Biomedical subjects

Dalane W Kitzman

Publications and source records attributed to Dalane W Kitzman.

At least 37 records · Page 2Linked to original sources

PubMed2005

Body composition and fat distribution influence systemic hemodynamics in the absence of obesity: the HyperGEN Study.

BACKGROUND: We have shown that increased cardiac output is related to both fat-free mass and fat mass in obesity. OBJECTIVE: We studied the association of body fat distribution and body composition with flow-resistance relations in overweight. DESIGN: We studied 521 overweight, nonobese participants in the Hypertension Genetic Epidemiology Network (HyperGEN) Study-a component of the National Heart, Lung, and Blood Institute Family Blood Pressure Program, designed to assess the genetic basis of hypertension. Participants had normal ventricular function and no cardiovascular disease: 261 with central fat distribution (CFD) (waist girth >88 cm in women and >102 cm in men) and 260 with peripheral fat distribution (PFD). Fat-free mass (FFM) and fat mass (FM) were measured by bioelectric impedance. Body composition was estimated as FM/FFM. Echocardiographic stroke volume (SV) and cardiac output (CO) were measured. RESULTS: Hypertension was present in 73% of the subjects with PFD and in 78% with CFD. Overweight with CFD was associated with greater FM/FFM in both normotensive and hypertensive participants. After FFM, age, sex, and race were controlled for, SV and CO were higher in subjects overweight with CFD than in those with PFD, whereas peripheral resistance was not significantly different. Differences in CO between CFD and PFD were reduced after further adjustment for FM. After the covariates were controlled for, hypertensive subjects had higher peripheral resistance and lower arterial compliance than did normotensive participants, but cardiac output was not significantly different. CONCLUSION: CFD is associated with more severe abnormalities in body composition and with higher CO independently of FFM in overweight, nonobese subjects.

Adipose Tissue↗

PubMed2005

Aortic valve sclerosis is associated with preclinical cardiovascular disease in hypertensive adults: the Hypertension Genetic Epidemiology Network study.

RATIONALE: Aortic valve sclerosis (AVS) has been associated with atherosclerosis and increased all-cause and cardiovascular death. However, whether AVS is associated with preclinical cardiovascular disease among adults at high risk because of hypertension has not been determined in a population-based sample. METHODS AND RESULTS: Clinical and echocardiographic parameters were measured in 1624 hypertensive participants (54 +/- 11 years, 65% women, 63% black, 17% diabetic, 19% smokers) without significant valvular or cardiovascular diseases in the population-based Hypertension Genetic Epidemiology Network study. The 152 participants with AVS (9.4%), compared with participants without AVS, were older, more often white, male, treated for hypertension or hypercholesteromia (all P < 0.05) and had longer duration and worse hypertension, but did not differ in diabetes status, smoking or fenfluramine use. Adjusting for age, gender and race, the AVS group had higher total cholesterol/high-density lipoprotein-cholesterol (P < 0.05). Controlling for age, gender, race and other clinical covariates, AVS was independently associated with higher septal, posterior and relative wall thicknesses, isovolumic relaxation time and left atrial diameter, and with mild aortic regurgitation and mitral annular calcification (all P < 0.05). CONCLUSIONS: In a population-based sample of hypertensive adults, AVS was prevalent (9.4%) and associated with a proatherogenic clinical profile and abnormal left ventricular geometry and filling, increased left atrial size and mitral annular calcification, which may contribute to the adverse prognosis associated with AVS.

Adult↗

PubMed2004

Left ventricular concentric geometry is associated with impaired relaxation in hypertension: the HyperGEN study.

