The Value of Frontal Planar QRS-T Angle in Patients without Angiographically Apparent Atherosclerosis

Demonstration of subclinical left ventricular electrical and mechanical dysfunction in overweight subjects by frontal QRS-T angle and 3D-speckle tracking echocardiography

BACKGROUND

Overweightness is a considerable step in the process leading to obesity. There are no sufficient studies on the effect of cardiomyopathy defined in obese patients about overweight subjects. We thought that it may be useful to examine the myocardial involvement in overweight individuals electro-mechanically with more sensitive techniques before the development of obesity cardiomyopathy.

AIM

The aim of the present study was to demonstrate whether or not there are subclinical left ventricular (LV) electrical and mechanical dysfunctions in overweight patients using frontal QRS-T (fQRS-T) angle (electrically) and 3D-speckle tracking echocardiography (mechanically).

METHODS

A total of 80 overweight patients and 80 age- and sex-matched normal weight individuals were enrolled into the study. 3D-STE examinations of the patients were performed. Electrocardiographic recordings were obtained for fQRS-T angle assessment.

RESULTS

The LV-GLS and LV-GCS were significantly depressed in the overweight group than in the normal weight group (-14.5 ± 3.4 vs. -21.7 ± 3.6, p < .001; -15.2 ± 4.6 vs. -24.3 ± 4.8, p < .001, respectively). The fQRS-T angle was found to be increased in the overweight group (142.5 ± 39.2 vs. 114.7 ± 43.5, p = < .001). Statistically significant positive linear correlations were observed between BMI with LV-GLS, LV-GCS, and fQRS-T angle. LV-GLS and LV-GCS were found to be disrupted linearly as BMI increased (r = .718 for BMI and LV-GLS, r = .653 for BMI and LV-GCS). As BMI increased, it was found that the fQRS-T angle increased (r = .692 for BMI and fQRS-T angle).

CONCLUSION

Our results support that, overweight individuals, despite their being apparently healthy, may have subclinical LV myocardial mechanical and electrical dysfunction.

Evaluation of frontal QRS-T angle values in electrocardiography in patients with chronic rhinosinusitis

BACKGROUND

Chronic Rhinosinusitis (CRS) refers to inflammation of the paranasal sinuses and nasal mucosa. Electrocardiographic indicators of ventricular repolarization have been shown to correlate with systemic inflammation parameters. Recently, the frontal QRS-T (fQRS-T) angle has been accepted as a new indicator of ventricular depolarization and repolarization heterogeneity. The (fQRS-T) angle is recommended in predicting the risk of malignant ventricular arrhythmia. In this study, we aimed to evaluate the ventricular arrhythmia potential in patients with chronic rhinosinusitis by examining the relationship between fQRS-T angle on ECG and inflammation markers.

METHODS

Inflammatory markers as well as electrocardiographc (ECG) f(QRS-T) angle, QRS duration, QT interval and corrected QT interval were examined in 54 patients with CRS versus 56 healthy control subjects.

RESULTS

The f(QRS-T) angle was significantly higher in CRS patients than in healthy controls (p < .001). The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and monocyte-to-lymphocyte ratio (MLR) were significantly higher in CRS patients compared to healthy controls (p < .001, for all). Based on correlation analysis, NLR and f(QRS-T) angles were highly correlated (r = .845, p < .001), and according to the results of linear regression analysis, NLR was independently associated with the f(QRS-T) angle (t = 5.149, Beta = 0.595, p = < 0.001).

CONCLUSION

Both f(QRS-T) angle and NLR are significantly increased in CRS patients compared to healthy controls, with increases in NLR also independently associating with increases in f(QRS-T) angle. While the increases in f(QRS-T) angle did not result in clinically alarming absolute values for f(QRS-T), CRS patients might nonetheless be at relatively higher risk for malignant cardiac arrhythmias.

The effect of coronary slow flow on ventricular repolarization parameters

INTRODUCTION

Ischemia due to microvascular dysfunction may be responsible for the heterogeneity of ventricular repolarization in coronary slow flow. To our knowledge, there is no study in which QT interval, Tp-Te interval, index of cardiac-electrophysiological balance (iCEB), and frontal QRS-T angle were evaluated together in patients with CSF. In this study, we examined for the first time the relationship between all these myocardial repolarization parameters and CSF.

MATERIALS AND METHODS

The study group included 178 patients (99 female, mean age: 50.6 ± 8.6 years) with isolated CSF without stenotic lesions and with angiographically proven normal coronary arteries. The control group included 120 patients (71 female, mean age: 49.3 ± 9.4 years) with normal coronary angiography. QRS duration, QT interval, QTc interval, Tp-Te interval, Tp-Te/QT, Tp- Te/QTc, iCEB score, and frontal QRS-T angle were calculated from 12‑lead ECGs.

RESULTS

There was no significant difference in demographic parameters between the two groups. Compared with the control group, patients with CSF had significantly longer QTmax duration, QT dispersion, Tp-Te interval, and higher iCEB score, wider frontal QRS-T angle.

