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P Rautaharju

Publications and source records attributed to P Rautaharju.

18 recordsLinked to original sources
PubMed2001

Standards for the function of an academic 12-lead electrocardiographic core laboratory.

An academic 12-lead electrocardiogram (ECG) core laboratory aims to provide the highest possible quality ECG recording, measurement, and storage to aid clinicians in research into important cardiovascular outcomes and to maximize the credibility of scientific results based solely, or in part, on ECG data. This position paper presents a guide for the structure and function of an academic ECG core laboratory. The key functional aspects are: 1) Data collection, 2) Staff composition, 3) Diagnostic measurement and definition standards, 4) Data management, 5) Academic considerations, 6) Economic consideration, and 7) Accreditation. An ECG Core Laboratory has the responsibility for rapid and accurate analysis and responsible management of the electrocardiographic data in multicenter clinical trials. Academic Laboratories, in addition, provide leadership in research protocol generation and production of research manuscripts for submission to the appropriate peer-review journals.

Accreditation↗
PubMed2000

Relation of systemic blood pressure, left ventricular mass, insulin sensitivity, and coronary artery disease to QT interval duration in nondiabetic and type 2 diabetic subjects.

A prolonged QT interval has been identified as a risk factor for cardiovascular disease; however, knowledge about etiologic factors is limited. We studied determinants of QT interval duration in the Insulin Resistance Atherosclerosis Study, a large, triethnic population (n = 1,577) with varying degrees of glucose tolerance. In particular, we sought to investigate the relation of QT interval with blood pressure (BP), left ventricular (LV) mass, estimated using electrocardiographic criteria, and insulin sensitivity, directly measured by a frequently sampled intravenous glucose tolerance test. QT interval was measured electronically on electrocardiograms at rest and corrected for heart rate using standard equations. The QT interval was related to various components of the insulin resistance syndrome, including BP and insulin sensitivity. Multivariate analyses showed that BP and LV mass were the main determinants of the QT interval in diabetic and nondiabetic subjects. Additionally, prevalent coronary artery disease was related to the QT interval in subjects with newly diagnosed diabetes. In conclusion, we found that BP and LV mass were the strongest and most consistent determinants of the QT interval in nondiabetic and diabetic subjects. Additional factors potentially contributing to QT interval prolongation in diabetic patients include insulin sensitivity and prevalent coronary artery disease.

Analysis of Variance↗
PubMed1999

Is QT interval a marker of subclinical atherosclerosis in nondiabetic subjects? The Insulin Resistance Atherosclerosis Study (IRAS).

BACKGROUND AND PURPOSE: We studied the relationship of heart rate-corrected QT interval with subclinical atherosclerosis, as determined by ultrasonographic measurement of carotid intima-media thickness (IMT) in nondiabetic subjects in the Insulin Resistance Atherosclerosis Study (IRAS). Prolonged heart rate-corrected QT interval is an unfavorable prognostic factor of cardiovascular morbidity and mortality, and QT interval prolongation may be the result of atherosclerosis. METHODS: B-mode ultrasound imaging of the carotid artery IMT was performed in a large, triethnic, nondiabetic population free of clinical coronary artery disease (n=912). QT interval was measured on resting electrocardiograms with use of a computer program and corrected for heart rate with standard equations. RESULTS: IMT of the common carotid artery correlated significantly with heart rate-corrected QT interval duration (r=0.15 for QT(60) and r=0.14 for QTc), whereas no relationship between IMT of the internal carotid artery and QT interval was found (r=-0.01). The association was somewhat stronger in women than in men. In a multiple regression analysis adjusting for demographic variables, the association of common carotid artery IMT to heart rate-corrected QT interval remained highly significant, but adjustment for cardiovascular risk factors weakened the relationship. CONCLUSIONS: We found a significant relation of heart rate-corrected QT interval to carotid atherosclerosis in nondiabetic subjects that was stronger in women and partly mediated by cardiovascular risk factors, including hypertension. QT interval may therefore serve as a marker for clinically undetected ("subclinical") atherosclerotic disease.

Arteriosclerosis↗
PubMed1999

Right bundle branch block as a cause of false-negative ECG classification of inferior myocardial infarction.

