
PubMed2003

Serum cardiac troponin and subclinical cardiac status in pediatric chronic renal failure.

BACKGROUND: Patients with uremia often have elevated serum cardiac troponin T (cTnT) even without clinical heart damage. Pediatric patients are ideal for studies of the relationship between uremia and heart disease because they are unlikely to have cardiac risk factors other than uremia. OBJECTIVE: To determine the relationship between uremia and cTnT levels. DESIGN: Echocardiograms and blood chemistry results were obtained from 50 pediatric patients with chronic renal failure and without clinical heart disease. Levels of cTnT were tested for correlation with cardiac dysfunction. In multivariate analysis, biochemical aspects of renal disease and its treatment were tested for correlation with cardiac dysfunction. RESULTS: Forty-nine patients had cardiovascular abnormalities, including increased left ventricular function and mass, elevated heart rate and blood pressure, and reduced LV afterload. LV contractility was inversely correlated with cTnT level (r = -0.36). Higher cTnT also correlated with higher serum creatine kinase-MB mass, lower serum parathyroid hormone, higher blood urea nitrogen and bicarbonate levels, and the use of diuretics, but not with higher cardiac troponin I. Left ventricular contractility was inversely related to serum creatinine, phosphorus, and the use of beta-blockers. CONCLUSIONS: Elevated cTnT levels are not artifactual, but are genuine indicators of cardiomyocyte damage. Cardiac damage, indicated by either elevated cTnT or low LV contractility, is related to uremia, deranged calcium and phosphorus metabolism, and bicarbonate levels. Serum cTnT and LV contractility identify subclinical cardiac damage that could be treated to hopefully reduce cardiovascular morbidity and mortality in this high-risk population.

Adolescent↗
PubMed2002

Long-term enalapril therapy for left ventricular dysfunction in doxorubicin-treated survivors of childhood cancer.

PURPOSE: A common late effect of doxorubicin therapy for childhood cancer is reduced left-ventricular (LV) wall thickness resulting in elevated LV afterload and depressed LV function. Many children are given angiotensin-converting enzyme inhibitors, which have been studied primarily in adults. We document the long-term effects of angiotensin-converting enzyme inhibitors in doxorubicin-treated survivors of childhood cancer. PATIENTS AND METHODS: In this retrospective study, we reviewed records of 18 children who had regular echocardiographic examinations during enalapril therapy (mean age at cancer diagnosis, 8 years; mean time between completion of doxorubicin therapy and start of enalapril, 7 years; median follow-up since the start of enalapril, 10 years). RESULTS: Over the first 6 years of enalapril therapy, there was progressive improvement toward normal values in LV dimension, afterload, fractional shortening, and mass, but all these parameters deteriorated between 6 and 10 years. LV wall thickness deteriorated throughout the study period, as did LV contractility and systolic blood pressure. Diastolic blood pressure fell slightly. By 6 years on enalapril, all six patients who had had congestive heart failure at the start of enalapril therapy had either died or undergone cardiac transplantation, compared with three of the 12 asymptomatic patients. CONCLUSION: In doxorubicin-treated long-term survivors of childhood cancer, enalapril-induced improvement in LV structure and function is transient. The primary defect, which is LV wall thinning, continues to deteriorate, and thus the short-term improvement was mostly related to lowered diastolic blood pressure.

Adolescent↗
PubMed2002

Cardiovascular status of infants and children of women infected with HIV-1 (P(2)C(2) HIV): a cohort study.

BACKGROUND: Data from cross-sectional and short-term longitudinal studies have suggested that children infected with HIV-1 might have cardiovascular abnormalities. We aimed to investigate this hypothesis in a long-term cohort study. METHODS: We measured cardiovascular function every 4-6 months for up to 5 years in a birth cohort of 600 infants born to women infected with HIV-1. We included 93 infants infected with HIV-1 and 463 uninfected infants (internal controls) from the same cohort. We also included a cross-sectionally measured comparison group of 195 healthy children born to mothers who were not infected with HIV-1 (external controls). FINDINGS: Children infected with HIV-1 had a significantly higher heart rate at all ages (mean difference 10 bpm, 95% CI 8-13) than internal controls. At birth, both cohort groups of children had similar low left ventricular (LV) fractional shortening. At 8 months, fractional shortening was similar in internal and external controls, whereas in children infected with HIV-1, fractional shortening remained significantly lower than in controls for the first 20 months of life (mean difference from internal controls at 8 months 3.7%, 2.3-5.1). LV mass was similar at birth in both cohort groups, but became significantly higher in children with HIV-1 from 4-30 months (mean difference 2.4 g at 8 months, 0.9-3.9). CONCLUSIONS: Vertically-transmitted HIV-1 infection is associated with persistent cardiovascular abnormalities identifiable shortly after birth. Irrespective of their HIV-1 status, infants born to women infected with HIV-1 have significantly worse cardiac function than other infants, suggesting that the uterine environment has an important role in postnatal cardiovascular abnormalities.

