ABSTRACT
Objective: The present study was undertaken to investigate the prognostic value of the frontal planar QRS-T angle in patients without angiographically apparent coronary atherosclerosis
Subjects and Methods: Three hundred and seven patients with normal coronary arteries on coronary angiography were included. The absolute difference between the frontal QRS- and T-wave axes was defined as the frontal planar QRS-T angle, and patients were divided into 3 subgroups based on the frontal planar QRS-T angle [<45, 45-90, and >90]. Demographic, clinical, laboratory, and angiographic data were compared between groups. Based on the regression analysis results, patients were recategorized into 4 groups according to their luminal calibers of left main coronary artery [LMCA] and history of hypertension [HT] [nonhypertensive LMCA 4.13 mm, hypertensive LMCA 4.13 mm]
Results: The median value of the frontal planar QRS-T angle of all participants was 38°. Subjects with the widest frontal planar QRS-T angle were older [p = 0.027], were hypertensive [p = 0.001], and had higher corrected QT values [p = 0.001]. Patients with the widest frontal planar QRS-T angle had larger LMCA and left anterior descending coronary artery diameters compared to subjects with a normal and borderline frontal QRS-T angle [p = 0.004 and p = 0.028, respectively]. Corrected QT, HT, and LMCA diameter were found as independent predictors of the frontal planar QRS-T angle. Subjects with HT and a larger luminal caliber of LMCA had the widest frontal planar QRS-T angle
Conclusion: Patients with a history of HT and a larger luminal caliber of LMCA had the widest frontal planar QRS-T angle. Since HT-induced electrophysiological changes are still not well established and we observed that changes in the luminal caliber of coronary arteries are associated with an abnormal frontal QRS-T angle, the frontal QRS-T angle could serve as a marker of ventricular repolarization heterogeneity in hypertensive patients in addition to keeping track of arrhythmic events, even before overt disease
ABSTRACT
We aimed to examine the relationship between serum uric acid levels and left atrial appendage [LAA] peak flow velocity, an indicator of the mechanical functions of the LAA, and atrial fibrillation [AF]. Transesophageal echocardiography was performed before cardioversion in 153 patients with AF. The patients were categorized into 2 groups based on their LAA blood flow velocity. Group 1 included 87 patients with a low LAA flow velocity [<35 cm/s], and group 2 comprised 66 patients with a normal LAA flow velocity [>/=35 cm/s]. The chi[2]and Student's t tests were used to compare categorical and quantitative data between the groups. Linear regression analyses were performed to demonstrate the independent association between serum uric acid levels and LAA peak flow velocity. The LAA blood flow velocity was 24.62 +/- 5.90 cm/s in group 1 and 49.28 +/- 13.72 cm/s in group 2, respectively [p < 0.001]. The serum uric acid levels were 6.88 +/- 1.85 mg/dl in group 1 and 5.97 +/- 1.51 mg/dl in group 2, and the difference was statistically significant [p = 0.001]. There was a negative correlation between serum uric acid levels and LAA blood flow velocity [r = -0.216, p = 0.007]. Multivariate regression analysis showed that serum uric acid levels, age and gender differences were significant predictors of the LAA peak flow velocity. High serum uric acid levels were associated with a low contractile function of the LAA and could provide additional prognostic information on future thromboembolic events in patients with AF
Subject(s)
Humans , Male , Female , Middle Aged , Aged , Atrial Appendage , Atrial Fibrillation , Blood Flow Velocity , Atrial Function, Left , Retrospective StudiesABSTRACT
We aimed to evaluate the relationship between estimated glomerular filtration rate [eGFR] and QT dispersion [QTd] in patients with coronary artery disease [CAD]. Sixty patients [mean age 62.72 +/- 12.48 years] included 46 male, [mean age 60.89 +/- 12.70 years] and 14 female [mean age 68.71 +/- 9.86 years] were enrolled in this study. Patients were divided into 2 groups according to their eGFR using the 6 variable MDRD equation. Group 1 consisted of patients with estimated eGFR < 60 ml/min/1.73m[2] and Group 2 consisted of patients with eGFR >/= 60 ml/min/1.73m[2]. Baseline patient characteristics were homogeneous in both groups except for age, gender and smoking. Also, the extent of CAD was similar in both groups [p > 0.05] QTd values were found higher in group 1 than those of group 2 [57.23 +/- 40.65 ms vs. 31.23 +/- 14.47 ms, p = 0.002]. After adjustment for age, gender and smoking using one-way ANCOVA test, statistically significant difference in QTd still existed between the groups [p=0.038]. QTd tends to be higher in patients with poor renal function independent of severity of angiographical CAD. QTd may be a potentially useful non-invasive test in the management of patients with poor renal function, especially those with CAD