Publications by authors named "Richard Crow"

Purpose: To examine whether a subjective measure of moderate-intensity exercise (12-13 on Borg's ratings of perceived exertion scale; RPE) corresponds to the target heart rate for moderate-intensity exercise (40-59% heart rate reserve; %HRR) and to determine the characteristics of those for whom RPE does not appropriately estimate exercise intensity.

Methods: 3582 individuals with type 2 diabetes (age: 58.3±6.

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Although the incidence of and mortality after ST-segment elevation myocardial infarction (STEMI) is decreasing, time trends in anatomical location of STEMI and associated short-term prognosis have not been examined in a population-based community study. We determined 22-year trends in age- and race-adjusted gender-specific incidences and 28-day case fatality of hospitalized STEMI by anatomic infarct location among a stratified random sample of 35- to 74-year-old residents of 4 communities in the Atherosclerosis Risk in Communities study. STEMI infarct location was assessed by 12-lead electrocardiograms from the hospital record and was coded as anterior, inferior, lateral, and multilocation STEMIs using the Minnesota code.

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Background: Weight loss is recommended for overweight or obese patients with type 2 diabetes on the basis of short-term studies, but long-term effects on cardiovascular disease remain unknown. We examined whether an intensive lifestyle intervention for weight loss would decrease cardiovascular morbidity and mortality among such patients.

Methods: In 16 study centers in the United States, we randomly assigned 5145 overweight or obese patients with type 2 diabetes to participate in an intensive lifestyle intervention that promoted weight loss through decreased caloric intake and increased physical activity (intervention group) or to receive diabetes support and education (control group).

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Aims: An association has been described between death from arrhythmia and early repolarization, an electrocardiogram pattern characterized by elevation of the QRS-ST junction (J-point). Little is known about this relationship in non-white populations. This study examines the relationship between J-point elevation (JPE) and sudden cardiac death (SCD) and whether this relationship differs by race or sex.

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Atrial fibrillation and obesity are increasing in prevalence and are interrelated epidemics. There has been limited assessment of how obesity and the metabolic syndrome impact P wave indices, established electrocardiographic predictors of atrial fibrillation. We conducted a cross-sectional analysis to determine the association of obesity and the components of the metabolic syndrome with P wave indices in the population-based Atherosclerosis Risk in Communities (ARIC) study.

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A risk score for atrial fibrillation (AF) has been developed by the Framingham Heart Study; however, the applicability of this risk score, derived using data from white patients, to predict new-onset AF in nonwhites is uncertain. Therefore, we developed a 10-year risk score for new-onset AF from risk factors commonly measured in clinical practice using 14,546 subjects from the Atherosclerosis Risk In Communities (ARIC) study, a prospective community-based cohort of blacks and whites in the United States. During 10 years of follow-up, 515 incident AF events occurred.

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Purpose: To estimate the association of age with maximal HR (MHR).

Methods: Data were obtained from the Coronary Artery Risk Development in Young Adults (CARDIA) study. Participants were black and white men and women aged 18-30 yr in 1985-1986 (year 0).

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Objectives: The ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial) determined that treatment with amlodipine, lisinopril, or doxazosin was not superior to thiazide-like diuretic (chlorthalidone) in preventing coronary heart disease (CHD) or other cardiovascular events. This subanalysis examines baseline prevalence and in-trial incidence of new-onset atrial fibrillation (AF) or atrial flutter (AFL) and their influence on clinical outcomes.

Background: Limited information is available on whether atrial fibrillation incidence is affected differentially by different classes of antihypertensive medications or treatment with statins.

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Background: Electrocardiographic QT interval prolongation is a risk factor for sudden cardiac death and drug-induced arrhythmia. The clinical correlates and heritability of QT interval duration in blacks have not been well studied despite their higher risk for sudden cardiac death compared with non-Hispanic whites. We sought to investigate potential correlates of the QT interval and estimate its heritability in the Jackson Heart Study.

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Heart rate (HR) profile during exercise predicts all-cause mortality. However, less is known about its relation to sudden (vs nonsudden) death in asymptomatic people. The relation of exercise HR parameters (HR at rest, target HR achievement, HR increase, and HR recovery) with sudden death, coronary heart disease (CHD) death, myocardial infarction, and all-cause mortality was assessed in 12,555 men who participated in MRFIT.

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We compared the prognostic value of 12 electrocardiographic (ECG) variables in predicting risk of new-onset heart failure (HF) in a subgroup of 13,555 participants of the Atherosclerosis Risk in Communities (ARIC) study who were considered free of coronary heart disease at the onset of the study. Cox proportional hazards models were used to evaluate risk of HF for the highest decile of the distribution of each ECG variable (lowest decile for ST and T amplitudes in lead V(5)), with the remaining deciles as reference groups. Risk models were adjusted for demographic and clinical variables.

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Background: Electrocardiographic (ECG) findings are known to differ by race, however, systematic comparisons of findings between eastern and western countries are rare.