AIMS: We tested the hypothesis that abnormal left ventricular (LV) relaxation is associated with concentric LV geometry. METHODS AND RESULTS: Doppler LV filling properties were studied in 1384 hypertensive participants without cardiovascular disease, from the HyperGEN population (731 women, 784 obese, 236 diabetic) and compared in four LV geometry groups; normal, concentric remodelling (3.5%), eccentric (23%), and concentric LV hypertrophy (4%), based on echocardiographic LV mass index (in g/m(2.7)). Abnormal LV relaxation was identified by European Society of Cardiology criteria in 275 subjects (20%). After accounting for significant confounders, E/A ratio and isovolumic relaxation time were not related to the presence of LV hypertrophy, but indicated abnormal relaxation when LV geometry was concentric (both P<0.0001). Deceleration time of E velocity was prolonged with LV hypertrophy (P<0.03), but the behaviour in relation to concentric LV geometry differed in the presence (prolonged) or absence (reduced) of LV hypertrophy (P=0.05), a difference independently related to the magnitude of both transmitral gradients and stroke volume (all P<0.05). Logistic regression showed that, compared with normal LV geometry, the odds of abnormal LV relaxation was 2.3-fold greater when LV geometry was concentric and that LV hypertrophy conferred a borderline higher risk than normal LV mass. CONCLUSIONS: In hypertensive individuals without prevalent cardiovascular disease from a multi-ethnic population-based sample, delayed LV relaxation is independently associated with concentric LV geometry.

Blood Flow Velocity↗

PubMed2004

Survival associated with two sets of diagnostic criteria for congestive heart failure.

Congestive heart failure (CHF) definitions vary across epidemiologic studies. The Framingham Heart Study criteria include CHF signs and symptoms assessed by a physician panel. In the Cardiovascular Health Study, a committee of physicians adjudicated CHF diagnoses, confirmed by signs, symptoms, clinical tests, and/or medical therapy. The authors used data from the Cardiovascular Health Study, a population-based cohort study of 5,888 elderly US adults, to compare CHF incidence and survival patterns following onset of CHF as defined by Framingham and/or Cardiovascular Health Study criteria. They constructed an inception cohort of nonfatal, hospitalized CHF patients. Of 875 participants who had qualifying CHF hospitalizations between 1989 and 2000, 54% experienced a first CHF event that fulfilled both sets of diagnostic criteria (concordant), 31% fulfilled only the Framingham criteria (Framingham only), and 15% fulfilled only the Cardiovascular Health Study criteria (Cardiovascular Health Study only). No significant survival difference was found between the Framingham-only group (hazard ratio = 0.87, 95% confidence interval: 0.71, 1.07) or the Cardiovascular Health Study-only group (hazard ratio = 0.89, 95% confidence interval: 0.68, 1.15) and the concordant group (referent). Compared with Cardiovascular Health Study central adjudication, Framingham criteria for CHF identified a larger group of participants with incident CHF, but all-cause mortality rates were similar across these diagnostic classifications.

Aged↗

PubMed2004

Increased left ventricular mass is a risk factor for the development of a depressed left ventricular ejection fraction within five years: the Cardiovascular Health Study.

OBJECTIVES: Our aim in this study was to determine whether increased left ventricular mass (LVM) is a risk factor for the development of a reduced left ventricular ejection fraction (LVEF). BACKGROUND: Prior studies have shown that increased LVM is a risk factor for heart failure but not whether it is a risk factor for a low LVEF. METHODS: As part of the Cardiovascular Health Study, a prospective population-based longitudinal study, we performed echocardiograms upon participant enrollment and again at follow-up of 4.9 +/- 0.14 years. In the present analysis, we identified 3,042 participants who had at baseline a normal LVEF and an assessment of LVM (either by electrocardiogram or echocardiogram), and at follow-up a measurable LVEF. The frequency of the development of a qualitatively depressed LVEF on two-dimensional echocardiography, corresponding approximately to an LVEF <55%, was analyzed by quartiles of baseline LVM. Multivariable regression determined whether LVM was independently associated with the development of depressed LVEF. RESULTS: Baseline quartile of echocardiographic LVM indexed to body surface area was associated with development of a depressed LVEF (4.8% in quartile 1, 4.4% in quartile 2, 7.5% in quartile 3, and 14.1% in quartile 4 [p < 0.001]). A similar relationship was seen in the subgroup of participants without myocardial infarction (p < 0.001). In multivariable regression that adjusted for confounders, both baseline echocardiographic (p < 0.001) and electrocardiographic (p < 0.001) LVM remained associated with development of depressed LVEF. CONCLUSIONS: Increased LVM as assessed by electrocardiography or echocardiography is an independent risk factor for the development of depressed LVEF.

