Insulin resistance and arterial stiffness in healthy adolescents and young adults.

AIMS/HYPOTHESIS: Increased arterial stiffness is a risk factor for adverse cardiovascular events in adults with obesity-related insulin resistance (IR) or type 2 diabetes mellitus. Adolescents with type 2 diabetes have stiffer vessels. Whether stiffness is increased in obesity/IR in youth is not known. We sought to determine if IR was a determinant of arterial stiffness in youth, independent of obesity and cardiovascular risk factors. METHODS: We measured cardiovascular risk factors, IR, adipocytokines and arterial stiffness (brachial artery distensibility [BrachD], pulse wave velocity [PWV]) and wave reflection (augmentation index [AIx]) in 343 adolescents and young adults without type 2 diabetes (15-28 years old, 47% male, 48% non-white). Individuals <85th percentile of BMI were classified as lean (n = 232). Obese individuals were grouped by HOMA index as not insulin resistant (n = 46) or insulin resistant (n = 65) by the 90th percentile for HOMA for lean. Mean differences were evaluated by ANOVA. Multivariate models evaluated whether HOMA was an independent determinant of arterial stiffness. RESULTS: Risk factors deteriorated from lean to obese to obese/insulin resistant (all p ≤ 0.017). Higher AIx, lower BrachD and higher PWV indicated increased arterial stiffness in obese and obese/insulin-resistant participants. HOMA was not an independent determinant. Age, sex, BMI and BP were the most consistent determinants, with HDL-cholesterol playing a role for BrachD and leptin for PWV (AIx R²= 0.34; BrachD R² = 0.37; PWV R² = 0.40; all p ≤ 0.02). CONCLUSIONS/INTERPRETATION: Although IR is associated with increased arterial stiffness, traditional cardiovascular risk factors, especially obesity and BP, are the major determinants of arterial stiffness in healthy young people.

The effects of obesity and type 2 diabetes mellitus on cardiac structure and function in adolescents and young adults.

AIMS/HYPOTHESIS: We sought to evaluate the effects of obesity and obesity-related type 2 diabetes mellitus on cardiac geometry (remodelling) and systolic and diastolic function in adolescents and young adults. METHODS: Cardiac structure and function were compared by echocardiography in participants who were lean, obese or obese with type 2 diabetes (obese diabetic), in a cross sectional study. Group differences were assessed using ANOVA. Independent determinants of cardiac outcome measures were evaluated with general linear models. RESULTS: Adolescents with obesity and obesity-related type 2 diabetes were found to have abnormal cardiac geometry compared with lean controls (16% and 20% vs <1%, p < 0.05). These two groups also had increased systolic function. Diastolic function decreased from the lean to obese to obese diabetic groups with the lowest diastolic function observed in the obese diabetic group (p < 0.05). Regression analysis showed that group, BMI z score (BMIz), group × BMIz interaction and systolic BP z score (BPz) were significant determinants of cardiac structure, while group, BMIz, systolic BPz, age and fasting glucose were significant determinants of the diastolic function (all p < 0.05). CONCLUSIONS/INTERPRETATION: Adolescents with obesity and obesity-related type 2 diabetes demonstrate changes in cardiac geometry consistent with cardiac remodelling. These two groups also demonstrate decreased diastolic function compared with lean controls, with the greatest decrease observed in those with type 2 diabetes. Adults with diastolic dysfunction are known to be at increased risk of progressing to heart failure. Therefore, our findings suggest that adolescents with obesity-related type 2 diabetes may be at increased risk of progressing to early heart failure compared with their obese and lean counterparts.

Effect of veno-venous ultrafiltration on myocardial performance immediately after cardiac surgery in children. A prospective randomized study.