CONCLUSION

In our study, we found that many of the ventricular repolarization parameters were adversely affected in patients with CSF. Impaired parameters may be associated with the risk of malignant ventricular arrhythmias.

Impact of blood pressure lowering on ventricular repolarization heterogeneity in patients with newly diagnosed hypertension

OBJECTIVE

Frontal plane QRS-T (fQRS-T) angle is a marker of ventricular repolarization heterogeneity and increased fQRS-T angle is associated with arrhythmias, adverse events and mortality. However, little is known about the importance and usefulness of fQRS-T angle in hypertensive patients. The present study aimed to investigate the association between blood pressure (BP) levels and fQRS-T angle. The main goal was to demonstrate whether BP lowering has a favorable effect on fQRS-T angle in hypertensive patients.

METHODS

This study included 392 newly diagnosed hypertensive patients who underwent antihypertensive therapy. Responders and nonresponders to antihypertensive therapy were compared regarding baseline and post-treatment fQRS-T angle. fQRS-T angle was calculated as the absolute difference between QRS and T wave axes that were obtained from electrocardiography. Response to treatment was defined as achieving BP levels <140/90 mmHg.

RESULTS

At the 1-month follow-up visit, responders had significantly lower fQRS-T angle compared to nonresponders despite the similar baseline fQRS-T angle (baseline: 57° ± 18.2° vs.56.6° ± 16.3°; P = 0.819, at 1 month: 36.9° ± 13.7 vs.53.5° ± 15.6°; P < 0.001). Moreover, after 3 months of antihypertensive treatment, both responders at 1 month and 3 months had significantly lower fQRS-T angle compared to nonresponders (34.8° ± 13.3° vs. 35.4° ± 12.9° vs. 52.3° ± 13.9°; P < 0.001). Furthermore, a significant moderate positive correlation was observed between systolic BP and fQRS-T angle (r:0.797; P < 0.001), and between diastolic BP and fQRS-T angle (r:0.761; P < 0.001).

CONCLUSION

In the present study, a significant decrease in fQRS-T angle was observed following BP lowering throughout the study period. Therefore, fQRS-T angle may be useful in the monitoring of antihypertensive treatment.

The relationship between frontal QRS-T angle and the severity of newly diagnosed chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterised by persistent airflow restriction and respiratory symptoms. Studies demonstrated that cardiac arrhythmias and cardiovascular mortality increased in these patients as a result of altered myocardial repolarization. Frontal QRS-T angle is a novel marker of myocardial depolarization and repolarization heterogeneity. In this study, we aimed to investigate the relationship between frontal QRS-T angle and disease severity in patients with newly diagnosed COPD.

METHODS

A total of 104 newly diagnosed COPD patients were included in this study. Patients were divided into two groups according to GOLD (Global Obstructive Lung Disease) stage as follows: patients with mild and moderate COPD (group I), and severe and very severe COPD (group II). Frontal QRS-T angle was calculated from the automatic report of the electrocardiography device.

RESULTS

Frontal QRS-T angle was significantly higher in group II patients compared with in group I patients (43.0 [25.5-60.0] vs. 20.0 [12.0-32.0], P < .001). The best cut-off value of frontal QRS-T angle for predicting severe-very severe COPD was ≥34.5°. Correlation analysis showed that frontal QRS-T angle was negatively correlated with FEV1/FVC (r = -.524, P < .001) and MEF25-75 (r = -.453, P < .001). Multivariate logistic regression analysis was showed that frontal QRS-T angle was the only independent predictor of severe-very severe COPD (OR: 1.051, 95% CI: 1.024-1.079, P < .001).

CONCLUSIONS

Frontal QRS-T angle is an easily obtainable marker form surface electrocardiography. In this study, we have shown for the first time that frontal QRS-T angle was significantly increased in patients with severe and very severe COPD.

The relationship between coronary slow-flow and frontal QRS-T angle

OBJECTIVE

It is known that increased frontal QRS-T angle, which is a new ventricular repolarization marker is associated with adverse cardiac outcomes. It has been observed that the coronary slow-flow (CSF) phenomenon can cause arrhythmias and sudden cardiac death. The aim of our study is to investigate the relationship between CSF in patients and the frontal QRS-T angle.

MATERIAL AND METHOD

A total of 200 patients, 97 of who had CSF and 103 with the normal coronary flow (NCF), were included in our study. The CSF group was divided into two groups; single-vessel CSF and multi-vessel CSF. The TIMI-frame count was calculated from the coronary angiography images of each patient. 12-lead electrocardiography (ECG) records were examined. The frontal QRS-T angle was obtained from the automated reports of the ECG device.

RESULTS

The mean age of the study population was 50.7 ± 9.5 and 102 (51%) of patients were female. The frontal QRS-T angle was significantly higher in patients with CSF compared to the NCF group [48(31-64) vs 37(25-46), p = 0.001]. A positive correlation was observed between the frontal QRS-T angle and TIMI-frame count in the correlation analysis performed separately for LAD, Cx, RCA patients with CSF (respectively; r = 0.340 and p < 0.001, r = 0.262 and p = 0.002, r = 0.247 and p = 0.003). The frontal QRS-T angle was higher in patients with multi-vessel CSF than in patients with single-vessel CSF [53.5(41.5-76.5) vs 43.0(23.5-60.5), p = 0.039].