Aged↗

PubMed2004

Differences in left ventricular structure between black and white hypertensive adults: the Hypertension Genetic Epidemiology Network study.

The degree to which ethnic differences in left ventricular structure among hypertensive adults are independent of clinical and hemodynamic factors remains uncertain. We assessed whether left ventricular mass and geometry differ between black and white hypertensives after accounting for differences in such factors. Our study group comprised 1060 black and 580 white hypertensive participants free of valvular or coronary disease in a population-based cohort. Blood pressure was measured during a clinic visit and echocardiography was performed using standardized protocols. After controlling for clinical and hemodynamic parameters (cardiac index, peripheral resistance index, and pulse pressure/stroke index), both left ventricular mass and relative wall thickness were higher in blacks than whites (173.9+/-30.9 versus 168.3+/-24.3 grams, P=0.006, and 0.355+/-0.055 versus 0.340+/-0.055 grams, P<0.001). Similarly, the adjusted risk of having left ventricular hypertrophy, whether indexed by height(2.7) or by body surface area, was greater for blacks than for whites (odds ratio: 1.80; 95% CI: 1.29 to 2.51; and odds ratio: 2.50; 95% CI: 1.58 to 3.96, respectively), and this was also true for concentric geometry (odds ratio: 2.28; 95% CI: 1.22 to 4.25). Further adjustment for relatedness in this genetic epidemiological study did not attenuate these differences. Our findings confirm the strong association between black ethnicity and increased left ventricular mass and relative wall thickness in hypertensive adults and demonstrate that these differences are independent of standard clinical and hemodynamic parameters. Whether such differences relate to distinct ambulatory pressure profiles or an ethnic propensity to cardiac hypertrophy requires further investigation.

Adult↗

PubMed2004

Association of inappropriate left ventricular mass with systolic and diastolic dysfunction: the HyperGEN study.

BACKGROUND: Left ventricular mass (LVM) exceeding values appropriate for individual workload is associated with concentric LV geometry and systolic dysfunction at both the midwall and chamber levels, even independently of clearcut LV hypertrophy, and is a marker of adverse prognosis. No information is available on whether inappropriate LVM is associated with alterations of LV diastolic properties in unselected population-based studies. METHODS: We examined 1513 hypertensive participants from the HyperGEN population who were without prevalent cardiovascular disease. The LVM prediction from stroke work (systolic blood pressure x Doppler stroke volume), sex, and height (in meters2.7) was derived in 210 nonobese, normal individuals. Observed/predicted LVM >133% defined inappropriate LVM. RESULTS: Participants with inappropriate LVM (229 subjects [15%]) exhibited higher LV dimensions and relative wall thickness, lower ejection fraction, midwall shortening and cardiac output, and prolonged isovolumic relaxation time (IVRT; P < or = .001). Other diastolic abnormalities were not associated with inappropriate LVM. After accounting for demographic and hemodynamic confounders, IVRT was directly related to excess LVM, whereas deceleration time of E velocity was negatively related to excess LVM. Nonechocardiographic correlates of prolonged relaxation included aging, African American ethnicity, male gender, and diabetes. CONCLUSIONS: The LVM exceeding the compensatory needs for workload is associated with delayed LV relaxation as well as mild midwall and chamber systolic dysfunction, independently of demographic, clinical, and hemodynamic confounders. Inappropriately high LVM also correlates with features of increased myocardial stiffness, coexisting with evidence of prolonged LV relaxation.

Adult↗

PubMed2004

Limited utility of the subcostal view for the echocardiographic evaluation of left ventricular mass in epidemiological studies of older persons.

