QRS-T angle: a review

The Effect of Electroconvulsive Therapy on Frontal QRS-T Angle in Psychiatric Patients

Introduction

Electroconvulsive therapy (ECT) is one of the biological therapies that is well tolerated and has a low risk of complications. Acute cardiovascular complications related to ECT such as ventricular arrhythmia, myocardial infarction and cardiac arrest have been recorded. Increased frontal QRS-T (fQRS-T) angle was associated with ventricular arrhythmia, sudden cardiac death and total mortality. In this study, we aimed to evaluate the effect of ECT on the myocardium using electrocardiography (ECG) parameters such as fQRS-T angle, QRS duration, QT and QTc interval.

Methods

A total of 108 patients diagnosed with bipolar disorder (n=36), depressive disorder (n=70) and schizophrenia (n=2) who underwent ECT were included in this study. 12-lead surface ECG of all patients were taken before the ECT, 15 min. after ECT and 24 hour after ECT.

Results

QRS duration, QT interval and corrected QT (QTc) interval were not changed significantly during the follow-up period. However, we found that, fQRS-T angle was significantly increased 15 minutes after ECT compared to baseline angle (p<0.001). We also detected that this increase in fQRS-T angle 15 minutes after ECT was significantly reduced 24 hours after ECT (p=0.031). Meanwhile, there was no significant difference between baseline and 24th hour fQRS-T angle (p=0.154).

Conclusions

In our study, a significant increase in fQRS-T angle was observed 15 min after ECT. However, the fQRS-T angle was found to return to normal after 24 hours. Our findings may indicate that ECT does not have a permanent side effect on the risk of cardiovascular events according to the fQRS-T angle.

The Relationship between Frontal QRS-T Angle and Vitamin D Deficiency

Background and Objectives: A deficiency in serum 25-hydroxyvitamin D levels is associated with a number of cardiovascular situations, such as high blood pressure, heart failure, atherosclerotic heart disease, and peripheral artery disease. The frontal QRS-T angle has recently been proposed as a marker of ventricular repolarization. A wider frontal QRS-T angle has been positively correlated with adverse cardiac events. The objective of our study was to examine the association between serum 25-hydroxyvitamin D level and the frontal QRS-T angle. Materials and Methods: A total of 173 consecutive patients aged 18-60 years undergoing routine cardiology check-up evaluation, and not receiving concurrent vitamin D treatment were included in the study. Patients were classified in three groups, depending on their vitamin D levels, and categorized as follows: Group 1-deficient (<20 ng/mL), Group 2-insufficient (20-29 ng/mL), or Group 3-optimal (≥30 ng/mL). The frontal QRS-T angle was determined using the automated reports generated by the electrocardiography machine. Results: The average age of participants was 45.8 (±12.2) years, and 55.5% of participants were female (p < 0.001). Individuals with low vitamin D concentrations exhibited a wider frontal QRS-T angle. It was determined that vitamin D level is an independent predictive factor for the frontal QRS-T angle. Conclusions: As the levels of 25-hydroxyvitamin D decrease, repolarization time assessed by frontal QRS-T angle is widened. Our findings indicate that lower concentrations of vitamin D may increase the susceptibility to ventricular arrhythmia.

The relationship between QRS-T angle and left ventricular global longitudinal strain in prehypertensive patients

BACKGROUND AND AIM

This study aims to examine the relationship between the QRS-T angle (QRS-Ta) detected on electrocardiography and left ventricular global longitudinal strain (LV-GLS) calculated on echocardiography in prehypertensive patients.

MATERIALS AND METHODS

A total of 300 patients were included in our study, and the median value of QRS-Ta of the entire population was 27.The patients were divided into two groups (supramedian 148 patients, inframedian 152 patients) according to the median value. Statistical analysis was performed between the two groups.

RESULTS

LV-GLS was lower in the supramedian QRS-Ta group [20 (16-26) vs. 21 (16-27); p < 0.001]. A statistical difference was found between the two groups in age (p < 0.001), BMI (p < 0.001), Hs-troponin I (p < 0.001), aortic velocity (p = 0.023) and TAPSE (p = 0.005) parameters except for LV-GLS.The correlation between QRS-Ta and LV-GLS was determined by Spearman's correlation test (p < 0.001).In the multivariable logistic regression analysis model, LV-GLS (OR: 0.365, 95%CI 0.171-0.780, p = 0.009) was one of the independent predictors for increased QRS-Ta. Others were determined as age (p < 0.001) and TAPSE (p = 0.015).

CONCLUSIONS

In this study, a strong relationship was found between QRS-Ta, which is easily calculated by ECG, and LV-GLS, which is an advanced echocardiographic examination, in prehypertensive patients.

QRS-T angle: is it a specific parameter associated with sudden cardiac death in type 2 diabetes? Results from the SURDIAGENE and the Mini-Finland prospective cohorts

AIMS/HYPOTHESIS

Type 2 diabetes is associated with a high risk of sudden cardiac death (SCD), but the risk of dying from another cause (non-SCD) is proportionally even higher. The aim of the study was to identify easily available ECG-derived features associated with SCD, while considering the competing risk of dying from non-SCD causes.

METHODS

In the SURDIAGENE (Survie, Diabete de type 2 et Genetique) French prospective cohort of individuals with type 2 diabetes, 15 baseline ECG parameters were interpreted among 1362 participants (mean age 65 years; HbA1c 62±17 mmol/mol [7.8±1.5%]; 58% male). Competing risk models assessed the prognostic value of clinical and ECG parameters for SCD after adjusting for age, sex, history of myocardial infarction, N-terminal pro b-type natriuretic peptide (NT-proBNP), HbA1c and eGFR. The prospective Mini-Finland cohort study was used to externally validate our findings.

RESULTS

During median follow-up of 7.4 years, 494 deaths occurred including 94 SCDs. After adjustment, frontal QRS-T angle ≥90° (sub-distribution HR [sHR] 1.68 [95% CI 1.04, 2.69], p=0.032) and NT-proBNP level (sHR 1.26 [95% CI 1.06, 1.50] per 1 log, p=0.009) were significantly associated with a higher risk of SCD. Nevertheless, frontal QRS-T angle was the only marker not to be associated with causes of death other than SCD (sHR 1.08 [95% CI 0.84, 1.39], p=0.553 ). These findings were replicated in the Mini-Finland study subset of participants with diabetes (sHR 2.22 [95% CI 1.05, 4.71], p=0.04 for SCD and no association for other causes of death).

CONCLUSIONS/INTERPRETATION

QRS-T angle was specifically associated with SCD risk and not with other causes of death, opening an avenue for refining SCD risk stratification in individuals with type 2 diabetes.