Objective: To compare the ECG findings and associated coronary heart disease (CHD) risk factors between Taiwan Chinese and US White adults aged >or=40 years.

Methods: We compared the prevalence rate of Minnesota Code criteria based ECG findings and associated CHD risk factors by using data from the third National Health and Nutrition Examination Survey (NHANES III) and the Nutrition and Health Survey in Taiwan (NAHSIT, 1993-1996).

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Objective: We examined associations of cardiovascular, metabolic, and body composition measures with exercise capacity using baseline data from 5,145 overweight and/or obese (BMI > or = 25.0 kg/m2) men and women with type 2 diabetes who were randomized participants for the Look AHEAD (Action for Health in Diabetes) clinical trial.

Research Design And Methods: Peak exercise capacity expressed as METs and estimated from treadmill speed and grade was measured during a graded exercise test designed to elicit a maximal effort.

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Objective: Cardiovascular disease is a major cause of morbidity and mortality in individuals with type 1 diabetes. Resting heart rate (RHR) is a risk factor for cardiovascular disease in the general population, and case-control studies have reported a higher RHR in individuals with type 1 diabetes. In individuals with type 1 diabetes, there is a positive correlation between A1C and RHR; however, no prospective studies have examined whether a causal relationship exists between A1C and RHR.

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Recent findings associate periodontal disease with established coronary heart disease (CHD) and with disorders of the carotid artery. Besides measures of the carotid artery, a number of other noninvasive subclinical markers of cardiovascular disease exist and are summarized here. Included are computed tomography (CT) of the coronary arteries, ultrasound of the carotid arteries, echocardiography, magnetic resonance imaging (MRI), ankle-brachial index, microalbuminuria, and other biochemical measures of kidney dysfunction, flow-mediated dilation in the brachial artery, and pulse wave form analysis.

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The clinical relevance of ventricular premature complexes (VPCs) in apparently healthy patients is not clear and is typically not considered when evaluating risk. We conducted a prospective longitudinal study of the population-based Atherosclerosis Risk In Communities (ARIC) study of 15,070 Caucasians and African-Americans, 45 to 64 years of age, to assess the risks of coronary heart disease (CHD) events and mortality associated with VPCs among participants with and without prevalent CHD at baseline. VPCs on a single 2-minute electrocardiogram were identified in 940 participants (6.

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Background: Hypertension is a major cause of heart failure (HF) and is antecedent in 91% of cases. The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) stipulated assessment of the relative effect of chlorthalidone, lisinopril, and amlodipine in preventing HF.

Methods And Results: ALLHAT was a double-blind, randomized, clinical trial in 33,357 high-risk hypertensive patients aged > or =55 years.

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The associations of many electrocardiographic (ECG) abnormalities at rest with incident coronary heart disease (CHD) are not completely established, and whether individual ECG abnormalities convey similar risk across gender and race is uncertain. We studied the independent association of several ECG findings with incident CHD, testing for effect modification by gender and race, in a large, population-based, prospective cohort study. Findings from the baseline 12-lead electrocardiograms in 1987 to 1989 were classified according to the Minnesota Code in 12,987 black and white men and women, aged 45 to 64 years, who were initially free of CHD and the use of specific cardiac medications.

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Long-term trends in epidemiologic studies of acute myocardial infarction (AMI) require application of a consistent diagnostic algorithm. Typically an algorithm includes chest pain, cardiac enzymes, electrocardiographic findings, and autopsy results. The Minnesota Heart Survey (MHS) has determined trends for incident AMI and for in-hospital and long-term outcomes over a 25-year period (1970-1995).

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Background: Although current evidence suggests that the spatial T wave axis captures important information about ventricular repolarization abnormalities, there are only a few and discordant epidemiologic studies addressing the ability of the spatial T wave axis to predict coronary heart disease (CHD) occurrence.

Methods: This prospective study analyzed data from 12,256 middle-aged African American and white men and women, from the Atherosclerosis Risk in Communities Study (ARIC). Following a standardized protocol, resting standard 12-lead, 10-second electrocardiograms were digitized and analyzed with the Marquette GE program.

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Background: Cardiovascular disease (CVD) is the leading cause of death in the United States. In comparison to whites, African-Americans have a higher risk of dying from CVD and have a worse risk factor profile. The Jackson Heart Study (JHS) is designed to investigate the origin and natural history of CVD in African-Americans.

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Objectives: We aimed to study the predictive value of heart rate-corrected QT interval (QTc) for incident coronary heart disease (CHD) and cardiovascular disease (CVD) mortality in the black and white general population, and to validate various QT measurements.

Background: QTc prolongation is associated with higher risk of mortality in cardiac patients and in the general population. Little is known about the association with incident CHD.

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Background: Heart rate-corrected QT interval (QTc) is the traditional method of assessing the duration of repolarization. Prolonged heart rate-corrected QT interval is associated with higher risk of mortality in patients with coronary heart disease (CHD) and in the general population. However, the QTc is typically not evaluated when QRS duration is > or =120 ms, because increased QRS duration (QRSd) contributes to QT interval prolongation.

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