BACKGROUND: Epidemiological estimates of left ventricular mass are based on echocardiographic imaging from the parasternal view, which is often unavailable in subjects with obesity or lung disease. This study was undertaken to assess whether the subcostal view is a valid alternative to estimate left ventricular mass in an unselected older population. METHODS: In a cross-sectional study of all the residents in Dicomano, Italy, aged > or =65 years, echocardiography was performed with a systematic attempt to obtain both the parastermal and the subcostal views. RESULTS: The parasternal view was missing in 73/614 participants, 48 of whom were imaged from the subcostal view. In participants imaged from both views, the subcostal view underestimated left ventricular cavity dimension and, consequently, left ventricular mass [79.7 (1.3) vs. 93.3 (1.5) g/m2; p<0.001]. Furthermore, the subcostal view was only 25% sensitive for the diagnosis of hypertrophy. Several multivariate regression models, developed in an equation development subgroup and tested in a validation subgroup, failed to correct the prediction of left ventricular mass based on measures taken from the subcostal view, also after inclusion of demographic, anthropometric, and spirometric covariates. CONCLUSIONS: In unselected older persons, the subcostal view does not improve the accuracy of echocardiographic estimation of left ventricular mass, which remains biased in epidemiological studies.

Echocardiography↗

PubMed2004

Effect of candesartan and verapamil on exercise tolerance in diastolic dysfunction.

Diastolic dysfunction may be exacerbated by increased systolic blood pressure (SBP) during exercise. Ang II may contribute to this process. We performed a randomized, double-blind, crossover study of two weeks of candesartan (16 mg) and verapamil (SR 160 mg). The 21 subjects were 64 +/- 10 years old with ejection fraction greater than 50%, no ischemia, mitral flow velocity E/A less than 1, normal resting SBP (< 150 mm Hg), and SBP greater than 200 mm Hg during exercise. Exercise tolerance was assessed using a Modified Bruce Protocol at baseline and after each two-week treatment period, separated by a two-week washout period. Quality of life (QOL) was assessed using the Minnesota Living with Heart Failure questionnaire. During exercise, Ang II levels increased from 29 +/- 18 to 33 +/- 18 pg/ml (P < 0.05). SBP during exercise was 213 +/- 9 mm Hg at baseline and similarly reduced by candesartan (198 +/- 18, P < 0.01) and verapamil (197 +/- 14, P < 0.01). With candesartan, exercise time increased from 793 +/- 182 seconds to 845 +/- 163 seconds (P < 0.05), and QOL improved from 11 +/- 14 to 5 +/- 6 (P < 0.05). In contrast, verapamil did not significantly improve exercise time or QOL. In patients with mild diastolic dysfunction at rest and a hypertensive response to exercise, both Ang II receptor blockade and verapamil blunted the hypertensive response to exercise. Ang II blockade increased exercise tolerance and improved QOL.

Antihypertensive Agents↗

PubMed2003

Associations of aortic and mitral regurgitation with body composition and myocardial energy expenditure in adults with hypertension: the Hypertension Genetic Epidemiology Network study.

