Association between ventricular repolarization and main cardiovascular risk factors

Association of major and minor ECG abnormalities with traditional cardiovascular risk factors in the general population: a large scale study

Cardiovascular disease (CVD) can be determined and quantified using the electrocardiogram (ECG) analysis. Identification of the risk factors associated with ECG abnormalities may advise prevention approaches to decrease CVD burden. In this study we aimed to investigate the association between CVD risk factors and minor and major ECG abnormalities in a general Iranian adult population. This study was conducted in 2010 and covered a population of 9035 males and females aged 35 to 65 years recruiting from the phase I of Mashhad Stroke and Heart Atherosclerotic Disorder (MASHAD) cohort study. The participants were drawn by a stratified cluster random sampling technique. The Bivariate and multinomial logistic regression analysis were conducted considering gender stratification to explore the association of ECG abnormalities with traditional cardiovascular risk factors. There was a significant association between minor and major ECG abnormalities and hypertension (HTN), type 2 diabetes (T2DM), smoking, and physical activity (p < 0.005). There was a significant trend, in both genders, for increasing major abnormalities as the number of CVD risk factors increased. But, only in women, the minor abnormalities increase in frequency as the number of CVD risk factors increased. The results of multinomial logistic regression showed that men with HTN [ARRR = 1.25, 95% CI 0.99, 1.57] and T2DM [ARRR = 1.31, 95% CI 0.99, 1.74] had the highest likelihood to have major abnormalities, although these are not statistically significant. For women, those with HTN had the highest likelihood to have major [ARRR = 1.36, 95% CI 1.13, 1.63] and minor [ARRR = 1.35, 95% CI 1.15, 1.58] abnormalities. Also, women aged > 60 years were more likely to have major [ARRR = 2.01, 95% CI 1.49, 2.74] and minor [ARRR = 1.59, 95% CI 1.20, 2.10] abnormalities compared to women aged < 45 years. Age and HTN were significantly associated with major and minor ECG abnormalities in women, and, on the other hand, HTN and T2DM were associated with major abnormalities in men. Taken together, these findings suggest that healthcare providers should advise preventive approaches to the asymptomatic adults with both major and minor electrocardiographic abnormalities that may predict cardiovascular risk.

Associations of increased spatial QRS-T angle with cardiovascular risk factors: data from the regional sample of ESSE-RF study

Aim. To study the associations of increased spatial QRS-T angle (sQRS-Ta ≥90°) with cardiovascular risk factors (RFs).

Material and methods. We analyzed 1411 electrocardiography (ECG) records of men and women aged 25-64 years from a random regional sample of the Epidemiology of Cardiovascular Diseases and their Risk Factors in Regions of Russian Federation (ESSE-RF) study. Relationships of sQRS-Ta with the following RFs were assessed: hypertension (HTN), systolic blood pressure (SBP) ≥140 mm Hg, diastolic BP (DBP) ≥90 mm Hg, pulse pressure (PP) ≥60 mm Hg; glucose ≥7,0 mmol/l, hypercholesterolemia; hypertriglyceridemia; high-density lipoprotein cholesterol (HDL-C) ≤1,0/1,2 mmol/l in men/women, low-density lipoprotein cholesterol (LDL-C) >3,0 mmol/l; C-reactive protein (CRP) >1 mg/L; overweight, obesity and abdominal obesity; heart rate (HR) >80 bpm; age >52 years.

Results. Weak but significant correlations of sQRS-Ta with age (in women), SBP, DBP, PP, body mass index, waist circumference, lipids, glucose, CRP were revealed. Univariate logistic regression demonstrated significant associations of increased sQRS-Ta with HTN, elevated SBP and PP, overweight, obesity and abdominal obesity, hypercholesterolemia, elevated LDL-C and CRP, hyperglycemia, age >52 years and heart rate >80 bpm. There were no associations of increased sQRS-Ta with male sex, elevated DBP, smoking, hypertriglyceridemia, and low HDL-C levels. The sQRS-Ta associations characteristic of women was similar with associations found among the entire sample. Men with increased sQRS-Ta had no associations with any of analyzed RFs. In multivariate models, increased sQRS-Ta was associated with the following combination of RFs: age >52 years, heart rate >80 bpm, HTN, increased PP, overwaight, and male sex. According to direct stepwise selection among all subjects and in women, the main contribution to sQRS-Ta was made by SBP, age, HDL-C and heart rate.

Conclusion. Despite the significance of stepwise regression model (p=0,0001), the low coefficient of determination R2 may indicate other not yet identified determinants with relevant associations with sQRS-Ta.

Electrocardiographic findings in patients with polycythemia vera

BACKGROUND

The 12-lead surface electrocardiogram (ECG) is a useful tool to predict both atrial and ventricular arrhythmias via P-wave and QT measurements and its derivatives. Polycythemia vera (PV) is a chronic myeloproliferative disorder associated with cardiovascular events. The aim of this study was to assess ECG findings of patients with PV.

METHOD AND MATERIALS

Sixty patients with PV (34 male, mean age 58±11 years) and 60 age and gender-matched healthy volunteers were enrolled into the study. From the 12-lead surface ECG, P-wave and both conventional QT measurements and transmyocardial repolarization parameters (T(peak)-T(end) interval (T(p)-T(e)) and derivatives) were evaluated digitally by two experienced cardiologists. In addition, a novel parameter, Pi was calculated digitally as the standard deviation of the P-wave duration across the 12 ECG leads.

RESULTS

QT duration and corrected QT interval were significantly longer in the PV group compared to healthy controls (p<0.01 and p<0.01, respectively). The T(p)-T(e) was longer and the T(p)-T(e)/QT ratio was significantly higher in the PV group compared to the controls. P-wave analyses showed that all P-wave parameters including Pmax, Pmin, P dispersion, and Pi were significantly prolonged in PV patients compared to the controls. The increase of both T(p)-T(e )and P max in the PV group was independent of age, BMI, diabetes and hypertension, gender, systolic blood pressure, hemoglobin, hematocrit, left atrial dimension, left ventricular end-diastolic diameter and early deceleration time in a univariate analysis of co-variance model (F=11.097, p=0.001 and F=31.537, p=0.0001, respectively).

CONCLUSION

The present study demonstrated that PV may be associated with electrocardiographic abnormalities of both atrium and ventricle.