OBJECTIVES: This study sought to evaluate the effects of veno-venous ultrafiltration on myocardial contractility in children undergoing cardiopulmonary bypass (CPB) for repair of congenital heart defects. BACKGROUND: Ultrafiltration (UF) is currently used to diminish postoperative fluid accumulation following CPB in children. Previous reports indicate improvement in hemodynamics immediately after UF, but the mechanism of its action is unknown. METHODS: Twenty-three patients (ages 2 months to 9.1 years; 13 males, 10 females) underwent UF for 10 min after CPB. Twelve patients underwent UF immediately after CPB (Group A). They were studied: (1) before and (2) after CPB, (3) after UF, and (4) 10 min after UF. Eleven patients underwent UF 10 min after CPB (Group B). They were studied: (1) before and (2) after CPB, (3) after a 10-min delay before UF, and (4) after UF. Contractility was determined by the difference in the observed and predicted velocity of circumferential fiber shortening for the measured wall stress, using transesophageal echocardiography. Left ventricular wall thickness was also measured. RESULTS: There was significant improvement in contractility after UF in both groups (mean+/-SD, Group A: -0.28+/-0.13 to -0.01+/-0.21 circ/s, p < 0.05; Group B: -0.26+/-0.16 to -0.11+/-0.17 circ/s, p < 0.05). Myocardial thickness to cavity dimension decreased in both groups following UF (Group A: 0.19+/-0.04 to 0.14+/-0.03, p < 0.05; Group B: 0.18+/-0.04 to 0.14+/-0.03, p < 0.05). CONCLUSIONS: UF improves hemodynamics by improving contractility and possibly by reducing myocardial edema in children following cardiac surgery. Enhanced patient outcome after ultrafiltration may in part be due to these changes.

Frequency and significance of left ventricular thickening in transplanted hearts in children.

The pediatric myocardium has been shown to thicken markedly during steroid administration for the treatment of pulmonary or neurologic disease. Yet, in the pediatric heart transplant patient, left ventricular (LV) thickening is sometimes used as a marker for rejection without accounting for steroid immunosuppression. The aim of this study was to determine timing and correlates of changes in LV thickness in pediatric cardiac transplant patients. In 11 patients (11 days old to 16 years old), LV thickness (mass) was first measured during the entire post-transplant course. Second, thickness was measured before and during rejection. Last, to separate the independent effects of rejection and steroids on LV mass, echocardiograms were reviewed in the immediate post-transplant period, when our protocol prescribes dramatic changes in steroid doses and rejection episodes were rare. Specifically, the donor heart underwent 5 evaluations: at donation, at peak steroid dose, 5 days after peak steroid dose, at moderate steroid dose, and at very low maintenance dose. LV mass changed most dramatically and consistently during the first 20 to 40 days after transplant. Thereafter, mass had little consistent changes and did not change significantly during any of the 52 rejection episodes. Mass increased 5 days after peak steroid dose (54 +/- 30 to 74 +/- 38 g/ht2.7, p < 0.05) and decreased during low maintenance levels of steroids. Thickening was associated with cumulative steroid dose (r = 0.66, p = 0.03) and age (r = -0.62, p = 0.04). Thus, in pediatric heart transplant patients, as in other pediatric diseases, LV thickening is associated with steroid administration. Thickening may be an unreliable marker for acute cellular rejection.

Sialyl lewis oligosaccharide preserves cardiopulmonary and endothelial function after hypothermic circulatory arrest in lambs.

OBJECTIVE: Neutrophil adhesion to endothelium contributes to cardiopulmonary dysfunction after cardiac surgical procedures. Initial neutrophil-endothelial interactions involve selectins, which bind carbohydrate ligands, such as sialyl-Lewis(X). Blockade of selectin-mediated neutrophil interactions with CY1503, a synthetic oligosaccharide analog of sialyl-Lewis(X), could limit neutrophil-mediated injury after cardiopulmonary bypass. METHODS: The efficacy of CY1503 treatment was tested in a lamb model of cardiopulmonary bypass with hypothermic circulatory arrest. Neonatal lambs received CY1503 (n = 6, CPB-CY1503) or saline solution vehicle (n = 7, CPB-saline) into the pump prime before bypass and as a continuous infusion throughout reperfusion. Five lambs served as control animals for in vitro microvessel studies. Indexes of myocardial function (preload recruitable stroke work index, and rate of pressure rise) and pulmonary function (compliance, airway resistance, and arterial PO (2)) were measured before bypass and during reperfusion. The effect of CY1503 on endothelium-dependent vascular reactivity was assessed by means of in vitro pulmonary and coronary microvessel studies. RESULTS: Myocardial function was depressed after circulatory arrest, but CY1503 preserved function near baseline (36% +/- 25% vs 99% +/- 19% of baseline at 3 hours of reperfusion). CY1503-treated animals also demonstrated improved pulmonary function during reperfusion. In vitro microvessel analysis of vascular reactivity revealed endothelial dysfunction after circulatory arrest compared with control lambs. CY1503-treated lambs (CPB-CY1503) had intact endothelial function, as demonstrated by normal vasodilatory responses to endothelium-dependent vasodilators. CONCLUSIONS: CY1503 preserves cardiopulmonary and endothelial function after cardiopulmonary bypass and hypothermic circulatory arrest in neonatal lambs. This suggests a role for selectin-mediated, neutrophil-endothelial interactions in the inflammatory response after cardiac operations.