BACKGROUND: It has been reported that aortic regurgitation, mitral valve regurgitation, or both are associated with lower body mass index, an index of body adiposity. However, the relations of valvular regurgitation to body composition and myocardial bioenergetic expenditure have not been previously investigated in a population-based sample. METHODS: We selected 1496 patients with hypertension who did not have diabetes mellitus to participate in the Hypertension Genetic Epidemiology Network (HyperGEN) study. We excluded participants with severe aortic or mitral stenosis or with known coronary heart disease. Bioimpedance was used to assess body composition. Echocardiography was used to assess left ventricular (LV) structure and function and to calculate myocardial workload (expressed as energy expenditure) from end-systolic stress, ejection time, and stroke volume. The study sample was divided into groups without mitral or aortic regurgitation (control subjects, n = 1175), with mild valvular regurgitation (1+, n = 246), and with at least moderate (>or=2+) mitral or aortic regurgitation (n = 75). RESULTS: The mean patient age was higher with more severe valvular insufficiency. Sex distribution and blood pressure were similar among the 3 groups. Body mass index and fat mass were significantly lower with more severe valvular regurgitation, whereas fat-free mass was only slightly lower in the group with >or=2+ regurgitation compared with control subjects. Skinfold thicknesses (brachial and subscapular) were lower with more severe valvular regurgitation, whereas self-reported physical activity per week was similar among the 3 groups. LV mass and circumferential end-systolic stress were higher with more severe valvular regurgitation. Noninvasively estimated myocardial energy expenditure was slightly higher in participants with 1+ valvular regurgitation and was significantly higher with >or=2+ regurgitation. Ejection fraction was mildly lower with >or=2+ aortic insufficiency, mitral insufficiency, or both. Midwall shortening and stress-corrected midwall shortening did not differ among groups. CONCLUSIONS: In a population-based sample of adults with hypertension and without diabetes mellitus, known coronary heart disease, or significant valvular stenosis, mitral and aortic regurgitation were associated with higher LV mass and total myocardial biomechanical workload but with lower body fat mass and slightly lower body fat-free mass, which suggests that global myocardial bioenergetic expenditure is elevated by concomitant valvular regurgitation beyond the effect of pressure overload caused by hypertension.

Adipose Tissue↗

PubMed2003

The Arg16Gly polymorphism of the beta2-adrenergic receptor and left ventricular systolic function.

BACKGROUND: beta-Adrenergic receptors (ARs), including beta1- and beta2-AR, are involved in modulation of cardiac contractility and heart rate. Arg16Gly, a functional polymorphism in the beta2-AR gene, has been reported to influence exercise capacity in heart failure patients. This study examined the association of the beta2-AR Arg16Gly polymorphism with left ventricular (LV) systolic function in a biethnic population-based sample. METHODS: Echocardiograms and the beta2-AR Arg16Gly polymorphism were analyzed in 267 normotensive (54% African Americans) and 252 severe hypertensive (53% African Americans) adults without coronary heart disease or diabetes. RESULTS: The frequencies of Gly16Gly16, Arg16Gly16, and Arg16Arg16 were 28.1%, 54.3%, and 17.6%, respectively, in normotensives, and 31.4%, 47.6%, and 21.0%, respectively, in hypertensives. In normotensives, the Gly16Gly16 homozygotes displayed greater fractional shortening (35.9% +/- 4.3% v 34.1% +/- 4.7% v 34.0% +/- 3.9%, P =.01), ejection fraction (65.0% +/- 5.8% v 62.5% +/- 6.4% v 62.6% +/- 5.4%, P =.01), midwall shortening (18.6% +/- 1.6% v 17.9% +/- 1.9% v 18.0% +/- 1.6%, P =.02), and stress-corrected midwall shortening (110.1% +/- 9.3% v 106.1% +/- 10.6% v 108.1% +/- 10.8%, P =.03) compared to the Arg16Gly16 and Arg16Arg16 groups. These associations were independent of age, sex, ethnicity, heart rate, body mass index, systolic blood pressure, LV end-diastolic dimension, and field center. No significant associations between the beta2-AR Arg16Gly polymorphism and echocardiographic measures were found in hypertensives. CONCLUSIONS: The Arg16Gly polymorphism of beta2-AR may be a marker for LV chamber function and contractility in normotensive adults.

Adult↗

PubMed2003

Appropriateness of quality indicators for older patients with advanced dementia and poor prognosis.