Risk Prediction for Sudden Cardiac Death in the General Population: A Systematic Review and Meta-Analysis

Objective: Identification of SCD risk is important in the general population from a public health perspective. The objective is to summarize and appraise the available prediction models for the risk of SCD among the general population. Methods: Data were obtained searching six electronic databases and reporting prediction models of SCD risk in the general population. Studies with duplicate cohorts and missing information were excluded from the meta-analysis. Results: Out of 8,407 studies identified, fifteen studies were included in the systematic review, while five studies were included in the meta-analysis. The Cox proportional hazards model was used in thirteen studies (96.67%). Study locations were limited to Europe and the United States. Our pooled meta-analyses included four predictors: diabetes mellitus (ES = 2.69, 95%CI: 1.93, 3.76), QRS duration (ES = 1.16, 95%CI: 1.06, 1.26), spatial QRS-T angle (ES = 1.46, 95%CI: 1.27, 1.69) and factional shortening (ES = 1.37, 95%CI: 1.15, 1.64). Conclusion: Risk prediction model may be useful as an adjunct for risk stratification strategies for SCD in the general population. Further studies among people except for white participants and more accessible factors are necessary to explore.

Combined use of frontal plane QRS-T angle and platelet-to-lymphocyte ratio in the risk prediction of ischemic cardiomyopathy in STEMI

BACKGROUND

Frontal plane QRS-T angle (fQRS-T) and platelet-to-lymphocyte ratio (PLR) are highly important parameters that well-predict unfavorable outcomes in patients with ST-elevated myocardial infarction (STEMI).There are limited data on the predictive significance of ischemic cardiomyopathy (I-CMP) from the combination of fQRS-T and PLR in STEMI, compared to using fQRS-T and PLR alone.

AIM

We aimed to evaluate the ability of the combination of fQRS-T and PLR routinely obtained on admission to identify STEMI patients at risk of I-CMP.

METHOD

Six hundred and thirty-eight consecutive patients with STEMI who underwent primary percutaneous coronary intervention between 2018 and 2021 were included. The assessment of I-CMP was conducted through two-dimentional (2D)-echocardiography 6 weeks post-STEMI and I-CMP was defined as a left ventricular ejection fraction (LVEF) of 50% or less. Multivariate logistic regression analysis and receiver operating curve (ROC) analysis were performed to predict the development of I-CMP.

RESULTS

In ROC analysis, the cut-off values of fQRS-T and PLR for best predicting I-CMP were 66.72° and 101.23, respectively. The model using the combination of two markers was the most powerful predictor of I-CMP risk (OR: 3.183, 95% CI: 1.971-5.139, p = .001) when included in a single variable such as high fQRS-T or high PLR (OR: 1.422, 95% CI: 0.870-0.232, p = .160). Additionally, the concomitant presence of high fQRS-T and high PLR exhibited the highest specificity (77%) for I-CMP relative to the individual presence of high fQRS-T (66%) or PLR (49%).

CONCLUSION

The combination of fQRS-T and PLR, which is a simple and cost-effective risk assessment, may serve as a more reliable prognosticator for I-CMP as opposed to the use of fQRS-T and PLR alone for STEMI.

BRAVEHEART: Open-source software for automated electrocardiographic and vectorcardiographic analysis

BACKGROUND AND OBJECTIVES

Electrocardiographic (ECG) and vectorcardiographic (VCG) analyses are used to diagnose current cardiovascular disease and for risk stratification for future adverse cardiovascular events. With increasing use of digital ECGs, research into novel ECG/VCG parameters has increased, but widespread computer-based ECG/VCG analysis is limited because there are no currently available, open-source, and easily customizable software packages designed for automated and reproducible analysis.

METHODS AND RESULTS

We present BRAVEHEART, an open-source, modular, customizable, and easy to use software package implemented in the MATLAB programming language, for scientific analysis of standard 12-lead ECGs acquired in a digital format. BRAVEHEART accepts a wide variety of digital ECG formats and provides complete and automatic ECG/VCG processing with signal denoising to remove high- and low-frequency artifact, non-dominant beat identification and removal, accurate fiducial point annotation, VCG construction, median beat construction, customizable measurements on median beats, and output of measurements and results in numeric and graphical formats.

CONCLUSIONS

The BRAVEHEART software package provides easily customizable scientific analysis of ECGs and VCGs. We hope that making BRAVEHART available will allow other researchers to further the field of ECG/VCG analysis without having to spend significant time and resources developing their own ECG/VCG analysis software and will improve the reproducibility of future studies. Source code, compiled executables, and a detailed user guide can be found at http://github.com/BIVectors/BRAVEHEART. The source code is distributed under the GNU General Public License version 3.

Limits of the spatial ventricular gradient and QRST angles in patients with normal electrocardiograms and no known cardiovascular disease stratified by age, sex, and race

INTRODUCTION

Measurement of the spatial ventricular gradient (SVG), spatial QRST angles, and other vectorcardiographic measures of myocardial electrical heterogeneity have emerged as novel risk stratification methods for sudden cardiac death and other adverse cardiovascular events. Prior studies of normal limits of these measurements included primarily young, healthy, White volunteers, but normal limits in older patients are unknown. The influence of race and body mass index (BMI) on these measurements is also unclear.

METHODS

Normal 12-lead electrocardiograms (ECGs) from a single center were identified. Patients with abnormal cardiovascular, pulmonary, or renal history (assessed by International Classification of Disease [ICD-9/ICD-10] codes) or abnormal cardiovascular imaging were excluded. The SVG and QRST angles were measured and stratified by age, sex, and race. Multivariable linear regression was used to assess the influence of age, BMI, and heart rate (HR) on these measurements.

RESULTS

Among 3292 patients, observed ranges of SVG and QRST angles (peak and mean) differed significantly based on sex, age, and race. Sex differences attenuated with increasing age. Men tended to have larger SVG magnitude (60.4 [46.1-77.8] vs. 52.5 [41.3-65.8] mv*ms, p < .0001) and elevation, and more anterior/negative SVG azimuth (-14.8 [-25.1 to -4.3] vs. 1.3 [-9.8 to 10.5] deg, p < .0001) compared to women. Men also had wider QRST angles. Observed ranges varied significantly with BMI and HR. SVG and QRST angle measurements were robust to different filtering bandwidths and moderate fiducial point annotation errors, but were heavily affected by changes in baseline correction.

CONCLUSIONS

Age, sex, race, BMI, and HR significantly affect the range of SVG and QRST angles in patients with normal ECGs and no known cardiovascular disease, and should be accounted for in future studies. An online calculator for prediction of these "normal limits" given demographics is provided at https://bivectors.github.io/gehcalc/.

Comparison of frontal QRS-T angle and inflammatory parameters between the patients with drug-naive first episode psychosis and healthy controls

BACKGROUND

Frontal QRS-T (fQRS-T) angle is a novel marker to predict many cardiovascular diseases. The present study aims to compare the fQRS-T angle of first episode psychosis (FEP) patients and healthy controls (HC) and evaluate the relationship between fQRS-T angle and blood count-related inflammatory markers such as neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and monocyte to high-density lipoprotein cholesterol ratio (MHR).

METHODS

Electrocardiogram (ECG) and complete blood count (CBC) of 63 patients who were diagnosed with drug-naive FEP in the psychiatry clinic of a training and research hospital and 78 healthy controls (HC) individuals who had applied to the health committee polyclinic for recruitment or pre-military examination between 2016 and 2021 were included.