It is generally accepted in clinical electrocardiography that a right bundle branch block (RBBB) does not interfere with the electrocardiographic (ECG) diagnosis of myocardial infarction (MI). The basic assumption is that the initial excitation wavefronts are relatively unchanged in RBBB. This study compared serial changes in Q wave duration in inferior leads II, III, and aVF in 9 patients who developed RBBB within 3 weeks after myocardial revascularization procedure (RBBB group) and in 41 revascularized patients without RBBB in the same observation period (control group). Q wave durations in the electrocardiograms obtained before the patients' procedures were not significantly different between the study and control groups. However, Q wave durations shortened significantly more in the RBBB group than in the control group. The most pronounced Q wave duration shortening took place in lead aVF, -18.2 ms in the RBBB group versus -3.8 ms in the control group (P = .0001). The shortening was less pronounced, although significant, in leads II and III: II, -7.6 +/- -10.9 ms in the RBBB group vs -2.3 +/- -3.5 ms in the control group (P = .01); III, -11.3 +/- -10.5 ms vs -2.6 +/- -6.5 ms (P = .002); aVF, -18.2 +/- -13.5 ms vs -3.8 +/- -5.3 ms (P < .0001). It is concluded that incident RBBB complicating revascularization procedures may cause significant alterations in spatial orientation of the initial excitation wavefronts. This may be a potential source of false-negative ECG diagnosis of inferior MI, particularly in clinical trials where serial ECG analysis is an important part in MI classification.

Bundle-Branch Block↗
PubMed1998

Comparison of the Heart and Estrogen/Progestin Replacement Study (HERS) cohort with women with coronary disease from the National Health and Nutrition Examination Survey III (NHANES III)

BACKGROUND: The Heart and Estrogen/Progestin Replacement Study (HERS) is the first large clinical trial designed to test the efficacy of postmenopausal estrogen/progestin therapy for secondary prevention of coronary heart disease (CHD). To examine the representativeness of the HERS cohort to the general population of postmenopausal women with CHD, we compared the baseline cardiovascular risk factor data from HERS with similar data from women presumed to have CHD from the National Health and Nutrition Examination Survey (NHANES) III. METHODS: Age, race, and cardiovascular disease risk factors were compared in the 2763 postmenopausal women younger than 80 years old, with a uterus, and with documented CHD in HERS versus 145 similarly aged women with clinical or electrocardiographic evidence of CHD from phase I of NHANES III. RESULTS: There were fewer current smokers in HERS (13%) than in the NHANES cohort (21.7%, p = 0.05). Similarly, a history of hypertension was less prevalent in HERS (58.6%) than in the NHANES cohort (69.3%, p = 0.03). Women with fasting triglyceride levels >3.39 mmol/L or fasting glucose levels >16.6 mmol/L were excluded from HERS, resulting in fewer diabetics (22.9% vs 29.5%, p = 0.26) and lower serum triglyceride levels (1.88 mmol/L vs 2.25 mmol/L, p = 0.19) in HERS versus the NHANES cohort. Systolic and diastolic blood pressure, body mass index, physical activity, and total LDL and HDL cholesterol were not significantly different between the two groups. CONCLUSIONS: The HERS cohort had fewer CHD risk factors than women with myocardial infarction or angina in NHANES III, although comparison is hindered by differences in selection criteria. The many women with diabetes and hypertriglyceridemia in the NHANES cohort emphasizes the importance of testing strategies for secondary prevention of CHD in this high-risk subgroup.

Aged↗
PubMed1997

Cardiac autonomic function and incident coronary heart disease: a population-based case-cohort study. The ARIC Study. Atherosclerosis Risk in Communities Study.

Cardiac autonomic activity, as assessed by heart rate variability, has been found to be associated with postmyocardial infarction mortality, sudden death, and all-cause mortality. However, the association of heart rate variability and the incidence of coronary heart disease (CHD) is not well described. The authors report on the association of baseline cardiac autonomic activity (1987-1989) with incident CHD after 3 years (1990-1992) of follow-up of the Atherosclerosis Risk in Communities Study cohort selected from four study centers in the United States by using a case-cohort design. The authors examined 137 incident cases of CHD and a stratified random sample of 2,252 examinees free of CHD at baseline. Baseline, supine, resting beat-to-beat heart rate data were collected. High- (0.16-0.35 Hz) and low- (0.025-0.15 Hz) frequency spectral powers and high-/low-frequency power ratio, estimated from spectral analysis, and standard deviation of all normal R-R intervals, calculated from time domain analysis, were used as the conventional indices of cardiac parasympathetic, sympatho-parasympathetic, and their balance, respectively. Incident CHD was defined as hospitalized myocardial infarction, fatal CHD, or cardiac revascularization procedures during 3 years of follow-up. The age, race, gender, and other CHD risk factor-adjusted relative risks (and 95% confidence intervals) of incident CHD comparing the lowest quartile with the upper three quartiles of high-frequency power, low-frequency power, high-/low-frequency power ratio, and standard deviation of R-R intervals were 1.72 (95% confidence interval (CI) 1.17-2.51), 1.09 (95% CI 0.72-1.64), 1.25 (95% CI 0.84-1.86), and 1.39 (95% CI 0.94-2.04), respectively. The findings from this population-based, prospective study suggest that altered cardiac autonomic activity, especially lower parasympathetic activity, is associated with the risk of developing CHD.