CONCLUSION

There is a positive correlation between frontal QRS-T angle and TIMI-frame count. The frontal QRS-T angle is higher in patients with CSF. Also, frontal QRS-T angle was higher in the multi-vessel CSF group.

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.

Frontal QRS-T angle predicts syntax score in patients with non-ST elevation myocardial infarction

BACKGROUND

Early risk stratification based on SYNTAX score plays a crucial role to identify the need for early invasive strategy in patients with NSTEMI. The predictive role of frontal QRS-T angle [f(QRS-T)] on the atherosclerotic burden of CAD is less clear in NSTEMI patients. In this study, we aimed to investigate the relationship between f(QRS-T) and SYNTAX score in NSTEMI patients.

METHODS

A total of consecutive 269 patients with the diagnosis of NSTEMI transferred to coronary care unit were included in the study. f(QRS-T) was calculated as the absolute value of the difference between the frontal plane QRS and T axes based on automatic report of ECG machine. Syntax score was computed using an online SYNTAX score calculator by well-experienced two cardiologists blinded to the study data. The study population was divided into two groups based on the SYNTAX score low SYNTAX score (≤23), and high SYNTAX score (>23).

RESULTS

Left ventricle ejection fraction (LVEF) (p = 0.001), hemoglobin (p = 0.03) and HDL-C (p = 0.04) levels were lower in the intermediate-high SYNTAX group. Age (72.1 ± 12.5 vs. 64.6 ± 9.4 respectively; p < 0.001), LAD as infarct-related artery 30 (%65.2) vs. 50 (%29.1) respectively; (p = 0.001), f(QRS-T) (100.5 ± 55.3 vs. 65.1 ± 53.1 respectively p = 0.006), troponin I peak (p = 0.06) were higher among patients with intermediate-high Syntax score. In receiver-operating characteristic (ROC) curve analysis, the value for f(QRS-T) to detect syntax score ≥ 23 with a sensitivity of 77% and specificity of 63% was 73,5° in NSTEMI patients(AUC = 0.69). Univariate logistic regression analysis identified that age, LVEF, HDL-C, hemoglobin, infarct-related artery, f(QRS-T) were significantly associated with SYNTAX score. Multivariate logistic regression analysis showed that age (OR: 1.135, 95% CI: 1.039-1.153, p = 0.045), infarct related artery-LAD (OR: 2.897, 95% CI: 1.023-8.209, p = 0.001) and f(QRS-T) (OR: 3.587, 95% CI: 1.093-11.772, p = 0.001) were the independent predictors of SYNTAX score.

CONCLUSION

In NSTEMI patients, f(QRS-T) has been found to be a useful decision-making tool to predict SYNTAX score to assess early invasive strategy.

The role of baseline and post-procedural frontal plane QRS-T angles for cardiac risk assessment in patients with acute STEMI

BACKGROUND

To our knowledge, no study so far investigated the importance of post-procedural frontal QRS-T angle f(QRS-T) in ST segment elevation myocardial infarction (STEMI). The aim of our study was to investigate the role of baseline and post-procedural f(QRS-T) angles for determining high risk STEMI patients, and the success of reperfusion.

METHODS

A total of 248 patients with first acute STEMI that underwent primary percutaneous coronary intervention (pPCI) or thrombolytic therapy (TT) between 2013 and 2014 were included in this study. Baseline f(QRS-T) angle was defined as the angle which measured from the first ECG at the time of hospital admission. Post-procedural (QRS-T) angle was defined according to the treatment strategy as follows: the angle which measured from the post-PCI ECG in patients treated with pPCI; the angle which measured from the ECG taken 90 min after onset of therapy in patients treated with TT.

RESULTS

The baseline (101.9° ± 48.0 vs. 72.1° ± 49.1, p = 0.014) and post-procedural f(QRS-T) angles (95.7° ± 48.1 vs. 58.1° ± 47.1, p = 0.002) were significantly higher in patients who developed in-hospital mortality than the patients who did not develop in-hospital mortality. Also, f(QRS-T) angle measured at 90 min was significantly lower in patients with successful thrombolysis group compared to failed thrombolysis group (53.2° ± 42.8 vs. 77.3° ± 52.9, p = 0.033), whereas baseline f(QRS-T) angle was similar between two groups (78.6° ± 53.4 vs. 78.9° ± 54.0, p = 0.976). Multivariate analysis showed that post-procedural f(QRS-T) angle ≥89.6° (odds ratio: 3.541, 95% confidence interval: 1.235-10.154, p = 0.019), but not baseline f(QRS-T) angle, was independent predictor of in-hospital mortality.

CONCLUSION

f(QRS-T) angle may be used as a beneficial tool for determining high risk patients in acute STEMI. Unlike previous studies, we showed for the first time that that post-procedural f(QRS-T) can predict in-hospital mortality and TT failure.