Frontal QRS-T angle is related with hemodynamic significance of coronary artery stenosis in patients with single vessel disease

Relationship between frontal QRS-T duration and the severity of coronary artery disease in who were non-diabetic and had stable angina pectoris

OBJECTIVE

There is a known relationship between frontal-QRS-T (F-QRS-T) angle and coronary artery disease (CAD). This study examined the relationship between F-QRS-T angle changes and CAD severity in patients with stable CAD.

METHODS

A total of 202 patients were included in the study after the implementation of exclusion criteria among 894 patients, who were admitted to the outpatient clinic with stable angina pectoris between September 2018 and September 2019. The F-QRS-T angle calculated on the 12-lead electrocardiograms (ECGs) of the patients (taken in the outpatient clinic), and the CAD severity calculated using the Gensini score in patients undergoing coronary angiography were compared.

RESULTS

Of the patients included in the study, 38.6% were female and 61.4% were male. The mean age was calculated as 60.16±11.27 years, and 52% of the patients had hypertension. There was no difference between the groups in terms of demographic and clinical values. In a comparison of CAD severity and F-QRS-T angles, the F-QRS-T angle was seen to be statistically significantly higher in the severe CAD group [91°° (102/79)] compared to the group with mild CAD [53°° (64/38)]. In the multivariate logistic regression analysis, there was a significant association between the F-QRS-T angle (odds ratio=1.09, 95% confidence interval=1.06-1.11, p<0.001) and CAD severity.

CONCLUSION

It seems that CAD severity in patients who were non-diabetic and had stable angina pectoris is associated with the F-QRS-T angle.

Serum Bilirubin Level Predicts Frontal QRS-T Angle Change in Patients with Acute Coronary Syndrome

Introduction: The predictive role of serum bilirubin levels on the alteration of total ischemic burden expressed via frontal QRS-T angle change has never been studied in patients with acute coronary syndrome (ACS). In this study, we aimed to investigate the relationship between serum bilirubin levels and frontal QRS-T angle change after percutaneous coronary intervention (PCI) in ACS patients.

Methods: Frontal QRS-T angle change was accepted as positive or negative according to whether the value of the baseline frontal QRS-T angle minus the post PCI frontal QRS-T angle is positive or negative. A total of 314 consecutive patients with ACS who underwent PCI were divided into two groups based on their negative frontal QRS-T angle change (n = 152 patients) and positive frontal QRS-T angle change (n = 162 patients).

Results: Multivariate logistic regression analysis showed that the C-reactive protein (CRP) to albumin ratio (CAR) (Odds ratio [OR]: 0.519, 95% CI: 0.373–0.724, p <0.001), total bilirubin (OR: 3.687, 95% CI: 1.151–8.095, p = 0.03), and low-density lipoprotein (LDL) (OR: 0.985, 95% CI: 0.970–1.000, p = 0.04) were independent predictors of positive QRS-T angle change. In receiver operating characteristics curve analysis, a cut-off value of 0.59 total bilirubin had a 69% sensitivity and a 65% specificity (area under curve: 0.739, p <0.001) for the prediction of positive QRS-T angle change.

Conclusion: In ACS patients, serum total bilirubin has been found to be a useful decision-making tool to predict positive frontal QRS-T angle change as a sign of reduced total ischemic burden, to assess early invasive strategy independently from other study parameters.

[Diagnostic and prognostic significance of QRS-T angle]

The angle between theQRSandTvectors reflects the consistency or inconsistency of the processes of de- and repolarization of the ventricles of the heart and is considered one of the indicators of global electrical heterogeneity of myocardium. In recent years, the prognostic value of theQRS-Tangle has been demonstrated in relation to total and cardiovascular mortality, both in the population and in various groups of patients. The mechanisms of this phenomenon are not completely clear. The review analyses studies published over the past five years on the relationship between theQRS-Tangle and mortality, as well as coronary heart disease and heart failure. Possible mechanisms for increasing theQRS-Tangle are discussed. Data are given on the use of theQRS-Tangle in diagnostic and prognostic scales, including in combination with other indicators of global electrical heterogeneity of myocardium.

Effect of anemia on the frontal QRS-T angle

BACKGROUND

Anemia is a common health problem worldwide and is associated with a poor prognosis for cardiovascular diseases. It can alter myocardial depolarization and repolarization by affecting the generation and propagation of electrical impulses. The frontal QRS-T angle is a novel marker of the absolute difference between myocardial depolarization and repolarization. This study investigated the effects of anemia on the frontal QRS-T angle.

METHODS

The study included 66 anemic subjects with no cardiac disorders, and 50 age- and gender-matched controls. Twelve-lead electrocardiography (ECG) was obtained for all subjects, and the frontal QRS-T angle was calculated based on the automatic report of the ECG machine.

RESULTS

Subjects with anemia had a significantly higher frontal QRS-T angle than subjects without anemia (28.9±14.1 vs. 22.5±11.8, P=0.011). In correlation analysis, the frontal QRS-T angle was positively correlated with the Body Mass Index (BMI; r=0.287, P=0.002), left ventricular mass (LVM; r=0.264, P=0.004), and heart rate (r=0.275, P=0.003) and negatively correlated with the hemoglobin level (r=-0.349, P<0.001). Multivariate regression analysis showed that the hemoglobin level (β=-0.254, tβ=-2.805, P=0.006), BMI (β=0.240, t=2.770, P=0.007), and LVM (β=0.201, t=2.303, P=0.023) were independently associated with the frontal QRS-T angle.

CONCLUSIONS

The hemoglobin level was found to be an independent predictor of the frontal QRS-T angle.