Electrocardiographic QRS-T angle and the risk of incident silent myocardial infarction in the Atherosclerosis Risk in Communities study.

Background: Silent myocardial infarction (SMI) accounts for about half of the total number of MIs, and is associated with poor prognosis as is clinically documented MI (CMI). The electrocardiographic (ECG) spatial QRS/T angle has been a strong predictor of cardiovascular outcomes. Whether spatial QRS/T angle also is predictive of SMI, and the easy-to-obtain frontal QRS/T angle will show similar association are currently unknown.

Race and Sex Differences in the Incidence and Prognostic Significance of Silent Myocardial Infarction in the Atherosclerosis Risk in Communities (ARIC) Study.

Background: Race and sex differences in silent myocardial infarction (SMI) are not well established.

Methods And Results: The analysis included 9498 participants from the Atherosclerosis Risk in Communities (ARIC) study who were free of cardiovascular disease at baseline (visit 1, 1987-1989). Incident SMI was defined as ECG evidence of MI without clinically documented MI (CMI) after the baseline until ARIC visit 4 (1996-1998).

Eyewitness to history: Landmarks in the development of computerized electrocardiography.

The use of digital computers for ECG processing was pioneered in the early 1960s by two immigrants to the US, Hubert Pipberger, who initiated a collaborative VA project to collect an ECG-independent Frank lead data base, and Cesar Caceres at NIH who selected for his ECAN program standard 12-lead ECGs processed as single leads. Ray Bonner in the early 1970s placed his IBM 5880 program in a cart to print ECGs with interpretation, and computer-ECG programs were developed by Telemed, Marquette, HP-Philips and Mortara. The "Common Standards for quantitative Electrocardiography (CSE)" directed by Jos Willems evaluated nine ECG programs and eight cardiologists in clinically-defined categories.

A wide QRS/T angle in bundle branch blocks is associated with increased risk for coronary heart disease and all-cause mortality in the Atherosclerosis Risk in Communities (ARIC) Study.

Background: Repolarization abnormality in bundle branch blocks (BBB) is traditionally ignored. This study evaluated the prognostic value of QRS/T angle for mortality in the presence and absence of BBB.

Methods And Results: Total 15,408 participants (mean age 54 years, 55.

Ventricular conduction defects and the risk of incident heart failure in the Atherosclerosis Risk in Communities (ARIC) Study.

Background: We evaluated the risk of incident heart failure (HF) associated with various categories of ventricular conduction defects (VCDs) and examined the impact of QRS duration on the risk of HF.

Methods And Results: This analysis included 14,478 participants from the Atherosclerosis Risk in Communities (ARIC) study who were free of HF at baseline. VCDs (n = 377) were categorized into right and left bundle branch blocks (RBBB and LBBB, respectively), bifascicular BBB (RBBB with fascicular block), indeterminate-type VCD (IVCD), and pooled VCD group excluding lone RBBB.

Bundle branch blocks and the risk of mortality in the Atherosclerosis Risk in Communities study.

Aims: The main objective of our study was to evaluate the associations between different categories of bundle branch blocks (BBBs) and mortality and to consider possible impact of QRS prolongation in these associations.

Methods: This analysis included 15 408 participants (mean age 54 years, 55.2% women, and 26.

Electrocardiographic repolarization-related predictors of coronary heart disease and sudden cardiac deaths in men and women with cardiovascular disease in the Atherosclerosis Risk in Communities (ARIC) study.

Introduction: We evaluated repolarization-related predictors of coronary heart disease (CHD) death and sudden cardiac death (SCD) in men and women with cardiovascular disease (CVD) in the Atherosclerosis Risk in Communities (ARIC) study.

Methods And Results: Hazard ratios (HR) from Cox regression were computed for 11 ECG measures of repolarization in 1384 subjects (50% women) 45 to 65years of age. The average follow-up was 14years.

Subclinical myocardial injury identified by cardiac infarction/injury score and the risk of mortality in men and women free of cardiovascular disease.