Obesity and high-density lipoprotein cholesterol in black and white 9- and 10-year-old girls: The National Heart, Lung, and Blood Institute Growth and Health Study.

It has been hypothesized that the role of obesity in the pathogenesis of coronary heart disease (CHD) may be mediated in part through its inverse relationship with high-density lipoprotein cholesterol (HDL-C). Obesity is inversely correlated with HDL-C, and HDL-C has been shown to be protective against CHD. Defining obesity as excess weight due to excess fat, the purpose of this analysis was to determine whether the effects of obesity are due to increased weight or to increased adiposity. Using baseline lipid and anthropometric data from the National Heart, Lung, and Blood Institute Growth and Health Study, cross-sectional associations among body mass, adiposity, HDL-C, and related lipid parameters (apolipoprotein [apo] AI and triglycerides [TGs]) were assessed in 821 white and 763 black 9- and 10-year-old girls, using multivariate linear regression models. Equations predicting HDL-C, apo AI, and TGs from age, race, race, sexual maturation stage, adiposity (sum of truncal--subscapular and suprailiac--skinfolds), and ponderosity (a ratio of weight to height) revealed that adiposity, not ponderosity, was the significant body composition variable to explain the variability of each of the lipids assessed. The amount of variance explained in each of the models was small (R2

Automated echocardiographic analysis of systemic ventricular performance in hypoplastic left heart syndrome.

In patients with hypoplastic left heart syndrome, the right ventricle is positioned as the systemic ventricle. Monitoring its function is important but difficult because of its unusual position and geometry. The purposes of this study were to determine the feasibility of applying automatic echocardiographic measurements to the evaluation of right ventricular function in patients with hypoplastic left heart syndrome and to compare their function with that of normal subjects. Eleven patients with hypoplastic left heart syndrome (mean age 1.6 years) were evaluated with automatic border detection. Images were adequate if greater than 85% of the endocardium was being tracked. Systolic indexes were fractional area change and peak emptying rate; diastolic indexes were peak filling rate and the proportion of filling that occurred during rapid filling, diastasis, and atrial contraction. These data were compared with those in 18 normal control subjects. Three patients had completed stage 1 (aortic reconstruction, surgical shunt, and atrial septectomy), three patients had completed stage 2 (hemi-Fontan), and five patients had completed stage 3 (Fontan). Images were adequate in all cases. Fractional area change and peak emptying rate were significantly lower in the patients with hypoplastic left heart syndrome compared with control subjects (38% +/- 6% versus 61% +/- 10% and 3.5 +/- 0.9 versus 5.3 +/- 1.3 sec-1, respectively). Peak filling rate was significantly lower (4.1 +/- 1.3 versus 6.6 +/- 2.3 sec-1) and atrial contribution was significantly higher (18% +/- 7% versus 12% +/- 4%) in the patients. Automated echocardiographic analysis is feasible in assessing systemic ventricular function in children with hypoplastic left heart syndrome. These patients have abnormal systolic and diastolic function. Automatic border detection may be useful in detecting and monitoring systemic ventricular dysfunction as these patients progress through the surgical stages of repair.

Noninvasive markers for acute heart transplant rejection in children with the use of automatic border detection.

A noninvasive method to detect heart transplant rejection would allow for increased monitoring at reduced risk. Automatic border detection is a new method to assess diastolic abnormalities. The purpose of this study was to determine whether automatic border detection of left ventricular filling detects rejection in children. Nineteen episodes of biopsy-proven rejection in 10 children were retrospectively reviewed. Echocardiograms during rejection were compared with those before rejection and during recovery. Automatic border detection indices were percentage of total left ventricular filling as a result of rapid filling, diastasis, and atrial contraction. The percentage of total ventricular filling during diastasis increased significantly during rejection (10% +/- 6% versus 15% +/- 8%, p = 0.02), and the percentage of filling during the rapid filling phase decreased during rejection (82% +/- 8% versus 77% +/- 11%, p = 0.08). These changes were even more marked for the most severe episodes of rejection. These changes resolved at recovery. Automatic border detection of left ventricular filling patterns are altered during cardiac rejection in children. Filling during diastasis increases significantly, and filling during the rapid filling phase decreases. A prospective analysis is needed to determine whether these changes in filling can obviate the need for cardiac biopsy.