OBJECTIVES: To evaluate the applicability of process-of-care quality indicators (QIs) to vulnerable elders and to measure the effect of excluding indicators based on patients' preferences and for advanced dementia and poor prognosis. DESIGN: The Assessing Care of Vulnerable Elders (ACOVE) project employed 203 QIs for care of 22 conditions (including six geriatric syndromes and 11 age-associated diseases) for community-based persons aged 65 and older at increased risk of functional decline or death. Relevant QIs were excluded for persons deciding against hospitalization or surgery. A 12-member clinical committee (CC) of geriatric experts rated whether each QI should be applied in scoring quality of care for persons with advanced dementia (AdvDem) or poor prognosis (PoorProg). Using content analysis, CC ratings were formulated into a model of QI exclusion. Quality scores with and without excluded QIs were compared. SETTING: Enrollees in two senior managed care plans, one in the northeast United States and the other in the southwest. PARTICIPANTS: CC members evaluated applicability of QIs. QIs were applied to 372 vulnerable elders in two senior managed care plans. MEASUREMENTS: Frequency and type of QIs excluded and the effect of excluding QIs on quality of care scores. RESULTS: Of the 203 QIs, a patient's preference against hospitalization or surgery excluded 10 and eight QIs, respectively. The CC voted to exclude 81.5 QIs (40%) for patients with AdvDem and 70 QIs (34%) for patients with PoorProg. Content analysis of the CC votes revealed that QIs aimed at care coordination, safety or prevention of decline, or short-term clinical improvement or prevention with nonburdensome interventions were usually voted for inclusion (90% and 98% included for AdvDem and PoorProg, respectively), but QIs directed at long-term benefit or requiring interventions of moderate to heavy burden were usually excluded (16% and 19% included, respectively). About half of QIs aimed at age-associated diseases were voted for exclusion, whereas fewer than one-quarter of QIs for geriatric syndromes were excluded. Thirty-nine patients (10%) in our field trial held preferences or had clinical conditions that would have excluded 68 QIs. This accounted for 5% of all QIs triggered by these 39 patients and 0.6% of QIs overall. The quality score without exclusion was 0.57 and with exclusion was 0.58 (P =.89). CONCLUSION: Caution is required in applying QIs to vulnerable elders. QIs for geriatric syndromes are more likely to be applicable to these individuals than are QIs for age-associated diseases. The objectives of care, intervention burdens, and interval before anticipated benefit affect QI applicability. At least for patients with AdvDem and PoorProg, identification of applicable or inapplicable QIs is feasible. In a community-based sample of vulnerable elders, few QIs are excluded.

Aged↗

PubMed2003

Bicuspid aortic valves in monozygotic twins.

Identical bicuspid valve anomalies were found in monozygotic twins. Screening echocardiography should be considered for first-degree relatives of patients with bicuspid aortic valve.

Adult↗

PubMed2003

Imagent improves endocardial border delineation, inter-reader agreement, and the accuracy of segmental wall motion assessment.

BACKGROUND: This study was conducted to assess the ability of a new echocardiographic contrast agent, Imagent (perflexane lipid microspheres; Alliance Pharmaceutical Corp., San Diego, CA), to improve endocardial border delineation (EBD) and assessment of segmental wall motion (SWM). This was achieved by analysis of inter-reader agreement by echocardiography and comparison with an independent imaging technique, magnetic resonance imaging (MRI). METHODS: Two separate, independent, prospective, randomized, controlled, multicenter trials were conducted at 26 centers and included a total of 409 efficacy-evaluable patients. In Study A 206 patients were randomized to receive either Imagent or saline and in Study B, 203 patients received Imagent with a subset imaged by both echocardiography and MRI. All patients were required to have suboptimal baseline images using fundamental imaging. Images were optimized at baseline prior to contrast and the settings maintained post-contrast. Imagent, a suspension of perfluorohexane-filled spheres with flexible lipid shells, was administered as an IV bolus at 0.125 mg/kg body weight. Gated MRI studies were performed within 48 hours of dosing in a subset of 26 subjects. Six expert independent blinded readers reviewed unpaired noncontrast and contrast exams and scored EBD and SWM. Analysis of inter-reader agreement was performed by comparing the SWM score (1 to 5) recorded by each reader pair. In addition, unanimity between readers for SWM was evaluated. For comparison to MRI, the results from echo readers 4, 5, and 6 were each compared with a single independent MRI reader. RESULTS: The patients enrolled in these clinical trials displayed markedly suboptimal images with 49% and 71% (Study A and Study B) of the segments determined by the readers to be suboptimal prior to contrast administration. All readers recorded statistically significant (P < 0.0001) improvement in total EBD scores following the administration of Imagent. Comparison of noncontrast SWM scores for each pair of echo readers resulted in agreement in an average of 39%, of segments in Study A, and 31% of the segments in Study B. Use of Imagent improved agreement in SWM scores to 65% in Study A, and 48% of segments in Study B (P < 0.0001) for all reader pairs in both studies. Reader unanimity in SWM scores increased from 13% to 41% of the segments with the administration of Imagent. Blinded review of the noncontrast echo examinations resulted in agreement with MRI derived SWM scores in 15% of the segments. The administration of Imagent improved this agreement to 47%, of the segments (P < pr = 0.0005 for each blinded reader). CONCLUSIONS: Use of Imagent during echocardiographic imaging improves EBD, providing a significant improvement in inter-reader agreement in SWM evaluation with echo and greater than a threefold improvement in SWM scoring accuracy with MRI.