RESULTS

fQRS-T angle was wider in FEP patients (55.5o) than in healthy controls (22o) (p < .001). NLR, PLR, and MHR were higher in FEP patients than in healthy controls (p = .001, p < .001, and p < .001, respectively). fQRS-T angle was positively correlated with NLR (r = 0.52 and p < .001) and MHR (r = 0.39 and p = .002) in FEP patients. NLR (t = 2.196 and p = .032) and MHR (t = 5.469 and p < .001) values were found to be the predictors of fQRS-T angle in FEP patients.

CONCLUSION

In summary, we can conclude that patients with FEP tend to exhibit a wider fQRS-T angle compared to their healthy controls. Additionally, the values of NLR and MHR could potentially serve as useful indicators for predicting the fQRS-T angle in FEP patients. Conducting subsequent long-term studies could provide deeper insights into the interpretation of the fQRS-T angle and its potential connection to cardiovascular diseases in schizophrenia patients.

Accelerated DNA methylation age plays a role in the impact of cardiovascular risk factors on the human heart

BACKGROUND

DNA methylation (DNAm) age acceleration (AgeAccel) and cardiac age by 12-lead advanced electrocardiography (A-ECG) are promising biomarkers of biological and cardiac aging, respectively. We aimed to explore the relationships between DNAm age and A-ECG heart age and to understand the extent to which DNAm AgeAccel relates to cardiovascular (CV) risk factors in a British birth cohort from 1946.

RESULTS

We studied four DNAm ages (AgeHannum, AgeHorvath, PhenoAge, and GrimAge) and their corresponding AgeAccel. Outcomes were the results from two publicly available ECG-based cardiac age scores: the Bayesian A-ECG-based heart age score of Lindow et al. 2022 and the deep neural network (DNN) ECG-based heart age score of Ribeiro et al. 2020. DNAm AgeAccel was also studied relative to results from two logistic regression-based A-ECG disease scores, one for left ventricular (LV) systolic dysfunction (LVSD), and one for LV electrical remodeling (LVER). Generalized linear models were used to explore the extent to which any associations between biological cardiometabolic risk factors (body mass index, hypertension, diabetes, high cholesterol, previous cardiovascular disease [CVD], and any CV risk factor) and the ECG-based outcomes are mediated by DNAm AgeAccel. We derived the total effects, average causal mediation effects (ACMEs), average direct effects (ADEs), and the proportion mediated [PM] with their 95% confidence intervals [CIs]. 498 participants (all 60-64 years) were included, with the youngest ECG heart age being 27 and the oldest 90. When exploring the associations between cardiometabolic risk factors and Bayesian A-ECG cardiac age, AgeAccelPheno appears to be a partial mediator, as ACME was 0.23 years [0.01, 0.52] p = 0.028 (i.e., PM≈18%) for diabetes, 0.34 [0.03, 0.74] p = 0.024 (i.e., PM≈15%) for high cholesterol, and 0.34 [0.03, 0.74] p = 0.024 (PM≈15%) for any CV risk factor. Similarly, AgeAccelGrim mediates ≈30% of the relationship between diabetes or high cholesterol and the DNN ECG-based heart age. When exploring the link between cardiometabolic risk factors and the A-ECG-based LVSD and LVER scores, it appears that AgeAccelPheno or AgeAccelGrim mediate 10-40% of these associations.

CONCLUSION

By the age of 60, participants with accelerated DNA methylation appear to have older, weaker, and more electrically impaired hearts. We show that the harmful effects of CV risk factors on cardiac age and health, appear to be partially mediated by DNAm AgeAccelPheno and AgeAccelGrim. This highlights the need to further investigate the potential cardioprotective effects of selective DNA methyltransferases modulators.

Electrocardiographic Associations of Cardiac Biomarkers and Cardiac Magnetic Resonance Measures of Fibrosis in the Multiethnic Study of Atherosclerosis (MESA)

Abnormalities in myocardial substrate, including diffuse and replacement fibrosis, increase the risk of cardiovascular disease (CVD). Data are sparse on whether electrocardiogram (ECG) measures, coupled with circulating biomarkers, may aid in identifying cardiac fibrosis. This study aimed to determine whether 12-lead ECG and biomarkers together augment the prediction of cardiac fibrosis in participants who are free of known CVD. This is a cross-sectional analysis in the MESA (Multiethnic Study of Atherosclerosis) study at visit 5 (2010 to 2012), with measurements of biomarkers (cardiac troponin T and growth differentiation factor-15), gadolinium-enhanced cardiac magnetic resonance imaging, and ECG. Logistic regression associations of ECG measures with cardiac magnetic resonance surrogates of fibrosis (highest quartile extracellular volume [interstitial fibrosis] and late gadolinium enhancement [replacement fibrosis]) were adjusted for demographics and risk factors. Using the C-statistic, we evaluated whether adding ECG measures and biomarkers to clinical characteristics improved the prediction of either type of fibrosis. There were 1,170 eligible participants (aged 67.1 ± 8.6 years). Among the ECG measures, QRS duration (odds ratio [OR] 1.41 per 10 ms, 95% confidence interval [CI] 1.10 to 1.81), major ST-T abnormalities (OR 3.03, 95%CI 1.20, 7.65), and abnormal QRS-T angle (OR 6.32, 95%CI 3.00, 13.33) were associated with replacement fibrosis, whereas only abnormal QRS-T angle (OR 3.05, 95%CI,1.69, 5.48) was associated with interstitial fibrosis. ECG markers, in addition to clinical characteristics, improved the prediction of replacement fibrosis (p = 0.002) but not interstitial fibrosis. The addition of cardiac troponin T and growth differentiation factor-15 to the ECG findings did not significantly improve the model discrimination for either type of cardiac fibrosis. In CVD free participants, simple ECG measures are associated with replacement fibrosis and interstitial fibrosis. The addition of these measures improves identification of replacement but not interstitial fibrosis. These findings may help refine the identification of myocardial scar in the general population.

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.

Effect of Smokeless Tobacco (Maras Powder) on the Epicardial Fat Thickness and Ventricular Repolarization Parameters

Background and Objectives: Smokeless tobacco (ST) use has recently become an alternative to cigarettes, and it has been concluded that ST is at least as harmful as cigarettes. ST use is thought to play a role in the pathogenesis of arrhythmia by affecting ventricular repolarization. In this study, we aimed to examine the relationships of Maras powder (MP), one of the ST varieties, with epicardial fat thickness and new ventricular repolarization parameters, which have not previously been described. Materials and Methods: A total of 289 male individuals were included in this study between April 2022 and December 2022. Three groups, 97 MP users, 97 smokers, and 95 healthy (non-tobacco), were compared according to electrocardiographic and echocardiographic data. Electrocardiograms (ECG) were evaluated with a magnifying glass by two expert cardiologists at a speed of 50 m/s. Epicardial fat thickness (EFT) was measured by echocardiography in the parasternal short- and long-axis images. A model was created with variables that could affect epicardial fat thickness. Results: There were no differences between the groups regarding body mass index (p = 0.672) and age (p = 0.306). The low-density lipoprotein value was higher in the MP user group (p = 0.003). The QT interval was similar between groups. Tp-e (p = 0.022), cTp-e (p = 0.013), Tp-e/QT (p =0.005), and Tp-e/cQT (p = 0.012) were higher in the MP user group. While the Tp-e/QT ratio did not affect EFT, MP predicted the epicardial fat thickness (p < 0.001, B = 0.522, 95%CI 0.272-0.773). Conclusions: Maras powder may play a role in ventricular arrhythmia by affecting EFT and causing an increase in the Tp-e interval.