Pulmonary venous flow Doppler velocities in children.

We report the results of a prospective study of pulmonary venous (PV) flow Doppler velocities in 68 normal children. We sought to establish the normal PV flow velocities in the broad pediatric population, compare these velocities to heart rate and age. In normal children, there is a wide range of PV flow velocities, most of which correlate with age and heart rate. However, the PV flow velocities and their durations do not distinguish the age groups. The peak velocity of systolic forward flow and atrial reversal flow in the pulmonary vein were independent of heart rate. The PV flow peak systolic velocity showed a weak correlation with the velocity of the mitral inflow early wave. However, the velocity of atrial reversal flow showed no correlation with the mitral inflow A velocity (late wave), which is generated by the same force of atrial contraction.

The role of automatic endocardial edge detection in the evaluation of left ventricular diastolic function in children.

Forty-nine normal children underwent echocardiography to study the role of automatic border detection (ABD) in diastolic evaluation by (1) determining the relationship of diastolic ABD indexes to heart rate and traditional diastolic indexes and (2) establishing inter-observer variability. ABD diastolic indexes were less associated with heart rate than were M-mode and Doppler diastolic indexes. ABD left ventricular peak filling rate correlated with Doppler mitral E wave peak velocity. Interobserver variability for ABD indexes ranged from 4% to 24%. We then compared the ability of ABD left ventricular filling rate to M-mode and Doppler indexes to detect diastolic dysfunction in a test group of 20 children with diastolic disease. ABD left ventricular peak filling rate had the highest sensitivity of all indexes (90%). Thus ABD left ventricular peak filling rate is an accurate index of diastolic function that is readily usable by almost all clinical laboratories.

Diastolic dysfunction in young patients with insulin-dependent diabetes mellitus as determined by automated border detection.

Diastolic dysfunction is an early harbinger for systolic dysfunction in insulin-dependent diabetes mellitus (IDDM). To determine the role of automated border detection (ABD) in detecting diastolic abnormalities and whether IDDM control correlates with abnormalities, 21 young IDDM patients (22 +/- 4 years old) and 19 control subjects underwent echocardiography. ABD indices included the percent contribution to total left ventricular filling of the three phases of diastole (rapid filling, diastasis, and atrial contraction) and peak filling rate. Doppler indices included E/A ratio and peak filling rate. Rapid filling phase was lower in the IDDM patients compared with control subjects (73% +/- 5% versus 80% +/- 5%, p = 0.0006), and atrial contraction filling was higher (19% +/- 4% versus 14% +/- 3%, p = 0.0003). Doppler indexes showed similar changes. Glycosylated hemoglobin, insulin dosage, and duration of IDDM since puberty were associated with filling abnormalities. Young patients with IDDM have increased atrial contraction and reduced rapid filling phases detected by automatic border detection, and these diastolic abnormalities are related to the diabetic disease process.

Surveying graduates of combined internal medicine-pediatrics residency programs.

Graduates of all U.S. combined internal medicine-pediatrics residency programs were surveyed in 1987 regarding a variety of demographic information about their residencies and current practices, the residency curricula they had followed for both specialties, and recommendations for modifications in training. The 71 responding graduates (from a total of 112) reported patient care as their major involvement (mean of 42.9 hours per week), with a majority (83%) seeing patients in both pediatric and adult age groups. Most were involved in primary care only (64%). The graduates reported that during both pediatrics and internal medicine training, they had had too many inpatient and intensive care rotations and too few elective and ambulatory rotations. The most important subspecialty rotations in internal medicine were considered to be cardiology, dermatology, and pulmonary medicine; and in pediatrics, infectious disease, cardiology, and adolescent medicine. The graduates recommended more outpatient subspecialty rotations, ambulatory rotations in medicine and pediatrics, and a combined medicine-pediatrics continuity clinic.

Consequences of smoking and caffeine consumption during pregnancy in women with type 1 diabetes.

