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Background: The prevalence and determinants of QRS transition zones are not well established.Methods: We examined the distributions of Normal, clockwise (CW) and counterclockwise (CCW)) QRS transition zones and their relations to disease, body size and demographics in 4624 black and white men and women free of cardiovascular disease and major ECG abnormalities enrolled in the NHANES-III survey.Results: CW transition zones were least observed (6.2%) and CCW were most prevalent (60.1%) with Normal in an intermediate position (33.7%). In multivariable logistic regression analysis, the adjusted, significant predictors for CCW compared to Normal were a greater proportion of blacks and women, fewer thin people (BMI<20, thin), a greater ratio of chest depth to chest width, and an LVMass index <80g. By contrast, CW persons were older, had larger QRS/T angles, smaller ratio of chest depth to chest width, had a greater proportion of subjects with low voltage QRS, more pulmonary disease, a greater proportion with high heart rates, shorter QRS duration and were more obese (BMI≥30).Conclusions: Normal rather than being the most prevalent transition zone was intermediate in frequency between the most frequently encountered CCW and the least frequently encountered transition zone CW. Differences in the predictors of CW and CCW exist. This requires further investigation to examine how far these differences explain the differences in the published prognostic differences between CW and CCW. [ABSTRACT FROM AUTHOR]

Background: Although silent myocardial infarction (SMI) accounts for about one-half of the total number of myocardial infarctions (MIs), the risk of heart failure (HF) among patients with SMI is not well established.Objectives: The purpose of this study was to examine the association of SMI and clinically manifested myocardial infarction (CMI) with HF, as compared with patients with no MI.Methods: This analysis included 9,243 participants from the ARIC (Atherosclerosis Risk In Communities) study who were free of cardiovascular disease at baseline (ARIC visit 1: 1987 to 1989). SMI was defined as electrocardiographic evidence of MI without CMI after the baseline until ARIC visit 4 (1996 to 1998). HF events were ascertained starting from ARIC visit 4 until 2010 in individuals free of HF before that visit.Results: Between ARIC visits 1 and 4, 305 SMIs and 331 CMIs occurred. After ARIC visit 4 and during a median follow-up of 13.0 years, 976 HF events occurred. The incidence rate of HF was higher in both CMI and SMI participants than in those without MI (incidence rates per 1,000 person-years were 30.4, 16.2, and 7.8, respectively; p < 0.001). In a model adjusted for demographics and HF risk factors, both SMI (hazard ratio [HR]: 1.35; 95% confidence interval [CI]: 1.02 to 1.78) and CMI (HR: 2.85; 95% CI: 2.31 to 3.51) were associated with increased risk of HF compared with no MI. These associations were consistent in subgroups of participants stratified by several HF risk predictors. However, the risk of HF associated with SMI was stronger in those younger than the median age (53 years) (HR: 1.66; 95% CI: 1.00 to 2.75 vs. HR: 1.19; 95% CI: 0.85 to 1.66, respectively; overall interaction p by MI type <0.001).Conclusions: SMI is associated with an increased risk of HF. Future research is needed to examine the cost effectiveness of screening for SMI as part of HF risk assessment, and to identify preventive therapies to improve the risk of HF among patients with SMI. [ABSTRACT FROM AUTHOR]

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.Methods: We examined the association between the spatial and frontal QRS/T angles, separately, with incident SMI among 9498 participants (mean age 54years, 57% women, and 20% African-American), who were free of cardiovascular disease at baseline (visit 1, 1987-1989) from the Atherosclerosis Risk in Communities (ARIC) study. Incident SMI was defined as MI occurring after the baseline until visit 4 (1996-1998) without CMI. The frontal plane QRS/T angle was defined as the absolute difference between QRS axis and T axis. Values greater than the sex-specific 95th percentiles of the QRS/T angles were considered wide (abnormal).Results: A total of 317 (3.3%) incident SMIs occurred during a 9-year median follow-up. In a model adjusted for demographics, cardiovascular risk factors and potential confounders, both abnormal frontal (HR 2.28, 95% CI 1.58-3.29) and spatial (HR 2.10, 95% CI 1.44-3.06) QRS/T angles were associated with an over 2-fold increased risk of incident SMI. Similar patterns of associations were observed when the results were stratified by sex.Conclusions: Both frontal and spatial QRS/T angles are predicative of SMI suggesting a potential use for these markers in identifying individuals at risk. [ABSTRACT FROM AUTHOR]