The association between frontal QRS-T angle and reverse dipper status in newly diagnosed hypertensive patients

The frontal QRS-T angle (fQRS-T angle) in ECG is a new measure of myocardial repolarization, in which a higher fQRS-T angle is linked with worse cardiac outcomes. Reverse dipper hypertension is also linked to poor cardiac outcomes. The purpose of this study was to investigate the association between the fQRS-T angle and reverse dipper status in individuals newly diagnosed with hypertension who did not have left ventricular hypertrophy (LVH). The investigation recruited 171 hypertensive individuals without LVH who underwent 24-h ambulatory blood pressure monitoring (ABPM). On the basis of the findings of 24-h ABPM, the study population was categorized into the following three groups: patients with dipper hypertension, non-dipper hypertension, and reverse dipper hypertension. LVH was defined by echocardiography. The fQRS-T angle was measured using the 12-lead ECG. The fQRS-T angle in individuals with reverse dipper hypertension was substantially greater than in patients with and without dipper hypertension (51° ± 28° vs. 28° ± 22° vs. 39° ± 25°, respectively, P < 0.001). The fQRS-T angle (odds ratio: 1.040, 95% confidence interval: 1.016-1.066; P = 0.001) was independently associated with reverse dipper hypertension according to multivariate analysis. In receiver operating characteristic curve analysis, the fQRS-T angle to predict reverse dipper hypertension was 33.5° with 76% sensitivity and 71% specificity. This study showed that an increased fQRS-T angle was associated with reverse dipper hypertension in newly diagnosed hypertensive patients without LVH.

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.

Genetic architecture of spatial electrical biomarkers for cardiac arrhythmia and relationship with cardiovascular disease

The 3-dimensional spatial and 2-dimensional frontal QRS-T angles are measures derived from the vectorcardiogram. They are independent risk predictors for arrhythmia, but the underlying biology is unknown. Using multi-ancestry genome-wide association studies we identify 61 (58 previously unreported) loci for the spatial QRS-T angle (N = 118,780) and 11 for the frontal QRS-T angle (N = 159,715). Seven out of the 61 spatial QRS-T angle loci have not been reported for other electrocardiographic measures. Enrichments are observed in pathways related to cardiac and vascular development, muscle contraction, and hypertrophy. Pairwise genome-wide association studies with classical ECG traits identify shared genetic influences with PR interval and QRS duration. Phenome-wide scanning indicate associations with atrial fibrillation, atrioventricular block and arterial embolism and genetically determined QRS-T angle measures are associated with fascicular and bundle branch block (and also atrioventricular block for the frontal QRS-T angle). We identify potential biology involved in the QRS-T angle and their genetic relationships with cardiovascular traits and diseases, may inform future research and risk prediction.

The predictive value of electrocardiographic polarization parameters on appropriate ICD shock in primary prevention heart failure patients

OBJECT

The effect of frontal QRS-T angle, Tp-e and Tp-e/QT ratio on cardiac events have been shown in many studies. In this study, we aimed to determine the prognostic value of frontal QRS-T angle, TPe and Tp-e/QT ratio on ICD shock in patients who had ICD (Implantable Cardioverter Defibrillator) implanted due to heart failure with reduced ejection fraction (HFrEF).

MATERIAL AND METHOD

158 patients with HFrEF who had previous ICD implantation were retrospectively analyzed. 27 patients were found to have an appropriate shock. Frontal QRS-T angle, Tp-e interval, Tp-e/QT ratio were calculated by evaluating the basal ECG records of the patients. Comparisons of these arrhythmogenic predictors were made in patients with and without ICD shock at follow-up.

RESULT

When 158 patients with previous ICD implantation were analyzed in two groups with and without ICD shock, the number of patients with frontal QRS-T angle >120°, Tp-e interval > 105 ms, Tp-e/QT > 0.2 in the shock group (n: 27) was found to be high with a different significance (p:<0.01, p:<0.01, p:<0.01). There was no significant difference between the two groups regarding other ECG parameters such as QRS duration, QT interval, PR interval, fragmented QRS and positive T wave. In addition, more amiodarone use was observed in the shock group, and more hyperlipidemia cases were observed in the non-shocked group (p:0.01; p:<0.01).

CONCLUSION

Increased frontal QRS-T angle, Tp-e interval, and Tp-e/QT ratio are arrhythmogenic parameters and predict appropriate ICD shock.

Comparison of Frontal QRS-T Angle in Patients with Panic Disorder and Healthy Control Group: A Preliminary Study

Background

Autonomic instability is blamed for panic disorder pathophysiology. It has been suggested that this may raise the risk of cardiovascular disease. A new proposal for ventricular depolarization and repolarization impairment is the frontal QRS-T angle.

Methods

In this cross-sectional study, 61 patients with panic disorder and 73 healthy controls were included. The severity of panic disorder was evaluated using the Severity Measure for Panic Disorder-Adult. Electrocardiography, echocardiography, hemogram, and biochemistry data were recorded.

Results

Patients with panic disorder had a greater frontal QRS-T angle than healthy controls. In panic disorder patients, the values for hemoglobin, eosinophil count, and high-density lipoprotein cholesterol were all significantly lower than healthy controls. In comparison to healthy controls, panic disorder patients had significantly higher values for total cholesterol, fasting triglycerides, low-density lipoprotein cholesterol, platelet-to-lymphocyte ratio, and monocyte-to-high-density lipoprotein cholesterol ratio. Significant correlations were found between frontal QRS-T and Severity Measure for Panic Disorder-Adult, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio. The frontal QRS-T value is positively and significantly predicted by the neutrophil-to-lymphocyte ratio value according to the linear regression analysis for the frontal QRS-T angle [F(6.54) = 8.375, P < .001, adjusted R 2: 0.424].

Conclusion

The current study found that the frontal QRS-T angle increased with the severity of the disease in patients with panic disorder. Frontal QRS-T angle may help to estimate cardiovascular disease risk in patients with panic disorder. This relationship may be necessary in terms of cardiovascular events and inflammatory conditions.

Frontal QRS - T angle is associated with severity and prognosis of acute pulmonary embolism

INTRODUCTION

The pathological effects of acute pulmonary embolism (APE) on the right ventricle are one of the most important determinants of mortality in patients with APE. Frontal QRS-T angle (fQRSTa) predicts ventricular pathology and poor prognosis in many different cardiovascular diseases. In this study, we investigated whether there is a significant relationship between fQRSTa and APE severity.