OBJECTIVE: To test the hypothesis that, in women with type 1 diabetes, prenatal smoking and caffeine consumption during pregnancy are associated with an increased risk of adverse maternal and perinatal outcomes. METHODS: A secondary analysis of data on pregnant women with type 1 diabetes from an interdisciplinary program of Diabetes in Pregnancy. Women were interviewed monthly, by a trained non-medical member of the research team, using a standardized questionnaire, to ascertain daily smoking habits and caffeine consumption. RESULTS: Smoking and caffeine information were available on 191 pregnancies, 168 progressing beyond 20 weeks of gestation. Early pregnancy smoking (OR 3.3, 95% CI 1.2, 8.7) and caffeine consumption (OR 4.5, 95% CI 1.2, 16.8) were associated with increased risk of spontaneous abortion when controlling for age, years since diagnosis of diabetes, previous spontaneous abortion, nephropathy and retinopathy. Smoking throughout pregnancy was significantly associated with decreased birth weight and prolonged neonatal hospital stay. Smoking throughout pregnancy (OR 0.2, 95% 0.1, 1.0) and caffeine consumption after 20 weeks (OR 0.3, 95% CI 0.1, 1.0) were associated with reduced risk of pre-eclampsia. CONCLUSIONS: Caffeine consumption during early pregnancy, regardless of glycemic control, increases the risk of spontaneous abortion. Smoking throughout pregnancy and caffeine consumption are associated with reduced risk of pre-eclampsia.

Two-dimensional echocardiographic valve measurements in healthy children: gender-specific differences.

The goal of this study was to create nomograms of echocardiographic two-dimensional valve dimensions based on a large group of children without heart disease. Children aged 0-18 years underwent standard echocardiographic evaluation. Referring diagnoses were chest pain, heart murmur, or syncope. Only patients with a structurally normal heart and normal systolic and diastolic function were included. All four valves were measured at their maximal dimensions. A total of 748 children (314 girls and 434 boys) met the inclusion criteria. Mean values and standard deviations were calculated, and z value nomograms based on body surface area were developed. Surprisingly, the boys had larger valve dimensions at all ages. These valve dimension differences were statistically significant for three of four valves even after adjustment for the differences in body sizes. The difference may be due to higher circulating blood volume in boys compared to that in girls. Because the differences are subtle, they reach statistical significance only when evaluated in a large group of subjects. Presented normal value data will be helpful in following cardiology patients and evaluating intervention strategy in patients with valve hypoplasia.

Steroid therapy and cardiac function in Duchenne muscular dystrophy.

Duchenne muscular dystrophy leads to progressive deterioration in skeletal and cardiac muscle function. Steroids prolong ambulation and improve respiratory muscle strength. The authors hypothesized that steroid treatment would stabilize cardiac muscle function. Echocardiograms performed from 1997 to 2004 for 111 subjects 21 years of age or younger with Duchenne muscular dystrophy were restrospectively reviewed. The medical record was reviewed for steroid treatment. Untreated and steroids-treated subjects did not differ in age, height, weight, body mass index, systolic and diastolic blood pressure, or left ventricular mass. The shortening fraction was lower in the untreated group. Of those treated, 29 received prednisone and 19 received deflazacort. There was no difference in the shortening fraction between the two treated subgroups. Treated subjects not receiving steroids still had a normal shortening fraction, which was no different from the shortening fraction of those still receiving treatment. As compared with the treated subjects, the untreated subjects 10 years of age or younger were 4.4 times more likely to have a shortening fraction less than< 28% (p = 0.03), and the untreated subjects older than 10 years were 15.2 times more likely to have a shortening fraction less than< 28% (p < 0.01). This retrospective study suggests that the progressive decline in cardiac function of patients with Duchenne muscular dystrophy can be altered by steroid treatment. The effect appears to be sustained beyond the duration of treatment and independent of steroid type.

The utility of body mass index as a measure of body fatness in children and adolescents: differences by race and gender.

