Methodology of ECG Interpretation in the Dalhousie Program; NOVACODE ECG Classification Procedures for Clinical Trials and Population Health Surveys

Rautaharju, P. M.; MacInnis, Paul J.; Warren, James W.; Wolf, Hermann K.; Rykers, Petra M.; Calhoun, Harry P.

doi:10.1055/s-0038-1634798

Cited by 157 publications

(86 citation statements)

References 23 publications

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“…They also did not use a prediction equation for FEV 1 to adjust for differences in age, sex, height, and race of study participants, which could have led to residual confounding by these variables. 17 More importantly, the study by Cirillo et al 27 did not evaluate the role of airflow obstruction (or its severity) on systemic inflammation. We have extended the findings of Cirillo et al 27 and have shown that moderate to severe (but not mild) COPD is strongly associated with systemic low-grade inflammation and ECG evidence of ischemic heart disease.…”

Section: Discussionmentioning

confidence: 99%

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Why Are Patients With Chronic Obstructive Pulmonary Disease at Increased Risk of Cardiovascular Diseases?

2003

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Background-Chronic obstructive pulmonary disease (COPD) increases the risk of cardiovascular disease 2-to 3-fold.The factors responsible for this association remain largely unknown. Methods and Results-We analyzed data from participants, Ն50 years of age, of the Third National Health and Nutrition Examination Survey (nϭ6629) to determine whether C-reactive protein (CRP) and other systemic inflammatory markers are present in participants with chronic airflow obstruction and are associated with cardiac injury. Participants with severe airflow obstruction had circulating leukocyte, platelet, and fibrinogen levels that were 460/L (95% confidence interval [CI], 30 to 890/L), 39 510/L (95% CI, 21 730 to 57 290/L), and 41.63 mg/dL (95% CI, 19.87 to 63.39 mg/dL) higher, respectively, than in those without airflow obstruction. They were also 2.18 times (95% CI, 1.46 to 3.27) more likely to have an elevated circulating CRP level. Moderate airflow obstruction was associated with smaller but still significant increases in these levels. Moderate and severe airflow obstruction was associated with increased occurrence of ischemic changes on electrocardiograms of participants. In the presence of both highly elevated CRP and moderate or severe airflow obstruction, the Cardiac Infarction Injury Score was 2.68 and 5.88 U higher, respectively, than in those without airflow obstruction and with low CRP, which suggests an additive effect of CRP and COPD on the risk of cardiac injury. Conclusion-Low-grade systemic inflammation was present in participants with moderate to severe airflow obstruction and was associated with increased risk of cardiac injury. This may in part explain the high rates of cardiovascular complications in COPD.

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Section: Discussionmentioning

confidence: 99%

“…17 NOVACODE ECG classification procedures were used to estimate left ventricular mass index of study participants. 17 Left ventricular mass indexes of Ͼ150 g/m 2 for men and Ͼ120 g/m 2 for women were used as cutoff points to define left ventricular hypertrophy. 15 …”

Section: Spirometry and Electrocardiographymentioning

confidence: 99%

Why Are Patients With Chronic Obstructive Pulmonary Disease at Increased Risk of Cardiovascular Diseases?

2003

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“…3 All ECGs were processed in a central laboratory (EPICARE Center, Wake Forest University, NC), and they were all visually inspected for technical errors and inadequate quality. ECGs were initially processed by the Dalhousie ECG program, 4 and processing was later repeated for the present study by the 2001 version of the Marquette 12-SL program (GE Marquette). The variables of key interest considered as initial candidates for risk prediction included some ECG waveform descriptors derived by the Novacode program.…”

Section: Ecg Methodologymentioning

confidence: 99%

Electrocardiographic Predictors of Incident Congestive Heart Failure and All-Cause Mortality in Postmenopausal Women

et al. 2006

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Background-Information is limited about ECG predictors of the risk of incident congestive heart failure (CHF), particularly in women without overt manifestations of cardiovascular disease (CVD). Methods and Results-We evaluated hazard ratios for incident CHF and all-cause mortality using Cox regression in 38 283 participants of the Women's Health Initiative (WHI) during a 9-year follow-up. All risk models were adjusted for demographic and available clinical and therapeutic variables (multivariable-adjusted models). A backward selection procedure was used to identify dominant predictors among those that were significant as individual ECG predictors. Eleven ECG variables were significant predictors of incident CHF, with none of them having a significant interaction with baseline CVD status. From 6 dominant ECG predictors, wide QRS/T angle had a nearly 3-fold increased risk in multivariable-adjusted single ECG variable models. Two other repolarization variables, STV 5 depression and high TV 1 amplitude, and 2 QRS-related variables, QRS non-dipolar voltage and myocardial infarction (MI) by ECG, were all associated with Ϸ2-fold increase of incident CHF risk. Overall, 11 of the 12 ECG variables were significant predictors of all-cause mortality. Four variables had a significant interaction with CVD status requiring stratification. Three among these 4 were strong, dominant predictors in the CVD group: ECG MI, wide QRS/T angle, and low TV 5 amplitude had risk increase from Ͼ2-fold to 3-fold, with considerably lower risks in the CVD-free group. Conclusions-Several