Background: It has been recently reported that the Romhilt-Estes (R-E) score, originally proposed for detection of left ventricular hypertrophy from the electrocardiogram, is a strong predictor of all-cause mortality. Whether the R-E score is also predictive of cardiovascular disease (CVD) and whether its individual components differ in their ability to predict different CVD outcomes are not well established.Methods: This analysis includes 13,261 participants from the ARIC study who were free of CVD at baseline (1987-1989). Incident CVD, coronary heart disease (CHD), heart failure (HF), and stroke were ascertained by an adjudication committee through December 2010. The R-E left ventricular hypertrophy score was measured from automatically processed baseline electrocardiogram data. Cox proportional hazard models were used to examine the association between baseline the R-E overall score (overall) and each of its 6 individual components separately, with each of the CVD outcomes.Results: During a median follow-up of 21.8 years, 3,579, 2,205, 1,814, and 731 CVD, CHD, HF, and stroke events, respectively, occurred. In multivariable adjusted models, R-E score ≥4 points (compared with 0 points) was associated with increased risk of CVD, CHD, HF, and stroke (hazard ratio [95% CI] 1.66 [1.41-1.96], 1.66 [1.34-2.07], 1.97 [1.60-2.43], and 1.49 [1.07-2.07], respectively). The 6 component of the R-E score varied in their relationship to different CVD outcomes.Conclusions: The R-E score is predictive of CVD outcomes. The 6 R-E score components differ in their associations with different CVD outcomes, indicating that they may be electrical biomarkers of different physiological events within the myocardium. [ABSTRACT FROM AUTHOR]

Background The same electrocardiographic (ECG) criteria that have been used for detection of left ventricular hypertrophy (LVH) have recently been recognized as predictors of adverse clinical outcomes, but this predictive ability is inadequately explored and understood. Methods A total of 14,984 participants from the ARIC study were included in this analysis. Romhilt-Estes (R-E) LVH score was measured from the automatically processed baseline (1987-1989) ECG data. All-cause mortality was ascertained up to December 2010. Cox proportional hazard models were used to examine the association between baseline R-E score, overall and each of its 6 individual components separately, with all-cause mortality. The associations between change in R-E score between baseline and first follow-up visit with mortality were also examined. Results During a median follow-up of 21.7 years, 4,549 all-cause mortality events occurred during follow-up. In multivariable-adjusted models, increasing levels of the R-E score was associated with increasing risk of mortality both as a baseline finding and as a change between the baseline and the first follow-up visit. Of the 6 ECG components of the score, 4 were predictive of all-cause mortality (P-terminal force, QRS amplitude, LV strain, and intrinsicoid deflection), whereas 2 of the components were not (left axis deviation and prolonged QRS duration). Differences in the strengths of the associations between the individual components of the score and mortality were observed. Conclusions The R-E score, traditionally used for detection of LVH, could be used as a useful tool for predication of adverse outcomes. [ABSTRACT FROM AUTHOR]