MATERIAL AND METHODS

A total of 309 patients were included in this retrospective study. The severity of APE was classified as massive (high risk), submassive (intermediate risk), or nonmassive (low risk). fQRSTa calculated from standard ECGs.

RESULTS

fQRSTa was significantly higher in massive APE patients (p < 0.001). fQRSTa was also found to be significantly higher in the in-hospital mortality group (p < 0.001). fQRSTa was an independent risk factor for the development of massive APE (odds ratio:1.033; 95% CI: 1.012-1.052; p < 0.001).

CONCLUSION

Our study showed that increased fQRSTa predicts high-risk APE patients and mortality in APE patients.

The predictive value of Tp-Te interval, Tp-Te/QT ratio, and QRS-T angle of idiopathic ventricular tachycardia in patients with ventricular premature beats

BACKGROUND

Identify idiopathic ventricular tachycardia in patients with ventricular premature beats was required to have effectively treatment.

HYPOTHESIS

The aim of this study is to investigate the predictive value of Tp-Te interval, Tp-Te/QT ratio, and QRS-T angle of idiopathic ventricular tachycardia in patients with idiopathic ventricular premature beats.

METHODS

One hundred and seventy-eight patients who had undergone premature ventricular complex/ventricular tachycardia (PVC/VT) ablation between January 1, 2020 and August 30, 2022 constituted our study population as ventricular arrhythmia group. Seventy-five healthy people were selected as control group. Patients with no episode of VT were classified as PVC group, while with any episode of VT that has the same morphology with PVC were classified as PVC with VT group. Patients in PVC with VT group were divided into two groups: nonsustained VT group (duration of any episode of VT below 30 s) and sustained VT group (duration of any episode of VT over 30 s). Tp-Te interval, Tp-Te/QT ratio and QRS-T angle were compared in groups.

RESULTS

Tp-Te interval, Tp-Te/QT ratio and patients with increased QRS-T angle in PVC with VT group were higher or more than those in PVC group (p < .001). The value of combined diagnosis of these indexes was higher. Tp-Te interval was longer in the sustained VT group compared to the nonsustained VT group (p = .009).

CONCLUSION

Tp-Te interval, Tp-Te/QT ratio, and QRS-T angle may have a predictive value of presence of idiopathic VT in patients with premature beats and the combined prediction of these indexes is more valuable. Tp-Te interval maybe helpful for prediction of sustained idiopathic VT.

The Relationship between the Frontal QRS-T Angle on ECG and Physical Activity Level in Young Adults

BACKGROUND

The heart's electrical activity has been the subject of numerous research concerning various physiological parameters. The frontal QRS-T angle (FQRST) is an advanced ECG variable with clinical epidemiological utility. This study aimed to determine the relationship between FQRST and physical activity exposure among young adults.

METHODS

We recorded the ECG with 12 leads of 124 participants (mean age 20.28 ± 2.23 years, age range 18-27 years). Next, we measured their physical activity level (PAL) with the International Physical Activity Questionnaire-Short Form (IPAQ), which categorizes activity into three classes: low, moderate, or high.

RESULTS

An inferential analysis, based on the Kruskal-Wallis H test and Mann-Whitney U test, revealed a statistically significant difference in FQRST between the three groups of subjects, classified by their PAL (p < 0.001). We also identified a significant regression model between the body mass index (BMI) and the FQRST (p < 0.001).

CONCLUSIONS

The physical activity regime of young adults significantly influences the concordance between ventricular depolarization and repolarization, reflected in the FQRST's width. Also, we found a regression model between FQRST and BMI with statistical significance.

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.

QRS-T angle as a predictor of pulmonary arterial hypertension: A review

Spatial QRS-T angle is a vector projection of ventricular gradient, reflecting the heterogeneity of ventricular repolarization. The QRS vector is projected into three dimensional (3D) space to obtain the frontal QRSf vector and Tf vector. The frontal QRS-T Angle can be obtained by simple calculation. In several studies of diseases that cause pulmonary hypertension, there has been evidence that changes in the QRS-T Angle can predict disease. Electrocardiogram (ECG) is a cheap and noninvasive test, and its clinical significance in the diagnosis of pulmonary hypertension should be further studied.

The Importance of Frontal QRS-T Angle in Predicting the Effectiveness and Success of Thrombolytic Therapy in Patients With Acute Pulmonary Embolism

OBJECTIVE

The frontal QRS-T angle (fQRS-T) is associated with myocardial ischemia and ventricular arrhythmias. On the other hand, acute pulmonary embolism (APE) is a major risk factor for cardiac adverse events. This research aimed to determine whether the fQRS-T, a marker of ventricular heterogeneity, can be used to predict successful thrombolytic therapy in patients with APE.

METHODS

This was a retrospective observational study. Patients diagnosed with APE and hospitalized in the intensive care unit between 2020 and 2022 were included in the research. A total of 136 individuals with APEs were enrolled in this research. The patients were divided into two groups: thrombolytic-treated (n=64) and non-treated (moderate to severe risk, n=72). An ECG was conducted for each patient, and echocardiography was performed.

RESULTS

The mean age of the thrombolytic group was 58.2±17.6 years, with 35 females (55.1% of the group) and 29 males (44.9%). The non-thrombolytic group had a mean age of 63.1±16.2, with 41 females (56.5%) and 31 males (43.5%). Respiratory rate, heart rate, and fQRS-T were higher in the thrombolytic group, and oxygen saturation ratio and systolic and diastolic blood pressure were higher in the non-thrombolytic group (p=0.006, p<0.001, p=0.021; p<0.001, p=0.015, p<0.001, respectively). In the thrombolytic therapy group, comparing pre- and post-treatment ECG data revealed a statistically significant change in the fQRS-T value (p=0.019).

CONCLUSION

The fQRS-T may provide important clues for the successful treatment of APEs.

Relationship Between Atrial Fibrillation Recurrence and Frontal QRS-T Angle After Effective Cardioversion

OBJECTIVE

Maintaining sinus rhythm is important in the management of atrial fibrillation (AF). After cardioversion, there is a significant probability of AF recurrence. There is limited research on the relationship between AF recurrence and ECG parameters. This study aimed to evaluate whether the frontal plane QRS-T angle (fQRS-T), a predictor of ventricular heterogeneity, could be used to predict AF recurrence following cardioversion.

METHODS

The study was conducted as a retrospective observational study. Patients diagnosed with acute-onset AF for the first time were included in the study. All patients underwent an ECG after cardioversion, and ECG parameters were evaluated. The patients were separated into two groups based on the presence of AF recurrence during hospitalization after cardioversion. The relationship between the fQRS-T and AF recurrence was also examined.