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“…A 10-s segment of simultaneous ECG leads was sampled at a rate of 250 samples/s. ECGs were transmitted daily to the Epidemiological Cardiology Research Center (WinstonSalem, NC) for analysis and classification using the Minnesota code derived from the NOVACODE ECG program (17,18). Multiple editing removed poor quality tracings.…”

Section: Measurementsmentioning

confidence: 99%

The Association Among Autonomic Nervous System Function, Incident Diabetes, and Intervention Arm in the Diabetes Prevention Program

et al. 2006

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OBJECTIVE -Autonomic nervous system dysfunction, a correlate of obesity and poor cardiorespiratory fitness, is associated with the development of diabetes. We tested whether estimates of autonomic nervous system function improved in the intensive lifestyle versus metformin or placebo arms of the Diabetes Prevention Program (DPP) and whether baseline or a change in autonomic nervous system function was associated with the development of diabetes over 3.2 years.RESEARCH DESIGN AND METHODS -In 2,980 DPP participants, 12-lead electrocardiograms were measured at baseline and annually. Heart rate, heart rate variability (HRV), and QT duration were used to estimate fitness and autonomic nervous system function.RESULTS -In the lifestyle arm, heart rate and QT indexes decreased, and HRV increased over time. The magnitude of decline in heart rate and QT duration was substantially smaller in the other arms, whereas HRV did not increase. Baseline heart rate was the only index significantly (P Ͻ 0.05) associated with incident diabetes after adjustment for demographics and weight change (hazard ratio for lifestyle and metformin arms ϭ 1.19 and 1.17 per 10.6 beats/min, respectively). Decreases in heart rate and QT indexes and increases in HRV over time were associated with a lower risk of developing diabetes. The protective association between decreased heart rate and incident diabetes in the lifestyle arm remained significant after accounting for change in weight and physical activity.CONCLUSIONS -Indexes that reflect autonomic function and fitness improved (i.e., heart rate decreased and HRV increased) in the lifestyle modification arm of the DPP. Improvements in these indexes are inversely associated with the development of diabetes independent of weight change. Diabetes Care 29:914 -919, 2006A utonomic impairment has been identified at the time of diabetes diagnosis, which suggests that impairment may be present after a relatively brief exposure to hyperglycemia or develop in conjunction with obesity or insulin resistance (1,2). Cross-sectional studies in adults without diabetes provide evidence that markers of autonomic functioning are inversely associated with obesity, insulin resistance, and fasting glucose (3-6). Recent research suggesting that autonomic dysfunction predicts the development of diabetes (7,8) supports the long-held clinical suspicion that autonomic dysfunction is associated with the development of diabetes in healthy adults (9).Adults were identified as eligible to participate in the Diabetes Prevention Program (DPP) because they were at risk for developing diabetes, most commonly because of existing hyperglycemia and obesity. Thus, it is plausible that many had existing autonomic impairment at baseline in the study. At the conclusion of the trial, there was a significantly lower incidence of diabetes in the intensive lifestyle modification arm compared with that in the metformin or placebo arms (10). Lifestyle modification involved increasing physical activity and lowering dietary fat intake with a goa...

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Methodology of ECG Interpretation in the Dalhousie Program; NOVACODE ECG Classification Procedures for Clinical Trials and Population Health Surveys

Cited by 157 publications

References 23 publications

Why Are Patients With Chronic Obstructive Pulmonary Disease at Increased Risk of Cardiovascular Diseases?

Why Are Patients With Chronic Obstructive Pulmonary Disease at Increased Risk of Cardiovascular Diseases?

Electrocardiographic Predictors of Incident Congestive Heart Failure and All-Cause Mortality in Postmenopausal Women

The Association Among Autonomic Nervous System Function, Incident Diabetes, and Intervention Arm in the Diabetes Prevention Program

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