Adult↗

PubMed2003

Automated analysis of phase-contrast magnetic resonance images in the assessment of endothelium-dependent flow-mediated dilation.

Measurement of flow-mediated arterial dilation (FMAD) provides information regarding the status of peripheral arterial endothelial function. Although phase-contrast magnetic resonance imaging (PC-MRI) can be used to measure FMAD, the manual analysis of one study (tracing regions of interest and processing data on 100 images) can require six or more hours. To enhance the clinical utility of the PC-MRI assessment of FMAD, we hypothesized that an automated technique (Multi-Stage Intensity Thresholding or MSIT) for determining femoral arterial area and flow before and after cuff inflation over the thigh could be used to evaluate FMAD in a rapid, accurate, and reproducible manner. Compared with manual analysis, automated analysis detected a similar percentage change in peak FMAD between healthy individuals (17.2% vs 16.5%) and patients with congestive heart failure (4.0% vs 5.1%). The correlation between percentage changes in arterial area after cuff release derived manually and automatically was very good (r = 0.93). Analysis time for 100 images averaged 10 minutes with MSIT vs. 6 hours for manual analysis. In conclusion, rapid, accurate assessments of femoral artery FMAD can be obtained using Multi-Stage Intensity Thresholding. This methodology may prove useful for the rapid MRI assessment of peripheral arterial endothelial function in a clinical setting when studying patients with cardiovascular disease.

Algorithms↗

PubMed2003

Influence of fat-free mass on detection of appropriateness of left ventricular mass: the HyperGEN Study.

OBJECTIVES: To evaluate the differences between using height(2.7) or fat-free mass for assessment of the appropriateness of left ventricular mass (LVM) in relation to hemodynamic load, and to evaluate the performance of Doppler as compared with M-mode-derived stroke volume for computation of predicted values of LVM. DESIGN: Cross-sectional. SETTING: Population-based. PARTICIPANTS: We studied 2299 participants from the Hypertension Genetic Epidemiology Network Study (prevalent cardiovascular disease in 342). OUTCOME MEASURES: Individual predicted values of LVM were generated by equations using sex, stroke work (systolic blood pressure x stroke volume by either Doppler or M-mode) and either height(2.7) or fat-free mass, as measures of body build, in 228 normotensive, non-obese, non-diabetic participants. Observed LVM was divided by the predicted value and evaluated as 'excess of LVM'. RESULTS: Among 1957 participants without prevalent cardiovascular disease, obese individuals (n = 1008) were slightly younger than non-obese individuals, whereas diabetic participants (n = 294) were slightly older. Excess of LVM was positively related to body mass index (BMI), independently of echocardiographic method and measure of body build, especially when height(2.7) and m-mode stroke work were used, and was greatest in the presence of concentric left ventricular hypertrophy (P < 0.0001). Excess LVM by height(2.7) was progressively greater than that by fat-free mass, as BMI increased (P < 0.0001). In analyses of covariance of association of prevalent cardiovascular disease with age, sex, race, BMI, and excess of LVM (by each method), methods using height(2.7) were more associated with prevalent cardiovascular disease than were methods using fat-free mass (P < 0.02). CONCLUSIONS: Deviation of LVM from values that compensate hemodynamic load can be similarly identified using different measures of body build and methods to generate stroke work. However, the use of height(2.7) to compute LVM as a percentage of that predicted appears to identify deviations from compensatory values that are independently related to prevalent cardiovascular disease more effectively than does the use of fat-free mass.