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, 55.2% women, 26.9% blacks, 2.8% with BBB) were from the Arteriosclerosis Risk in Communities Study. Sex stratified Cox regression models were used to compute hazard ratios (HRs) with 95% confidence intervals (CIs) for coronary heart disease (CHD) and all-cause mortality for wide spatial QRS/T angle with and without BBB including right BBB (RBBB), left BBB (LBBB) and indetermined-type ventricular conduction defect (IVCD) and RBBB combined with left anterior fascicular block. During a median 22-year follow-up, 4767 deaths occurred, 728 of them CHD deaths. Using the No-BBB with QRS/T angle below median value as gender-specific reference groups, the mortality risk increase was significant for both women and men with No-BBB and QRS/T angle above the median value. In the pooled ICVD/LBBB group, the risk for CHD death was increased 15.9-fold in women and 6.04 fold in men, and for all-cause deaths 3.01-fold in women and 1.84-fold in men. However, the mortality risk in isolated RBBB group was only significantly increased in women but not in men. Conclusion A wide spatial QRS/T angle in BBB is associated with increased risk for CHD and all-cause mortality over and above the predictive value for BBB alone. The risk for women is as high as or higher than that in men. [ABSTRACT FROM AUTHOR]

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. During an average of 18 years' follow-up, 1,772 participants were hospitalized for incident HF. Compared with no VCD, LBBB and pooled VCD were strongly associated with increased risk of incident HF (multivariable hazard ratios 2.87 and 2.29, respectively). Compared with no VCD with QRS duration <100 ms, HF risk was 1.17-fold for the no VCD group with QRS duration 100–119 ms, 1.97-fold for the pooled VCD group with QRS duration 120–139 ms, and 3.25-fold for the pooled VCD group with QRS duration ≥140 ms. HF risk for the pooled VCD group remained significant (1.74-fold for QRS duration 120–139 ms and 2.81-fold for QRS duration ≥140 ms) in the subgroup free from cardiovascular disease at baseline. Lone RBBB was not associated with incident HF. Conclusions VCDs except for isolated RBBB are strong predictors of incident HF, and HF risk is further increased as the QRS duration is prolonged >140 ms. [ABSTRACT FROM AUTHOR]

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 65 years of age. The average follow-up was 14 years. Based on electrophysiological considerations the spatial angle between Tpeak and normal repolarization reference vector [Ѳ(Tp|Tref)], STJV6 amplitude, QRS duration and Tonset and Tpeak vector magnitude ratio (ToV/TpV) were considered as primary candidates for independent mortality predictors, and as an alternative set TaVR and TV1 amplitudes and the spatial angle between the initial and terminal T vectors [Ѳ(Tinit|Tterm)]. From the primary set [Ѳ(Tp|Tref)] was a strong independent predictor for CHD death (nearly 4-fold increased risk in men and 2-fold increased risk in women) and for SCD [Ѳ(Tinit|Tterm)] in men (3.4-fold increased risk) and (ToV/TpV) in women (7.76-fold increased risk). From the alternative set of independent predictors TaVR amplitude negativity reduced to less than 150 μV (1.5 mm) was a strong mortality predictor with an approximately 3-fold increased risk for CHD death and SCD in men and women. Conclusions The strongest independent predictors of CHD death were [Ѳ(Tp|Tref)] in men and TaVR in women and of SCD were [Ѳ(Tp|Tref)] in men and ToV/TpV in women. Overall, TaVR amplitude negativity reduced to less than 150 μV (1.5 mm) was the most consistent mortality predictor in all subgroups. These ECG variables may warrant consideration for identification of high risk men and women for more intense preventive intervention. [ABSTRACT FROM AUTHOR]

Abstract: 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 40–65years. Exclusion criteria included cardiovascular disease, hypertension, diabetes and major ECG abnormalities. Notable sex differences (p<0.001) were observed in the upper 98% limits for rate-adjusted QTend (QTea) which was 435ms in white and African-American men and 445ms in white and African-American women, and for left ventricular epicardial repolarization time (RTepi) which was 345ms in white and African-American men and 465ms in white and African-American women. These sex differences reflect earlier onset and end of repolarization in men than in women. Upper normal limits for STJ amplitude in V2–V3 were 100μV in white and African-American women, 150μV in white men and 200μV in African-American men (p<0.001 for sex differences), and for other chest leads, aVL and aVF 50μV in white women, 100μV in African-American women, 100μV in white men and 150μV in African-American men (p<0.001 for sex and race differences). Conclusions: Shorter QTea and RTepi in men than in women reflect earlier onset and end of repolarization in men. STJ amplitudes in African-American men were higher than in other subgroups by race and sex. These sex and race differences need to be considered in clinical and epidemiological applications of normal standards. [Copyright &y& Elsevier]