Cardiovascular Abnormalities↗
PubMed2002

Doxorubicin administration by continuous infusion is not cardioprotective: the Dana-Farber 91-01 Acute Lymphoblastic Leukemia protocol.

PURPOSE: Acute doxorubicin-induced cardiotoxicity can be prevented in adults by continuous infusion of the drug, but mechanisms of cardiotoxicity are different in children. We compared cardiac outcomes in children receiving bolus or continuous infusion of doxorubicin. PATIENTS AND METHODS: In a randomized study, children with high-risk acute lymphoblastic leukemia received doxorubicin 360 mg/m(2) in 30-mg/m(2) doses every 3 weeks either by bolus (within 1 hour, n = 57) or by continuous infusion (over 48 hours, n = 64). Echocardiograms obtained before doxorubicin and at longest follow-up times were centrally remeasured, and z scores of cardiac measurements were calculated based on a healthy population. RESULTS: The groups were similar in age, sex distribution, doxorubicin dose, and duration of follow-up. Before treatment, measures of left ventricular (LV) structure and function did not reveal dilated cardiomyopathy and were not statistically different between bolus and continuous-infusion groups. The follow-up echocardiograms demonstrated no significant difference between the two groups for any cardiac characteristic, but both groups showed significant abnormalities of LV structure and function compared with normal and with baseline. For example, the mean LV fractional shortening fell by approximately two SD in both groups between the two echocardiograms. LV contractility was depressed in both groups (for bolus patients, median z score = -0.70 SD, P =.006; for continuous-infusion patients, median z score = -0.765, P =.005). Dilated cardiomyopathy and inadequate LV hypertrophy were noted in both groups. Clinical cardiac manifestations and event-free survival did not differ. CONCLUSION: Continuous doxorubicin infusion over 48 hours for childhood leukemia did not offer a cardioprotective advantage over bolus infusion. Both regimens were associated with progressive subclinical cardiotoxicity. Other cardioprotective strategies should be explored.

Adolescent↗
PubMed2002

Systolic and diastolic performance late after the Fontan procedure for a single ventricle and comparison of those undergoing operation at <12 months of age and at >12 months of age.

To evaluate whether surgical history can influence systolic and diastolic properties of a functional single left ventricle after Fontan operation, we echocardiographically investigated 31 patients (mean age 93.7 months; range 21 to 276); 21 patients were >12 months of age (group A) and 10 were <12 months of age (group B) at the time of the Fontan and/or cavopulmonary procedure. In group A we found persistent abnormalities of left ventricular mass index (95.9 vs 64.1 g/m(2), p <0.05) at long-term follow-up, whereas group B had normal left ventricular mass (61.9 vs 64.1 g/m2, p = NS). In contrast, a diastolic pattern characterized by augmented late diastolic filling was present in both patient groups regardless of age at operation and length of follow-up (E/A in group A 1.3 +/- 0.4, E/A in group B 1.6 +/- 1.5, E/A in controls 1.7 +/- 0.6; A vs B, p = NS; A vs controls, p <0.05). We concluded that patients with a single left ventricle who undergo an unloading procedure performed within the first year of life have complete normalization of left ventricular mass, although a diastolic filling pattern suggestive of augmented compliance persists, regardless of the age at operation.

Adolescent↗
PubMed2002

Adaptive mechanisms of left ventricular diastolic function to the physiologic load of pregnancy.

BACKGROUND: Pregnancy is associated with marked alteration in cardiovascular hemodynamics. Recent reports have characterized the effects on cardiac systolic function. Little has been written on the influences of loading conditions on Doppler measures of diastolic function during pregnancy. HYPOTHESIS: Stage of pregnancy has an impact on Doppler indices of diastolic function independent of loading conditions, systolic function, and heart rate. METHOD: Thirty healthy women were prospectively evaluated by serial echocardiography and Doppler examinations at six time periods: 10-12, 18-20, 28-30, 36-38 weeks gestation, 2-4 and 12-14 weeks postpartum. The related effects on indices of diastolic function and its interaction with load, heart rate, mass, and systolic function were determined. RESULTS: Compared with the nonpregnant state, early (E) velocity increased (0.7+/-0.1-0.9+/-0.1 m/s, p = 0.0001), peaking at 18 weeks and returning to normal levels during late pregnancy. Atrial phase (A) velocity peaked at 18 weeks (0.48+/-0.12-0.60+/-0.13 m/s, p = 0.0001), remaining high throughout the rest of pregnancy. Consequently, the EWA ratio fell significantly during late pregnancy, from 1.9+/-0.4 to 1.4+/-0.3 (p = 0.02). In addition, mean acceleration was significantly increased in early pregnancy with a peak at 18 weeks (7.4+/-1.3 m/s2), returning to nonpregnant level at term (5.7+/-1.4 m/s2, p = 0.0001). Generalized estimating equation using multivariate regression analysis demonstrated that rising heart rate and stroke volume index had an independent effect on A velocity, and that contractility and preload had an independent effect on E velocity. Pregnancy itself had an independent influence on early filling, not explained by the other parameters. CONCLUSIONS: During normal pregnancy, there is a reversible shift in transmitral flow velocities from early to late filling with a decrease in acceleration, consistent with an increase in ventricular compliance. Changes in heart rate, preload, and contractility, as well as stage of pregnancy influence this alteration.