RESULTS

A total of 162 patients, comprising 68 women (41.9%) and 94 men (58.1%) with an average age of 59.4±6.5 years, were enrolled in the research. Based on the patient monitoring device findings, patients were separated into two groups: non-recurrent AF (n=118) and recurrent AF (n=44). P-wave duration was significantly longer in the recurrence group (p=0.009). The recurrence group's mean fQRS-T was significantly higher (p<0.001). AF recurrence was substantially higher in patients with fQRS-T >90 ° compared to those with fQRS-T ≤90 ° (56.1% vs. 14.2%, p <0.001). Increased fQRS-T>93.7 ° indicated AF recurrence with 78.3% sensitivity and 83.4% specificity (AUC {area under curve}:0.748, p < 0.001). In multivariate analysis, fQRS-T was revealed to be an early indicator of recurrent AF (OR: 1.882, 95%CI: 1.358-2.881, p<0.001).

CONCLUSION

The fQRS-T, an easily determinable parameter from automatic identification ECG recordings, may be useful for predicting the early return of AF after successful cardioversion.

The Significance of Frontal Plane QRS-T Angle for Estimating Non-Dipper Hypertension

OBJECTIVE

The frontal QRS-T angle (fQRS-T) is linked to myocardial ischemia and ventricular arrhythmias. On the other hand, non-dipper hypertension is a risk factor for cardiac adverse events. The objective of this research was to determine whether the fQRS-T, a marker of ventricular heterogeneity, could be used to predict non-dipper hypertensive individuals in the lack of left ventricular hypertrophy.

METHODS

The observational study was carried out retrospectively. Patients diagnosed with hypertension were included in this study. Blood tests were routinely conducted for all patients. Electrocardiography (ECG) was conducted for each patient and echocardiography was performed. Blood pressure (BP) values were collected from the ambulatory Holter records. According to ambulatory Holter monitoring, the individuals were separated into two groups. The association between fQRS-T and hypertension was investigated.

RESULTS

The research involved 123 patients, with an average age of 51.85±8.22 years, comprising 76 women (61.8%) and 47 males (38.2%). According to ambulatory Holter monitoring, patients were separated into dippers (n=65) and non-dippers (n=58). There were no statistically significant in the laboratory and echocardiographic variables (p>0.05). QT dispersion (QTd) and fQRS-T were substantially greater in the non-dipper group than in the dipper group (p=0.043 and p<0.001, respectively). Independent determinants of non-dipper status were determined by univariate and multivariate logistic regression analyses. fQRS-T was found to be the only independent indicator of non-dipper status (OR: 1.03, 95%CI: 1.02-1.06, p<0.001).

CONCLUSION

The fQRS-T may be a useful marker for estimating non-dipper hypertensive individuals in the lack of left ventricular hypertrophy.

Electrocardiographic Parameters Associated with Adverse Outcomes in Children with Cardiomyopathies

Cardiomyopathies have a low prevalence in children and thus may lead to malignant ventricular arrhythmias or the progression of heart failure, resulting in death. In adults, the QRS-T angle derived from ECG has been associated with adverse outcomes in patients with hypertrophic and dilated cardiomyopathies. We aimed to assess the electrocardiographic parameters, including QRS-T angle, associated with adverse cardiac events in children with cardiomyopathies. Forty-two children with cardiomyopathies were included in this study: 19 with dilated cardiomyopathy, 17 with hypertrophic cardiomyopathy, and 6 with left ventricular non-compaction. Additionally, 19 control subjects were recruited. In terms of ECG parameters, the QRS-T angle was significantly greater among patients with adverse outcomes compared to patients without the end points of the study (133° vs. 65°, p < 0.001). On Kaplan−Meier survival curves, QRS-T angle > 120°, increased serum concentrations of NT-proBNP and troponin I levels as well as greater NYHA or Ross scale were associated with the greatest risk of unfavorable outcome. The QRS-T angle appears to be a valuable component of 12-lead ECG interpretation, and might be helpful in outlining patients with the greatest cardiovascular risk. Additionally, serum biomarkers such as NT-proBNP (p = 0.003) and troponin (p < 0.001) are useful in outlining patients with the worst survival.

An electrocardiography score predicts heart failure hospitalization or death beyond that of cardiovascular magnetic resonance imaging

The electrocardiogram (ECG) and cardiovascular magnetic resonance imaging (CMR) provide powerful prognostic information. The aim was to determine their relative prognostic value. Patients (n = 783) undergoing CMR and 12-lead ECG with a QRS duration < 120 ms were included. Prognosis scores for one-year event-free survival from hospitalization for heart failure or death were derived using continuous ECG or CMR measures, and multivariable logistic regression, and compared. Patients (median [interquartile range] age 55 [43-64] years, 44% female) had 155 events during 5.7 [4.4-6.6] years. The ECG prognosis score included (1) frontal plane QRS-T angle, and (2) heart rate corrected QT duration (QTc) (log-rank 55). The CMR prognosis score included (1) global longitudinal strain, and (2) extracellular volume fraction (log-rank 85). The combination of positive scores for both ECG and CMR yielded the highest prognostic value (log-rank 105). Multivariable analysis showed an association with outcomes for both the ECG prognosis score (log-rank 8.4, hazard ratio [95% confidence interval] 1.29 [1.09-1.54]) and the CMR prognosis score (log-rank 47, hazard ratio 1.90 [1.58-2.28]). An ECG prognosis score predicted outcomes independently of CMR. Combining the results of ECG and CMR using both prognosis scores improved the overall prognostic performance.

The Effect of Low-Flow and Normal-Flow Desflurane Anesthesia on the Frontal QRS-T Angle in Patients Undergoing Rhinoplasty Operation: A Randomized Prospective Study

Introduction: Low-flow anesthesia (LFA) has gained more interest worldwide owing to its economic and ecological advantages compared to normal-flow anesthesia (NFA). Desflurane is one of the commonly used anesthetic agents for LFA, but it may prolong myocardial repolarization. Frontal QRS-T angle (f[QRS-T]a) is a novel marker of myocardial repolarization. To our knowledge, no study has compared the effect of LFA and NFA on f(QRS-T)a. In this study, we aimed to compare the effect of the LFA and NFA with desflurane on f(QRS-T)a in patients undergoing rhinoplasty operation.

Methods: A total of 80 patients undergoing rhinoplasty operations were included in this prospective study. The patients were randomized into two groups as follows: LFA (n = 40) and NFA (n = 40). The frontal QRS-T angle was calculated from the automatic report of the electrocardiography device (Nihon Kohden, Tokyo, Japan). It was recorded at the following time points: T1: preoperative (basal), T2: immediately after anesthesia induction, T3: immediately after endotracheal intubation, T4: 5 min after endotracheal intubation, T5: 15 min after endotracheal intubation, T6: 30 min after endotracheal intubation, T7: 60 min after endotracheal intubation, T8: end of the operation, T9: 15 min after the end of the operation.

Results: Baseline clinical characteristics and laboratory parameters were similar between the two groups. In the LFA group, f(QRS-T)a was significantly increased at only the T3 time point when compared to T1 (P = 0.003). However, in the NFA group, f(QRS-T)a was significantly increased at T3, T4, T5, T6, T7, T8, and T9 time points when compared to the T1 value (P < 0.05, for all). On the other hand, fQRS-Ta was significantly higher in the NFA group than in the LFA group at T4, T5, and T6 time points. 