Abstract: Background: A widened electrocardiographic spatial QRS-T angle has been shown to be predictive of cardiovascular disease in HIV-infected individuals. However, determinants and risk factors of developing widened QRS-T angle over time in this population remain unknown. Methods and Results: Spatial QRS-T angle was automatically measured from standard electrocardiogram of 1444 HIV-infected individuals without baseline widened spatial QRS-T angle from the Strategies for Management of Antiretroviral Therapy [SMART], a clinical trial comparing two antiretroviral treatment strategies [Drug Conservation (DC) vs. Viral Suppression (VS)]. Conditional logistic regression analysis was used to examine the association between baseline characteristics and incident widened spatial QRS-T angle (a new angle > 93° in males and > 74° in females). During 2544 person-years of follow-up, 199 participants developed widened angle at a rate of 7.8 per 100 person-years. In unadjusted models, female sex, black race (vs. white), DC treatment strategy, current and past smokers (vs. never), history of alcohol abuse, greater body mass index, history of diabetes and higher levels of hs-C-reactive protein were associated with incident widened spatial QRS-T angle. When these variables were entered together in the same model with adjustment for demographics and treatment strategy, DC treatment strategy [OR (95% CI): 1.50 (1.09, 2.07)], female gender [1.69 (1.17, 2.45)], current and past smoking (vs. never) [2.49 (1.63, 3.81) and 1.93 (1.21, 3.09), respectively], and diabetes [2.28 (1.33, 3.91)] predicted incident widened spatial QRS-T angle. Conclusions: Drug conservation treatment strategy, female gender, smoking, and diabetes are independently predictive of incident widened spatial QRS-T angle in HIV-infected individuals. [Copyright &y& Elsevier]

Abstract: 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. Racial differences in rate-adjusted QT end (QTea) and QT peak (QTpa) intervals as linear functions of RR were small, leading to the conclusion that 450 and 390ms are applicable as thresholds for prolonged and shortened QTea and similarly, 365 and 295ms for prolonged and shortened QTpa, respectively. As a threshold for increased dispersion of global repolarization (TpeakTend interval), 110ms was established for white and Hispanic women and 120ms for African-American and Asian women. ST elevation and depression values for the monitoring leads of each person with limb electrodes at Mason-Likar positions and chest leads at level of V1 and V2 were first computed from standard leads using lead transformation coefficients derived from 892 body surface maps, and subsequently normal standards were determined for the monitoring leads, including vessel-specific bipolar left anterior descending, left circumflex artery and right coronary artery leads. The results support the choice 150μV as a tentative threshold for abnormal ST-onset elevation for all monitoring leads. Body mass index (BMI) had a profound effect on Cornell voltage and Sokolow–Lyon voltage in all racial groups and their utility for left ventricular hypertrophy classification remains open. Conclusions: Common thresholds for all racial groups are applicable for QTea, and QTpa intervals and ST elevation. Race-specific normal standards are required for many other ECG parameters. [Copyright &y& Elsevier]

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. Cox proportional-hazards regression was performed for mortality risk in Women with LBBB (n = 714) and those with RBBB (n = 832). In risk models adjusted for demographic and clinical risk factors in women with cardiovascular disease (CVD), hazard ratios for CHD death were 2.92 (95% confidence interval 2.08 to 4.08, p <0.001) for LBBB and 1.62 (95% confidence interval 1.08 to 2.43, p <0.05) for RBBB, and only LBBB was a significant predictor of all-cause death (hazard ratio 1.43, 95% confidence interval 1.11 to 1.83, p <0.01). In CVD-free women, only LBBB was a significant predictor of CHD death (fully adjusted hazard ratio 2.17, 95% confidence interval 1.37 to 3.43, p <0.01), and neither blocks was predictive of all-cause death. From several repolarization variables that were significant mortality predictors in univariate risk models, after adjustment for other electrocardiographic covariates and risk factors, ST J-point depression in lead aVL ≤−30 μV in women with LBBB was an independent predictor of CHD death, with a more than fivefold increase in risk. None of the repolarization variables were independent predictors in women with RBBB. In conclusion, prevalent LBBB in CVD-free women and LBBB and RBBB in women with CVD were significant predictors of CHD death. In women with LBBB, ST J-point depression in lead aVL was a strong independent predictor of CHD death. [Copyright &y& Elsevier]