Previous studies have explored the ability of the Cardiac Infarction/Injury Score (CIIS) to identify individuals who are high risk for cardiovascular disease (CVD) mortality. However, its prognostic significance among those without CVD in the United States general population has not been established. This analysis included 6,298 participants (mean age 59±13 years, 53% women, 51% nonwhites) from the Third National Health and Nutrition Examination Survey, excluding participants with a history of CVD or electrocardiographic evidence of old myocardial infarction or ischemic ST depression at baseline.

Electrocardiographic repolarization-related variables as predictors of coronary heart disease death in the women's health initiative study.

Background: We evaluated 25 repolarization-related ECG variables for the risk of coronary heart disease (CHD) death in 52 994 postmenopausal women from the Women's Health Initiative study.

Methods And Results: Hazard ratios from Cox regression were computed for subgroups of women with and without cardiovascular disease (CVD). During the average follow-up of 16.

Electrocardiographic left ventricular hypertrophy and the risk of adverse cardiovascular events: a critical appraisal.

This review covers selected electrocardiographic left ventricular hypertrophy (ECG-LVH) studies which have evaluated their prognostic value for adverse cardiovascular (CVD) events. Most ECG-LVH studies have used echocardiographic left ventricular mass (Echo-LVM) as the gold standard for evaluating ECG-LVH criteria. More recently, LVM from magnetic resonance imaging (MRI-LVM) has evolved as the new gold standard.

Usefulness of electrocardiographic QRS/T angles with versus without bundle branch blocks to predict heart failure (from the Atherosclerosis Risk in Communities Study).

Repolarization abnormalities in the setting of bundle branch blocks (BBB) are generally ignored. We used Cox regression models to determine hazard ratios (HRs) with 95% confidence intervals (CIs) for incident heart failure (HF) associated with wide spatial and frontal QRS/T angle (upper twenty-fifth percentile of each) in men and women with and without BBB. This analysis included 14,478 participants (54.

New age- and sex-specific criteria for QT prolongation based on rate correction formulas that minimize bias at the upper normal limits.

Background: Existing formulas for rate-corrected QT (QTc) commonly fail to properly adjust the upper normal limits which are more critical than the mean QTc for evaluation of prolonged QT. Age- and sex-related differences in QTc are also often overlooked. Our goal was to establish criteria for prolonged QTc using formulas that minimize QTc bias at the upper normal limits.

Short-term repeatability of electrocardiographic Tpeak-Tend and QT intervals.

Background: The electrocardiographic (ECG) Tpeak-Tend interval (TpTe) is associated with arrhythmias and sudden cardiac death. TpTe offers a supplementary measure for the QT interval (QT), yet its repeatability has not been established.

Purpose: Evaluate short-term repeatability of TpTe and QT.

Inter-relationship between electrocardiographic left ventricular hypertrophy and QT prolongation as predictors of increased risk of mortality in the general population.

Background: Prolonged-QT commonly coexists in the ECG with left ventricular hypertrophy (ECG-LVH). However, it is unclear whether to what extent QT prolongation coexisting with ECG-LVH can explain the prognostic significance of ECG-LVH, and whether prolonged-QT coexisting with ECG-LVH should be considered as an innocent consequence of ECG-LVH.

Methods And Results: The study population consisted of 7506 participants (mean age, 59.

Race- and sex-associated differences in rate-adjusted QT, QTpeak, ST elevation and other regional measures of repolarization: the Atherosclerosis Risk in Communities (ARIC) Study.

Background: Data are limited about race-and sex-associated differences in prognostically important ECG measures of regional repolarization.

Methods And Results: The normal reference group from the Atherosclerosis Risk in Communities (ARIC) study included 8,676 white and African-American men and women aged 40-65 years. Exclusion criteria included cardiovascular disease, hypertension, diabetes and major ECG abnormalities.

T-wave inversion, QRS duration, and QRS/T angle as electrocardiographic predictors of the risk for sudden cardiac death.

