Association between ventricular repolarization and main cardiovascular risk factors.

OBJECTIVE: To assess the association between QT interval, QT dispersion and main cardiovascular risk factors in Tallinn women population aged 50-69 years. DESIGN: A random sample of Tallinn population, 302 women underwent 12-lead rest ECG, echocardiography and laboratory tests. Corrected QT interval and QT dispersion were calculated. RESULTS: The significant correlation coefficients for corrected QT interval and dispersion were observed with systolic, diastolic, pulse pressure, blood pressure value grade, heart rate, left ventricular mass index, and total cardiovascular risk grade. According to the data of multiple logistic regression, risk factors independently associated with prolonged QTc and QTD were arterial hypertension: OR 2.69, p < 0.001 and OR 3.29, p < 0.001, pulse pressure ≥ 60 mm Hg: OR 2.62, p < 0.001 and OR 3.04, p < 0.001, age > 65 years: OR 2.44, p < 0.001 and OR 1.91, p < 0.01, family history of cardiovascular disease: OR 2.02, p < 0.01 and OR 2.48, p < 0.001, left ventricular hypertrophy: OR 2.78, p < 0.001 and OR 5.29, p < 0.001. Multivariable linear regression data showed an independent association between corrected QT interval, QT dispersion and systolic blood pressure: ß = 0.32, p < 0.001 and ß = 0.39, p=0.003, pulse pressure: ß = 0.21, p = 0.004 and ß = 0.27, p < 0.001, blood pressure value grade: ß = 0.35, p < 0.001 (for QT dispersion only), heart rate: ß = 0.21, p < 0.001 and ß = -0.19, p = 0.001, left ventricular mass index: ß = 0.23, p < 0.001 and ß = 0.27, p < 0.001. CONCLUSION: In Tallinn women population, electrocardiographic parameters reflecting ventricular repolarization are associated with systolic blood pressure, pulse pressure, blood pressure value grade, heart rate and left ventricular hypertrophy.

QT dispersion in relation to left ventricular geometry and hypertension in a population study.

OBJECTIVE: To study the relationship between QT interval dispersion, arterial hypertension and different left ventricular geometric patterns in the framework of a population study. DESIGN: A random sample of the population of Tallinn, 717 men and women aged 35-59, underwent standard 12-lead ECG at rest and echocardiography. Corrected QT dispersion was considered as prolonged when the duration was > or =70 ms. RESULTS: In hypertensives with concentric and eccentric hypertrophy, the mean values of corrected QT dispersion were significantly higher than in those with normal geometry. In the normotensive group no significant differences of the mean values of corrected QT dispersion were found in relation to left ventricular geometry. Mean values of corrected QT dispersion were higher in hypertensives than in normotensives in each left ventricular geometric pattern. Corrected QT dispersion > or =70 ms was mainly associated with concentric hypertrophy. CONCLUSION: Prolonged corrected QT dispersion is associated with left ventricular geometric abnormalities and arterial hypertension and is mostly related to concentric hypertrophy.

Arterial hypertension, left ventricular geometry and QT dispersion in a middle-aged Estonian female population.

The aim of the present study was to determine the prevalence of Left ventricular hypertrophy (LVH) and different left ventricular (LV) geometric patterns in the middle-aged women population of Tallinn, to assess the relationship between LV geometry, age, blood pressure and LV repolarization duration and inhomogeneity. A random sample of the population, 482 women aged 35-59, was examined in the framework of a cardiovascular risk factors survey for the WHO/CINDI programme years 1999-2000. Patients with valvular pathology, primary cardiomyopathy, atrial fibrillation, bundle branch blocks and flat T wave on electrocardiography (ECG) were excluded; 398 (82.2%) of the participants underwent echocardiography (Echo) and standard 12-lead ECG at rest and were included in the study. LVH was defined if left ventricular mass (LVM), LVM/height and LVM/BSA were >198 g, >121 g/m and > 120 g/m2, respectively. Arterial hypertension was determined in 23.1% of the women. The prevalence of arterial hypertension was three times higher in those aged 50-59 than in those aged 40-49 (37.4% vs 13.2%; p < 0.05). Different geometric patterns were found as follows: concentric hypertrophy in 9.1%; eccentric hypertrophy 33.9%; concentric remodelling 9.5% and normal geometry 47.5% of the participants. Concentric hypertrophy was found exclusively in hypertensive women and increased with age. No age-related eccentric hypertrophy and concentric remodelling differences were found, either in the normotensive or in the hypertensive group. Prolonged QT dispersion--a marker of increased myocardial electrical instability, was associated with LVH and arterial hypertension and was related mostly to concentric hypertrophy in hypertensives.

Echocardiographic assessment of the different left ventricular geometric patterns in middle-aged men and women in Tallinn.

The aim of this study was to determine the association of left ventricular (LV) geometry with sex, age, arterial hypertension and obesity in Tallinn. In a framework of a population study for cardiovascular risk factors, echocardiography was carried out in 325 men and 398 women (69.3% of all 1043 participants aged 35-59) in 1999-2001. Left ventricular hypertrophy was defined if left ventricular mass (LVM), LVM/height and LVM/body surface area were 294 g, 163 g/m and 150 g/m2 in men, and 198 g, 121 g/m and 120 g/m2 in women, respectively. LV geometry was analysed according to four types generally recognized (with regard to relative wall thickness > 0.45). The prevalence of concentric hypertrophy was similar in men and women: 7.7% and 9.1%. The prevalence of eccentric hypertrophy was significantly higher in women than in men (33.3% vs 4.9%). Concentric remodelling was also found in women more often than in men (9.5 vs 5.5%; p < 0.05). Regardless of sex and age, concentric hypertrophy was never found in participants with blood pressure < 140/90. In hypertensives, there was a tendency for age-related increase of concentric hypertrophy prevalence: the latter was higher in women than in men: 39.1% vs 25.5%; p < 0.05. In examinees with BMI < 30, this type of LV geometry was seldom found: in 3.1% of men and 5.0% of women; p < 0.05. In obese persons, it increased with age, reaching 26.5% in men and 21.2% in women (p < 0.05). The prevalence of eccentric hypertrophy in men increased with age, and with hypertension and obesity. The prevalence of concentric remodelling in men was not related to BMI; it was significantly more often found in older age groups and in hypertensives. In women, the prevalence of eccentric hypertrophy and concentric remodelling was not related to age, hypertension or obesity.