Spatial QRS/T angle and spatial T-wave axis were shown to be strong independent predictors of incident coronary heart disease (CHD) and total mortality, but they are not routinely available. We evaluated whether frontal plane QRS/T angle, easily obtained as the difference between frontal plane axes of QRS and T, provides a suitable substitute for spatial QRS/T angle as a risk predictor. Our study consisted of 13,973 participants from the ARIC Study. Outcome variables were incident CHD and total mortality during a median follow-up of 14 years. Electrocardiographic variables were categorized as abnormal (≥95th percentile), borderline (≥75th and <95th percentile), and normal (<75th percentile) separately for men and women. Cox regression was used to assess the effect of electrocardiographic variables on risk of each outcome. The normal category was considered the reference cell. With adjustment for demographic and clinical characteristics, both QRS/T angles were approximately equally strong predictors of total mortality with >50% increased risk. Spatial QRS/T angle was a stronger predictor of incident CHD in women, with a 114% increased risk, but it was not significantly associated with risk of incident CHD in men. Similarly, frontal plane QRS/T angle was statistically significant for only women with a 74% increased risk of incident CHD. In conclusion, frontal plane QRS/T angle as an easily derived risk measure is a suitable clinical substitute for spatial QRS/T angle for risk prediction. [Copyright &y& Elsevier]

Abstract: The spatial QRS/T angle has been identified as a strong predictor of adverse cardiac events. Mean QRS and T amplitudes from X, Y, and Z leads generated by a matrix transformation method are often used to calculate the QRS/T angle (QRS/Tmatrix). Many investigators find this procedure cumbersome. We used electrocardiographic data files of 14881 men and women aged 45 to 65 years from the Atherosclerosis in Communities study to derive a simple formula for estimated spatial QRS/T angle (QRS/Tsimple). QRS/Tsimple is calculated as the inverse cosine between the mean QRS and T vectors, which are approximated by 3 QRSnet and Tnet amplitudes for each vector. QRS/Tsimple explained 79% of the variance of QRS/Tmatrix (r = 0.89). Using sex-specific thresholds, QRS/Tsimple detected abnormally wide QRS/Tmatrix values with a sensitivity of 91% and specificity of 88%. It is concluded that this simple method may provide a satisfactory substitute for QRS/T from the matrix transformation method. [Copyright &y& Elsevier]

The JT interval or Bazett''s QTc − QRS has been advocated for detection of prolonged repolarization in ventricular conduction defects (VCDs). However, the use of neither JT nor QTc − QRS has been validated, and normal limits for rate-adjusted JT have not been established for VCDs or for normal ventricular conduction. Functional relations among RR, JT, and QT intervals were evaluated in 11,739 adult men and women with normal ventricular conduction and in 1,251 subjects with major VCD. The results showed that JT adjustment obtained as QTc − QRS retained a strong residual correlation with ventricular rate (r = 0.54), making its use ill-advised. In contrast, QT adjustment as a linear function of the RR interval for VCD as QTRR,QRS = QT − 155 × (60/heart rate − 1) − 0.93 × (QRS − 139) + k, with k = −22 ms for men and −34 ms for women, removed the rate dependence and produced upper 2% and 5% normal limits at 460 and 450 ms, respectively, which are identical to those in normal conduction. As an alternative, equally effective linear JT adjustment formulas were derived, including newly required normal standards. Thus, detection of prolonged repolarization in VCD requires the use of the JT interval or a bivariate model for QT with RR and QRS intervals as covariates. [Copyright &y& Elsevier]