Conclusion: In our study, we have shown for the first time that NFA significantly increased the f(QRS-T)a, whereas LFA did not significantly increase the f(QRS-T)a except for immediately after the endotracheal intubation. It was also detected that f(QRS-T)a was significantly higher in the NFA group compared to that in the LFA group. Therefore, it can be concluded that LFA has more protective effects on myocardial repolarization than NFA.

Improved evaluation of left ventricular hypertrophy using the spatial QRS-T angle by electrocardiography

Electrocardiographic (ECG) signs of left ventricular hypertrophy (LVH) lack sensitivity. The aim was to identify LVH based on an abnormal spatial peaks QRS-T angle, evaluate its diagnostic performance compared to conventional ECG criteria for LVH, and its prognostic performance. This was an observational study with four cohorts with a QRS duration < 120 ms. Based on healthy volunteers (n = 921), an abnormal spatial peaks QRS-T angle was defined as ≥ 40° for females and ≥ 55° for males. In other healthy volunteers (n = 461), the specificity of the QRS-T angle to detect LVH was 96% (females) and 98% (males). In patients with at least moderate LVH by cardiac imaging (n = 225), the QRS-T angle had a higher sensitivity than conventional ECG criteria (93–97% vs 13–56%, p < 0.001 for all). In clinical consecutive patients (n = 783), of those who did not have any LVH, 238/556 (43%) had an abnormal QRS-T angle. There was an association with hospitalization for heart failure or all-cause death in univariable and multivariable analysis. An abnormal QRS-T angle rarely occurred in healthy volunteers, was a mainstay of moderate or greater LVH, was common in clinical patients without LVH but with cardiac co-morbidities, and associated with outcomes.

Intra-subject stability of different expressions of spatial QRS-T angle and their relationship to heart rate

Three-dimensional angle between the QRS complex and T wave vectors is a known powerful cardiovascular risk predictor. Nevertheless, several physiological properties of the angle are unknown or poorly understood. These include, among others, intra-subject profiles and stability of the angle relationship to heart rate, characteristics of angle/heart-rate hysteresis, and the changes of these characteristics with different modes of QRS-T angle calculation. These characteristics were investigated in long-term 12-lead Holter recordings of 523 healthy volunteers (259 females). Three different algorithmic methods for the angle computation were based on maximal vector magnitude of QRS and T wave loops, areas under the QRS complex and T wave curvatures in orthogonal leads, and weighted integration of all QRS and T wave vectors moving around the respective 3-dimensional loops. These methods were applied to orthogonal leads derived either by a uniform conversion matrix or by singular value decomposition (SVD) of the original 12-lead ECG, giving 6 possible ways of expressing the angle. Heart rate hysteresis was assessed using the exponential decay models. All these methods were used to measure the angle in 659,313 representative waveforms of individual 10-s ECG samples and in 7,350,733 individual beats contained in the same 10-s samples. With all measurement methods, the measured angles fitted second-degree polynomial regressions to the underlying heart rate. Independent of the measurement method, the angles were found significantly narrower in females (p &lt; 0.00001) with the differences to males between 10o and 20o, suggesting that in future risk-assessment studies, different angle dichotomies are needed for both sexes. The integrative method combined with SVD leads showed the highest intra-subject reproducibility (p &lt; 0.00001). No reproducible delay between heart rate changes and QRS-T angle changes was found. This was interpreted as a suggestion that the measurement of QRS-T angle might offer direct assessment of cardiac autonomic responsiveness at the ventricular level.

The relationship of frontal QRS-T angle between patients with newly diagnosed true and white coat hypertension

OBJECTIVES

The frontal QRS-T (f-QRST) angle is a measure of depolarization and repolarization heterogeneity and may be a predictor of poor ventricular health. We aimed to investigate whether the f-QRST angle indicates myocardial damage and predicts newly diagnosed true hypertension (HT) in patients with white coat hypertension.

METHODS

We measured the f-QRST angle of 63 subjects with WHC and 105 patients with newly diagnosed HT. Laboratory tests and ABPM were followed up in all patients. The f-QRST angle was calculated on the surface ECGs.

RESULTS

Of the patients in the study, 38.9% were female and 61.1% were male. The mean age was calculated as 59 ± 11 years. A comparison between both groups with the f-QRST angles was seen to be statistically significantly higher in the true HT group. The results of the receiving operating characteristic curve showed that the AUC value of the f-QRST angle was 0.94 (95% confidence interval, 0.91-0.97), the cutoff value was 60.5°, the sensitivity was 89.5%, and the specificity was 81%.

CONCLUSION

In our study, the f-QRST angle was found to be lower in patients with WHC than in true hypertensive patients. We think that ECG, which is a simple test, can be used to distinguish between true HT and WHC.

Correlation between frontal QRS‐T angle, Tp‐e interval, and Tp‐e/ QT ratio to coronary artery severity assessed with SYNTAX score in stable coronary artery disease patients

Background

Methods

Results

Conclusions

Deep-Learning-Based Estimation of the Spatial QRS-T Angle from Reduced-Lead ECGs

The spatial QRS-T angle is a promising health indicator for risk stratification of sudden cardiac death (SCD). Thus far, the angle is estimated solely from 12-lead electrocardiogram (ECG) systems uncomfortable for ambulatory monitoring. Methods to estimate QRS-T angles from reduced-lead ECGs registered with consumer healthcare devices would, therefore, facilitate ambulatory monitoring. (1) Objective: Develop a method to estimate spatial QRS-T angles from reduced-lead ECGs. (2) Approach: We designed a deep learning model to locate the QRS and T wave vectors necessary for computing the QRS-T angle. We implemented an original loss function to guide the model in the 3D space to search for each vector's coordinates. A gradual reduction of ECG leads from the largest publicly available dataset of clinical 12-lead ECG recordings (PTB-XL) is used for training and validation. (3) Results: The spatial QRS-T angle can be estimated from leads {I, II, aVF, V2} with sufficient accuracy (absolute mean and median errors of 11.4° and 7.3°) for detecting abnormal angles without sacrificing patient comfortability. (4) Significance: Our model could enable ambulatory monitoring of spatial QRS-T angles using patch- or textile-based ECG devices. Populations at risk of SCD, like chronic cardiac and kidney disease patients, might benefit from this technology.