Case-Control Studies↗
PubMed1996

Clinically silent electrocardiographic abnormalities and risk of primary cardiac arrest among hypertensive patients.

BACKGROUND: Whether continuous ECG indexes that reflect the severity of left ventricular hypertrophy (LVHI), myocardial injury (CIIS), and QT-interval prolongation (QTI) are associated with the risk of primary cardiac arrest among hypertensive patients, independent of conventional binary ECG criteria, remains unknown. METHODS AND RESULTS: We conducted a population-based case-control study among patients who were free of clinically recognized heart disease and who received care at a health maintenance organization. Cases (n = 131) were treated hypertensive patients who had had a primary cardiac arrest between 1977 and 1990. Controls (n = 562) were a stratified random sample of treated hypertensive patients. Resting ECGs were reviewed to estimate the severity of left ventricular hypertrophy, myocardial injury, and QT-interval prolongation on the basis of the algorithms of the Novacode ECG classification system. After adjustment for other risk factors and binary ECG criteria for the abnormalities, the LVHI, CIIS, and QTI scores were directly related to the risk of primary cardiac arrest. In a comparison of the 80th with the 20th percentile score for the LVHI, the risk was increased 40% (odds ratio, 1.4; 95% CI, 1.0 to 2.0); for the CIIS, the risk was increased 70% (odds ratio, 1.7; 95% CI, 1.2 to 2.5); and for the QTI, the risk was increased 80% (odds ratio, 1.8; 95% CI, 1.3 to 2.7). CONCLUSIONS: Our findings suggest that continuous ECG indexes that reflect left ventricular hypertrophy, myocardial injury, and QT-interval prolongation are directly related to the risk of primary cardiac arrest among hypertensive patients without clinically recognized heart disease. Binary ECG criteria may underestimate the prognostic importance of these pathophysiological abnormalities.

Adult↗
PubMed1996

Association of cardiac autonomic function and the development of hypertension: the ARIC study.

To relate cardiac autonomic function measured by heart rate variability (HRV) with prevalent and incident hypertension at the population level, the authors examined a stratified random sample of 2,061 examinees from the biracial Atherosclerosis Risk in Communities (ARIC) cohort. Baseline, supine, resting beat-to-beat heart rate data were collected. High frequency (HF, 0.15 to 0.35 Hz), low frequency (LF, 0.025 to 0.15 Hz) spectral powers, and LF/HF ratio, estimated from spectral analysis, and standard deviation of all normal RR intervals (SDNN), calculated from time domain analysis, were used as the conventional indices of cardiac autonomic function. From this sample, 650 prevalent hypertensives were identified. Of those normotensive at baseline (n = 1,338), 64 participants developed hypertension during 3 years of follow-up. In the cross-sectional analysis, the adjusted geometric means of HF were 1.26, 1.20, and 1.00 (beat/min)2 for normotensives, untreated hypertensives, and treated hypertensives, respectively; means of LF were 3.24, 3.26, and 2.58; means of LF/HF ratio were 2.57, 2.70, and 2.56; and means of SDNN were 39, 34, and 35 (ms) respectively. In the prospective analysis, a statistically significant, graded inverse association between baseline HF and the risk of incident hypertension was observed: the adjusted incident odds ratios (95% CI) were 1.00, 1.46 (0.61, 3.46), 1.50 (0.65, 3.50) and 2.44 (1.15, 5.20) from the highest to the lowest quartile of HF. No clear pattern of association was observed for LF. Significant trends of association for LF/HF and SDNN and incident hypertension were also found. These results suggest that cardiac autonomic function is associated with prevalent hypertension, and that reduced vagal function and the imbalance of sympatho-vagal function are associated with the risk of developing hypertension.

Adult↗
PubMed1995

Relation between electrocardiography and echocardiography for left ventricular mass in mild systemic hypertension (results from Treatment of Mild Hypertension Study).

Clinical recognition of hypertensive cardiac involvement depends primarily on use of noninvasive methods. The performance of 8 electrocardiographic (ECG) criteria sets were compared with an echocardiographic standard in the treatment of Mild Hypertension Study. Electrocardiograms were computer processed to define the following ECG criteria sets: (1) Casale/Devereux, (2) Cornell product, (3) Cornell voltage, (4) 12-lead voltage product, (5) sum of 12-lead voltage, (6) Rautaharju, (7) Sokolow-Lyon, and (8) Romhilt-Estes. Echocardiographic left ventricular (LV) mass index was calculated by using the Penn convention on a biracial population of 834 men and women. Correlations between ECG and echocardiographic LV mass index were modest (<0.40). ECG-LV hypertrophy sensitivity at 95% specificity was < 34%. The Casale/Devereux ECG criteria showed the highest average sensitivity (17%) at 95% specificity for all race-sex groups. Whites had significantly higher correlation values than blacks. ECG correlations with LV mass index were consistently improved by including systolic blood pressure and body mass index. ECG criteria sets appear to be optimized for white men. The study findings confirm the poor ECG sensitivity and correlation with echocardiographic LV mass and suggest: (1) further refinement of ECG criteria alone in white men is unlikely to improve its relationship with LV mass; and (2) combining the electrocardiogram with other non-ECG variables or noninvasive measurements offers the best strategy for improving ECG sensitivity and its prognostic value.