Adult↗
PubMed2002

Echocardiographic assessment of the right ventricular response to hypertension in neonates on the basis of average-shaped contraction models.

BACKGROUND AND METHOD: We evaluated a new method of shape analysis in defining right ventricle (RV) response to pressure overload. Twenty-five neonatal patients (13 with RV hypertension, 12 without) underwent echocardiographic imaging and reconstruction of RV regional chamber volumes over 1 cardiac cycle. Group tracing data in coronal, sagittal, and transverse echocardiography planes were then shape-averaged to construct normal- and hypertensive-average-shape contraction models. Each patient's RV was classified as more similar to the normal- or hypertensive-average-shape model on the basis of the median tangent-angle difference, a quantitative technique of shape comparison. RESULTS: Ejection fraction, time of end systole, and ejection rate demonstrated significant regional differences between normotensive and hypertensive contractions. The normal-average-shape contraction model correctly diagnosed all patients who were normotensive (specificity 100%) and the hypertensive-average-shape model identified 11 of 13 patients who were hypertensive (sensitivity 85%). CONCLUSION: Reconstructed-shape contraction models throughout 1 cardiac cycle identify altered patterns of RV contraction in the presence of pulmonary hypertension.

Echocardiography↗
PubMed2002

Incidence of cardiac abnormalities in children with human immunodeficiency virus infection: The prospective P2C2 HIV study.

OBJECTIVE: To describe the 5-year cumulative incidence of cardiac dysfunction in human immunodeficiency virus (HIV)-infected children. STUDY DESIGN: We used a prospective cohort design, enrolling children at 10 hospitals. Group I included 205 vertically HIV-infected children enrolled at a median age of 1.9 years. Group II consisted of 600 HIV-exposed children enrolled prenatally or as neonates, of whom 93 were ultimately HIV-infected. The main outcome measures were echocardiographic indexes of left ventricular dysfunction. RESULTS: In group I, the 5-year cumulative incidence of left ventricular fractional shortening </=25% was 28.0%. The 5-year incidence of left ventricular end-diastolic dilatation was 21.7%, and heart failure and/or the use of cardiac medications 28.8%. The mortality rate 1 year after the diagnosis of heart failure was 52.5% [95% CI, 30.5-74.5]. Within group II, the 5-year cumulative incidence of decreased fractional shortening was 10.7% in the HIV-infected compared with 3.1% in the HIV-uninfected children (P =.01). Left ventricular dilation, heart failure, and/or the use of cardiac medications were more common in infected compared with uninfected children. CONCLUSIONS: During 5 years of follow-up, cardiac dysfunction occurred in 18% to 39% of HIV-infected children and was associated with an increased risk of death. We recommend that HIV-infected children undergo routine echocardiographic surveillance for cardiac abnormalities.

Disease Progression↗
PubMed2002

Wall stress misrepresents afterload in children and young adults with abnormal left ventricular geometry.

Wall stress, although commonly used as an index of afterload, fails to take into account forces generated within the wall of the left ventricle (LV) that oppose systolic fiber shortening. Wall stress may, therefore, misrepresent fiber stress, the force resisting fiber shortening, particularly in the presence of an abnormal LV thickness-to-dimension ratio (h/D). M-mode LV echocardiograms were obtained from 207 patients with a wide range of values for LV mass and/or h/D. Diagnoses were valvar aortic stenosis, coarctation repair, anthracycline treated, and severe aortic and/or mitral regurgitation. End-systolic wall stress (WS(es)) and fiber stress (FS(es)) were expressed as age-corrected Z scores relative to a normal population. The difference between WS(es) and FS(es) was extreme when h/D was elevated or reduced [WS(es) Z score - FS(es) Z score = 0.14 x (h/D)(-1.47) - 2.13; r = 0.78, P < 0.001], with WS(es) underestimating FS(es) when h/D was increased and overestimating FS(es) when h/D was decreased. Analyses of myocardial mechanics based on wall stress have limited validity in patients with abnormal ventricular geometry.

Adolescent↗