OBJECTIVE: To evaluate whether body mass index (BMI) is a representative equivalent measure of body fatness independent of age, race, gender, sexual maturation, and distribution of fat in children and adolescents. STUDY DESIGN: Cross-sectional study of 192 healthy subjects (100 boys and 92 girls, 103 white and 89 black) age 7 to 17 years. Methods. Height and weight were measured in the standard fashion, and BMI (kg/m) was calculated from these values. Fat mass and percent body fat were determined using dual-energy x-ray absorptiometry. Sexual maturation was evaluated by physical assessment. Distribution of fat was determined by the waist:hip ratio. RESULTS: There were no significant differences by gender and ethnic group for any of the demographic or anthropometric variables, except waist:hip ratio, which was higher in white compared with black boys. BMI was significantly and positively correlated with age, stage of maturation, and all of the anthropometric variables in each race-sex group. The correlation of maturation stage with BMI was stronger than the correlation between age and BMI. A multiple regression analysis showed that BMI, gender, race, sexual maturation, and distribution of fat were all significant independent correlates of the percent body fat (multiple R = .77). The percent body fat-BMI relationship was dependent on the stage of sexual maturation, gender (for an equivalent BMI, girls have greater amounts of body fat than boys), race (for equivalent BMI, whites have higher body fat than blacks), and waist:hip ratio (for equivalent BMI, those with central obesity have greater body fatness than those with peripheral obesity). CONCLUSION: BMI is not an equivalent measure of the percent body fat for each race-sex group. When BMI is used as a measure of body fatness in a research or clinical setting, particularly when comparisons are made across race and gender, it may be important to consider the maturation stage, race, gender, and distribution of body fat in the interpretation of the results.

Utility of different measures of body fat distribution in children and adolescents.

The distribution of body fat has been shown to be an important determinant of cardiovascular disease risk. The purpose of this study was to evaluate which method of evaluating body fat distribution compares most favorably with dual-energy x-ray absorptiometry. The study included 201 children and adolescents aged 7-17 years who were recruited from Cincinnati, Ohio, schools in 1992-1993. The strongest correlate of fat distribution was waist circumference (r = 0.80). Age was a more important determinant of fat distribution than was pubertal maturation. There was a greater relative deposition of central body fat with increasing age. Multiple regression analysis demonstrated that waist circumference was the best simple measure of fat distribution, since it was least affected by gender, race, and overall adiposity. Waist circumference is easy to determine and is a useful measure of fat distribution for children and adolescents.

Mother-daughter correlations of obesity and cardiovascular disease risk factors in black and white households: the NHLBI Growth and Health Study.

OBJECTIVES: This study sought to evaluate obesity as a potential explanatory factor for the increased relative risk for cardiovascular disease in Black compared with White women. METHODS: Familial associations for obesity and cardiovascular disease risk factors were assessed in 720 White and 580 Black mother-daughter pairs from the National Heart, Lung, and Blood Institute's Growth and Health Study by using Pearson's chi square, Spearman's correlations, and partial correlations. RESULTS: Black girls and mothers were significantly heavier and had higher body mass indices than their White counterparts. In each racial group, significant, positive mother-daughter correlations existed for weight, body mass index, and triceps skinfolds, and for all cardiovascular disease risk factors. Obesity measures correlated positively with systolic blood pressure and triglycerides and inversely with high-density lipoprotein cholesterol in girls and mothers of both races. Correlations between mothers and daughters for exercise and ideal body shape were weak and did not explain obesity associations. CONCLUSIONS: Intrafamilial associations of obesity, cardiovascular disease risk factors, and the obesity-cardiovascular disease risk factor relationship support the position that increased cardiovascular disease morbidity and mortality rates in Black women may be linked to excess obesity in Black women compared with White ones.

Echocardiographic determination of left ventricular preload, afterload, and contractility during and after exercise.

Left ventricular (LV) performance increases during acute exercise, but the mechanisms for this increase are not known. To determine the feasibility of studying echocardiographic indexes of performance and its determinants (preload, afterload, and contractility) during exercise, and to examine changes in these indexes, we tested 24 normal male subjects (aged 21 +/- 5 years) by echocardiography--at rest; at 25%, 50%, 75%, and 100% maximal oxygen consumption; and immediately, 3 minutes, and 5 minutes after cycle ergometry. The LV performance (shortening fraction), preload (LV end-diastolic dimension), afterload (wall stress), contractility, heart rate, and peak systolic blood pressure were measured. Data could be obtained during 98% of the exercise studies. The LV performance, heart rate, blood pressure, and contractility increased significantly with increasing exercise, reaching peak levels at maximal exercise, and decreased toward resting levels in the post-exercise period. The LV afterload and preload decreased significantly with increasing exercise intensity, reaching nadir levels at maximal exercise, and increased toward resting levels in the post-exercise period. We conclude that echocardiographic measurement of LV performance and its determinants is feasible during exercise. Performance of the LV increases with increasing exercise intensity because of an associated increase in contractility and decrease in afterload. These data will serve as a basis for comparison with those from other patient populations.