Aged↗
PubMed1994

Black-white differences in electrocardiographic left ventricular mass and its association with blood pressure (the ARIC study). Atherosclerosis Risk in Communities.

Black-white differences in the association between antihypertensive therapy, continuous measures of mean arterial and pulse pressures and left ventricular (LV) mass estimated from a multivariable electrocardiographic algorithm were examined in 6,020 men (23% black) and 7,970 women (29% black) participating in the Atherosclerosis Risk in Communities (ARIC) study. Mean arterial and pulse pressures, weight, the percentage of subjects taking antihypertensive medication, and LV mass were higher in black than in white men (98 vs 89 mm Hg, 47 vs 46 mm Hg, 188 vs 187 pounds, 30% vs 17%, and 243 vs 217 g, respectively). Results of similar direction but greater magnitude were observed in black versus white women (mean arterial pressure, 94 vs 85 mm Hg; pulse pressure, 50 vs 47 mm Hg; weight, 180 vs 153 pounds; percent treated, 42% vs 18%; and LV mass, 203 vs 169 g, respectively). In multivariable regression analyses, blacks had higher levels of LV mass, and LV mass increased more sharply with increasing mean arterial pressure in blacks than in whites after adjusting for age, pulse pressure, and weight. At equal mean arterial and pulse pressures, age, and weight, treated blacks had higher LV mass than treated whites. These data indicate that blacks have higher LV mass than whites, and a more pronounced blood pressure-LV mass relation after controlling for other risk factors and treatment status. Given the prognostic importance of LV hypertrophy,

Antihypertensive Agents↗
PubMed1989

Electrocardiographic left ventricular hypertrophy and effects of antihypertensive drug therapy in hypertensive participants in the Multiple Risk Factor Intervention Trial.

Data are reported on electrocardiographic left ventricular hypertrophy (ECG LVH) among 8,012 men classified as hypertensive at baseline in the Multiple Risk Factor Intervention Trial. Compared with those allocated to the usual care (UC) control group, men allocated to the special intervention (SI) group experienced a mean reduction of 4 mm Hg in diastolic blood pressure and 7 mm Hg in systolic blood pressure, over 6 years of follow-up. There were 378 new cases of ECG LVH during follow-up; the incidence in the SI group was about 23% less than that in the UC group (4.2 vs 5.4% 2P less than 0.01). Among the 189 men with ECG LVH at baseline, those in the SI group experienced about 24% more annual follow-up visits at which they were free of ECG LVH (4.6 vs 3.7 visits; 2P less than 0.01). This reduced incidence and increased reversal of ECG LVH in the SI group compared with that in the UC group was consistent with significant overall reductions (2P less than 0.001) among SI men in mean wave amplitude in those leads in which voltage is correlated with left ventricular mass (T wave in V1, R wave in aVL and S wave in V3). In SI and UC groups combined, the presence of ECG LVH either at baseline or at follow-up was associated with several-fold increases in death from cardiovascular diseases in general, and death from coronary artery disease in particular.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

On sudden death.

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Death, Sudden↗
PubMed1976

Body position, electrode level, and respiration effects on the Frank lead electrocardiogram.

Frank lead ECG/VCG changes with deep inspiration, expiration, and body position were investigated in 194 patients, 100 with an old myocardial infarction and the remaining 94 chosen as a representative sample of catheterization laboratory patients with a variety of cardiac conditions. In a subgroup of 144 of the patients, Frank lead records were made both at the fifth and the fourth intercostal space. Diagnostic interpretation was performed using the VA-Pipberger ECG Program. The results indicate that, in general, body position and electrode level influence on mean intervals and orientation angles is negligible. There was a highly significant decrease in the R and Q wave amplitudes in leads X and Z and in the maximum spatial magnitude of QRS when electrodes were shifted from the fifth to the fourth interspace. The most pronounced decrease in ECG/VCG amplitudes took place in deep inspiration while mean orientation angles changed little, with the exception of QRS elevation. However, while mean changes with body position and electrode level were rather small, substantial orientation and magnitude changes took place in many patients. Diagnostic interpretation of the records changed in 12.5% with electrode level change, in 11.9% with the transition of body position, and in 16.8% with deep inspiration. Strict standardization of electrode positions and recording procedure is suggested, particularly when serial comparison of Frank lead records is planned.

Adolescent↗