The Minnesota Code (MC) and Novacode (Nova) are the most widely used electrocardiographic (ECG) classification systems. The comparative strengths of their classifications for Q- and ST-T–wave abnormalities in predicting coronary heart disease (CHD) events and total mortality have not been evaluated separately by gender. We studied standard 12-lead electrocardiograms at rest from 4,988 participants in the Cardiovascular Health Study. Average age at baseline was 73 years, 60% of participants were women 85% were white, and 22% had a history of cardiovascular disease or presence of ECG myocardial infarction by MC or Nova. Starting in 1989 with an average 17-year follow-up, 65% of participants died and 33% had incident CHD in a cohort free of cardiovascular disease at baseline. Of these, electrocardiograms with major Q-wave or major ST-T abnormalities by MC or Nova predicted increased risk for CHD events and total mortality with no significant differences in predictability between men and women. The study also found that women had fewer major Q-wave changes but more major ST-T abnormalities than men. However, there were no gender differences in predicting CHD events and total mortality. In conclusion, ECG classification systems for myocardial infarction/ischemia abnormalities by MC or Nova are valuable and useful for men and women in clinical trials and epidemiologic studies. [ABSTRACT FROM AUTHOR]

Electrocardiographic (ECG) Q- and ST-T–wave abnormalities predict coronary heart disease (CHD) and total mortality. No comparison has been made of the classification of these abnormalities by the 2 most widely used ECG coding systems for epidemiologic studies—the Minnesota Code (MC) and Novacode (NC). We evaluated 12-lead electrocardiograms from 64,597 participants (49 to 79 years old, 82% non-Hispanic white) in the Women''s Health Initiative clinical trial in 1993 to 1998, with a maximum of 11 years of follow-up. We used MC and NC criteria to identify Q-wave, ST-segment, and T-wave abnormalities for comparison. In total, 3,322 participants (5.1%) died during an average 8-year follow-up, and 1,314 had incident CHD in the baseline cardiovascular disease-free group. Independently, ECG myocardial infarction criteria by the MC or NC were generally equivalent and were strong predictors for CHD death and total mortality (hazard ratio 1.62, 95% confidence interval 1.05 to 2.51 for CHD death; hazard ratio 1.36, 95% confidence interval 1.09 to 1.71 for total mortality) in a multivariable analytic model. Electrocardiograms with major ST-T abnormalities by the MC or NC coding system were stronger in predicting CHD deaths and total mortality than was the presence of Q waves alone. In conclusion, the ECG classification systems for myocardial infarction/ischemia abnormalities from the MC and NC are valuable and useful in clinical trials and epidemiologic studies. ST-T abnormalities are stronger predictors for CHD events and total mortality than isolated Q-wave abnormalities. [Copyright &y& Elsevier]

A United States national sample of 20,962 participants (57% women, 44% blacks) from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study provided general population estimates for electrocardiographic (ECG) abnormalities among black and white men and women. The participants were recruited from 2003 to 2007 by random selection from a commercially available nationwide list, with oversampling of blacks and those from the stroke belt, with a cooperation rate of 49%. The measurement of risk factors and 12-lead electrocardiograms (centrally coded using Minnesota code criteria) showed 28% had ≥1 major ECG abnormality. The prevalence of abnormalities was greater (≥35%) for those ≥65 years old, with no differences between blacks and whites. However, among men <65 years, blacks had more major abnormalities than whites, most notably for atrial fibrillation, major Q waves, and left ventricular hypertrophy. Men generally had more ECG abnormalities than women. The most common ECG abnormalities were T-wave abnormalities. The average heart rate-corrected QT interval was longer in women than in men, similar in whites and blacks, and increased with age. However, the average heart rate was greater in women than in men and in blacks than in whites and decreased with age. The prevalence of ECG abnormalities was related to the presence of hypertension, diabetes, blood pressure, and age. In conclusion, black men and women in the United States have a significantly greater prevalence of ECG abnormalities than white men and women at age 45 to 64 years; however, these proportions, although larger, tended to equalize or reverse after age 65. [Copyright &y& Elsevier]