The aim of this study was to investigate the prognostic utility of isolated T-wave inversion (TWI), QRS duration, and QRS/T angle on electrocardiogram at rest as predictors for sudden cardiac death (SCD) and death from all causes. The assessment of electrocardiographic findings was based on a population-based cohort of 1,951 men (age 42 to 61 years) with a follow-up period of 20 years. Isolated TWI in the absence of ST depression, bundle branch block or major arrhythmias, prolonged QRS duration from 110 to 119 ms, and a wide QRS/T angle of >67° were identified from the 12-lead electrocardiograms.

Normal standards for computer-ECG programs for prognostically and diagnostically important ECG variables derived from a large ethnically diverse female cohort: the Women's Health Initiative (WHI).

Background: Substantial new information has emerged recently about the prognostic value for a variety of new ECG variables. The objective of the present study was to establish reference standards for these novel risk predictors in a large, ethnically diverse cohort of healthy women from the Women's Health Initiative (WHI) study.

Methods And Results: The study population consisted of 36,299 healthy women.

Electrocardiographic predictors of incident heart failure in men and women free from manifest cardiovascular disease (from the Atherosclerosis Risk in Communities [ARIC] study).

The risk of incident hospitalized heart failure (HF) was evaluated for 23 electrocardiographic (ECG) variables in men and women free from cardiovascular disease. The hazard ratios with 95% confidence intervals were determined from Cox regression analysis for 13,428 participants 45 to 65 years old in the Atherosclerosis Risk in Communities (ARIC) study. New-onset HF during a 14-year follow-up period occurred in 695 men (11.

Different patterns of bundle-branch blocks and the risk of incident heart failure in the Women's Health Initiative (WHI) study.

Background: We evaluated the risk of incident heart failure (HF) associated with bundle-branch blocks (BBBs) in postmenopausal women.

Methods And Results: Cox's regression was used to evaluate hazard ratios with 95% confidence intervals for HF among 65975 participants of the Women's Health Initiative (WHI) study during an average follow-up of 14 years. BBBs observed in 1676 women at baseline were categorized into left, right, and indetermined-type BBBs (LBBB, RBBB, and intraventricular conduction defect, respectively).

Electrocardiographic predictors of coronary heart disease and sudden cardiac deaths in men and women free from cardiovascular disease in the Atherosclerosis Risk in Communities study.

Background: We evaluated predictors of coronary heart disease (CHD) death and sudden cardiac death (SCD) in the Atherosclerosis Risk in Communities (ARIC) study.

Methods And Results: The study population included 13 621 men and women 45 to 65 years of age free from manifest cardiovascular disease at entry. Hazard ratios from Cox regression with 95% confidence intervals were computed for 18 dichotomized repolarization-related ECG variables.

Isolated negative T waves as independent predictors of short-term and long-term coronary heart disease mortality in men free of manifest heart disease in the Seven Countries Study.

Isolated T-wave findings are generally considered of little importance in clinical electrocardiogram (ECG) interpretation, although a few studies have associated them with excess mortality risk. We used Cox regression models to evaluate coronary heart disease (CHD) mortality risk for isolated inverted T waves in 8713 men in the Seven Countries Study with no manifest cardiac diseases at baseline. The study population was stratified into 3 mutually exclusive groups: (1) isolated inverted T waves in the absence of other codable ECG findings according to the Minnesota Code; (2) other ECG findings with or without negative T waves; and (3) no codable ECG findings, used as the reference group.

Mortality risk associated with bundle branch blocks and related repolarization abnormalities (from the Women's Health Initiative [WHI]).

Electrocardiographic bundle branch block (BBB) has higher cardiac and all-cause death. However, reports on the association between BBBs and mortality in the general populations are conflicting. The aim of this study was to evaluate the risk for coronary heart disease (CHD) and all-cause death associated with left BBB (LBBB) and right BBB (RBBB) during 14 years of follow-up in 66,450 participants from the Women's Health Initiative (WHI) study.