Adult↗

PubMed2003

Exercise responses of elderly patients with diastolic versus systolic heart failure.

PURPOSE: Little information is available regarding peak and submaximal exercise performance in elderly heart failure (HF) patients, particularly in those with diastolic dysfunction (DD). Therefore, the purpose of this investigation was to compare exercise responses of elderly patients with HF due to either systolic dysfunction (SD) or DD, to age-matched healthy volunteers (HV). METHODS: Patients with chronic HF > or = 60 yr (N = 119) due to SD (N = 60) or primary DD (N = 59) underwent a maximal cycle ergometry test with expired gas analysis and venous lactate measurement. Twenty-eight HV > or = 60 yr served as a control group. Anaerobic threshold was determined by gas analysis (ATVEN) and by plasma lactate rise (ATLAC). RESULTS: Peak oxygen consumption (VO(2peak)) was significantly (P < 0.001) reduced in both SD and DD patients (13 +/- 0.4 vs 14 +/- 0.4 ml x kg(-1) x min(-1), respectively) versus HV (20 +/- 0.6 ml x kg(-1) x min(-1)). Peak heart rate was reduced in patients versus HV (131 +/- 3 bpm vs 145 +/- 4, respectively; P < or = 0.01), but heart rate at a given submaximal work rate was significantly lower (P < or = 0.01) in HV than in SD and DD patients. ATVEN of 11.8 +/- 0.3 ml x kg(-1) x min(-1) for HV was significantly higher than SD (8.9 +/- 0.2) and DD (9.2 +/- 0.3). Peak lactate concentration was 6.6 +/- 0.6 mmol x kg(-1) x l(-1) in HV and was significantly reduced in both SD and DD HF patients. ATVEN correlated well with ATLAC in HV and in DD patients, but not in SD patients. CONCLUSIONS: Submaximal and peak exercise performance are markedly altered in elderly HF patients compared with age-matched HV but do not appear to be different between SD and DD patients.

Aged↗

PubMed2002

Relation of aortic distensibility determined by magnetic resonance imaging in patients > or =60 years of age to systolic heart failure and exercise capacity.

Aortic stiffness increases with advancing age and is associated with the age-related decline in exercise capacity in healthy persons. Previous studies have suggested that aortic compliance is reduced in heart failure (HF). Older persons with systolic HF can have particularly severe exercise intolerance. However, the relation between increased aortic stiffness and exercise intolerance in elderly patients with systolic HF has not been examined. Therefore, aortic distensibility of the proximal ascending aorta (assessed by magnetic resonance imaging) and exercise tolerance (assessed by maximal exercise ergometry with expired gas analysis) was measured in 28 subjects (10 healthy subjects aged 20 to 30 years, 10 healthy subjects aged > or =60 years, and 8 subjects aged > or =60 years with systolic HF). Compared with healthy older subjects, patients with systolic HF had markedly decreased distensibility of the proximal aorta (0.5 +/- 0.4 vs 2.2 +/- 1.2 10(-3) mm Hg(-1), p <0.002), decreased peak exercise volume of oxygen consumption (VO2) (858 +/- 248 vs 1,436 +/- 344 ml/min, p <0.001), and increased aortic wall thickness (3.6 +/- 0.7 vs 2.9 +/- 0.4 mm, p <0.04). Aortic distensibility was significantly correlated with peak VO2 (r = 0.80, p <0.0001) and remained so even after being adjusted for age and left ventricular (LV) ejection fraction. These data suggest that decreased aortic distensibility may contribute to exercise intolerance in older patients with HF due to LV systolic dysfunction.

Adult↗