Abstract: Objective: Our aim was to determine if silent myocardial infarction (MI) is more common in women with type 2 diabetes than in men. Our secondary aim was to examine the relationships between silent MI and risk factors for cardiovascular disease. Research design and methods: The Action to Control Cardiovascular Risk in Diabetes (ACCORD) database was used to determine if women had more silent MI on baseline electrocardiograms (ECGs) than did men with a similar unremarkable cardiovascular history. MI was diagnosed using ECG analysis according to the Minnesota code. Multivariable logistic regression analysis was used to compare demographic and clinical associations. Interactive effects of risk factors by gender were tested using a forward selection algorithm. Results: Men were found to have a higher prevalence of silent MI on baseline ECGs than women (6% vs 4%, P = .001). Women had lower odds of silent MI than men after adjusting for other risk factors (OR = 0.80, P = .04). Race and ethnicity were significantly associated with silent MI (P = .02), with Asians having the highest and African Americans and Hispanics having lower odds relative to whites. Conclusions: Our main findings provide no evidence that silent MI, as detected by the Minnesota code, was more common in women than in men in the ACCORD cohort. If, as in the general population, the women in ACCORD are found to have a higher heart disease mortality rate than the men, it seems unlikely that failure to recognize clinically silent heart disease in the years before study enrollment could be a major cause. [Copyright &y& Elsevier]

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 V5), with the remaining deciles as reference groups. Risk models were adjusted for demographic and clinical variables. In univariate Cox regression models, in men 11 and in women 8 of the 12 ECG variables were significant, strong predictors of risk of new-onset HF. Subsequently, 8 ECG variables with low mutual correlations were entered simultaneously into a multivariate Cox regression model. In men, large left ventricular mass by electrocardiogram, QT prolongation, and increased heart rate were the strongest independent predictors of new-onset HF, each with a twofold increased risk. Other independent predictors in men were ST depression in lead V5, wide QRS/T angle, and old (silent) myocardial infarction, each with a >50% increased risk of incident HF. In women, QRS nondipolar voltage was associated with an 87% increased risk of incident HF, and other independent predictors, as in men, were wide QRS/T angle and increased heart rate. In conclusion, several ECG abnormalities are manifestations of evolving HF in men and women considered free of coronary heart disease. [Copyright &y& Elsevier]

Mortality risk associated with electrocardiographic (ECG) abnormalities has been commonly reported to be lower in women than in men. We compared coronary heart disease (CHD) and all-cause mortality risk for ECG variables during a mean 9.1-year follow-up in 4,912 participants in the Cardiovascular Health Study who were ≥65 years of age. The hypothesis was that mortality risk for ECG abnormalities is not lower in women than in men. Five ECG variables were significant mortality predictors in Cox regression models that were adjusted for demographic, clinical, and medication variables. Gender differences were significant and mortality risk was higher in women for ECG estimates of left ventricular mass for both end points and for nondipolar QRS voltage for all-cause mortality. When evaluated simultaneously in multiple ECG variable risk models in subgroups that were stratified by baseline CHD status, no gender difference was significant. In the latter models, ST depression was a strong predictor of CHD mortality in groups with and without previous CHD. Other significant ECG predictors were previous myocardial infarction in the previous CHD group and nondipolar QRS voltage in the CHD-free group. Four ECG abnormalities were significant predictors of all-cause mortality in the CHD-free group, with risk increases of 18% to 50%. The risk of all-cause mortality in the previous CHD group was significantly increased for ST depression (by 64%), the ECG estimate of left ventricular mass (by 48%), and previous myocardial infarction (by 34%). In conclusion, we found no evidence that the relative risk of mortality for ECG abnormalities is lower in women than in men. [Copyright &y& Elsevier]