FRONTAL QRS-T AÇISI İLE AMBULATUAR 24 SAAT HOLTERDE PREMATÜR VENTRİKÜLER KONTRAKSİYON YÜKÜ ARASINDAKİ İLİŞKİ

AMAÇ Sık prematür ventriküler kontraksiyonlar (PVK), ventriküler fonksiyonun bozulmasına veya ventriküler kavitelerin genişlemesine neden olabilir. Frontal düzlem QRS-T [f(QRS-T)] açısı, miyokardın elektrofizyolojik özelliklerindeki kararsızlığın bir göstergesidir ve aritmilerle ilişkilidir. Bu çalışma, ventriküler repolarizasyon heterojenitesinin bir belirteci olarak f(QRS-T) açısının, ambulatuar 24 saatlik holterde prematüre ventriküler kontraksiyon yükünü tahmin edip etmediğini araştırmayı amaçlamıştır. METHOD Çalışmada 100 hasta mevcuttu. Hastalar 24 saatlik Holter izleminde PVK yüklerine göre “sık PVK” ve “nadir PVK” olarak iki gruba ayrıldı. Laboratuar ve frontal plan QRS-T açısı dahil olmak üzere bazı ambulatuar elektrokardiyografi parametreleri iki grup arasında karşılaştırıldı. BULGULAR Frontal QRS-T açısı (63.34±37.86°'ye karşı 23.46±14.29° p

Empagliflozin has favourable effect on frontal plane QRS-T angle in diabetic patients with cardiovascular disease

WHAT IS KNOWN AND OBJECTIVE

Empagliflozin treatment is significantly associated with lower risk of cardiovascular events in patients with diabetes mellitus (DM) independent of its antihyperglycemic effect. However, little is known regarding the impact of empagliflozin on electrocardiography (ECG) parameters. This study aimed to investigate whether empagliflozin has favourable effect on frontal plane QRS-T (fQRST) angle, which is an ECG sign of ventricular repolarization heterogeneity, in patients with type 2 DM.

METHODS

We prospectively enrolled 111 patients with known diagnosis of type 2 DM who newly prescribed empagliflozin on top of their standard anti-diabetic therapy. Patients were divided into two groups according to presence or absence of cardiovascular disease (CVD) at baseline and followed-up for 6 months. The impact of empagliflozin treatment on fQRST angle was investigated and patient groups were compared regarding the pre- and post-treatment fQRST angle.

RESULTS AND DISCUSSION

Among 111 patients, 32 (28.8%) had CVD and 79 (71.2%) had no CVD. Empagliflozin treatment lead a significant decrease in the mean fQRST angle throughout the study period and mean fQRST angle was significantly lower at 3- and 6-month follow-up visits compared to baseline values (62° ± 17.4° vs. 57.2° ± 14.8° vs. 50.5° ± 13.6°, p < 0.001 for all dual comparisons). However, despite similar antihyperglycemic effect with empagliflozin treatment in patients with and without CVD, the significant decrease in the mean fQRST angle was observed only in patients with CVD and no significant decrease was observed in the mean fQRST angle in patients without CVD.

WHAT IS NEW AND CONCLUSION

Empagliflozin leads a significant narrowing in the fQRST angle in type 2 DM patients with known CVD.

Combined Effects of Age and Comorbidities on Electrocardiographic Parameters in a Large Non-Selected Population

Background: Previous studies have evaluated average electrocardiographic (ECG) values in healthy subjects or specific subpopulations. However, none have evaluated ECG average values in not selected populations, so we examined ECG changes with respect to age and sex in a large primary population. Methods: From digitized ECG stored from 2008 to 2021 in the Modena province, 130,471 patients were enrolled. Heart rate, P, QRS and T wave axis, P, QRS and T wave duration, PR interval, QTc, and frontal QRS-T angle were evaluated. Results: All ECG parameters showed a dependence on age, but only some of them with a straight-line correlation: QRS axis (p < 0.001, R2 = 0.991, r = 0.996), PR interval (p < 0.001, R2 = 0.978, r = 0.989), QTc (p < 0.001, R2 = 0.935, r = 0.967), and, in over 51.5 years old, QRS-T angle (p < 0.001, R2 = 0.979, r = 0.956). Differences between females and males and in different clinical settings were observed. Conclusions: ECG changes with ageing are explainable by intrinsic modifications of the heart and thorax and with the appearance of cardiovascular diseases and comorbidities. Age-related reference values were computed and applicable in clinical practice. Significant deviations from mean values and from Z-scores should be investigated.

The impact of midazolam used in cataract surgery sedation on frontal QRS-T angle

WHAT IS KNOWN AND OBJECTIVE

Midazolam is one of the most commonly used drugs in procedures requiring sedoanalgesia. It affects the myocardium's ventricular depolarization and repolarization. Previous studies examining the arrhythmogenic effects of midazolam yielded conclusive results. These studies are based on QT and Tp -e distances. The frontal QRS-T angle (f-[QRS-T]a) is a new electro cardiac parameter that shows the heterogeneity of ventricular electrical activity. This study aims to examine the effect of midazolam on f-(QRS- T)a and other depolarization-repolarization parameters in patients who have had cataract surgery.

METHODS

The study included 177 patients administered midazolam as a sedoanalgesia during cataract surgery. The sedative effect was evaluated 2-3 minutes after a 0.05 mg/kg dose of midazolam was given. Sedation was assessed again by giving 0.5 mg every 2-3 minutes until the desired level of sedation was achieved. 12-lead electrocardiogram (ECG) recordings of all patients were taken just before and immediately after surgery. ECGs were used to calculate the QT interval, QTc interval, Tp -e interval, Tp -e/QT, Tp -e/ QTc ratios and f-(QRS-T)a.

RESULTS AND DISCUSSION

After cataract surgery, f-(QRS-T)a was unchanged compared to presurgery (29.14 ± 4.52 vs. 29.18 ± 5.39, p = 0.852). In addition, no significant change in QT(351.32 ± 21.98 vs. 351.94 ± 22.44, p = 0.091), QTc (384.05 ± 24.52 vs. 385.19 ± 26.12, p = 0.819), Tp -e interval (93.12 ± 9.60 vs. 94.44 ± 8.82, p = 0.179) and Tp -e/QT (0.27 ± 0.02 vs. 0.28 ± 0.03, p = 0.664), Tp -e/ QTc ratios (0.28 ± 0.02 vs. 0.29 ± 0.03, p = 0.655) was observed after surgery when compared to presurgery values. Significant ventricular and supraventricular arrhythmias were not observed in any patient during the operation.

WHAT IS NEW AND CONCLUSION

Midazolam did not affect f -(QRS-T) with classical repolarization parameters in patients who underwent cataract surgery, according to this study. Midazolam has been found to be safe for the heart in sedoanalgesia. These results show that sedation with midazolam can be performed without electrocardiogram monitoring.

Heat Shock Protein 27 Levels Predict Myocardial Inhomogeneities in Hemodialysis Patients

Background

Sudden cardiac death (SCD) is the single major cause of death in hemodialysis (HD) patients. QRS-T angle is an established marker of global repolarization heterogeneity associated with electrical instability and SCD. Heat shock protein 27 (HSP27) plays an important, protective role against noxious factors in the cardiovascular (CV) system. This study is aimed at assessing whether low HSP27 is associated with myocardial inhomogeneities in HD patients, as expressed by increases in the spatial QRS-T angle.

Methods

Clinical data and biochemical, echocardiographic, and electrocardiographic parameters were evaluated in 182 HD patients. Patients were split into normal and abnormal QRS-T angle groups.

Results

Patients with abnormally high QRS-T angles were older and had higher prevalence of diabetes as well as myocardial infarction, higher left ventricular mass index (LVMI) and C-reactive protein, worse oxidant/antioxidant status, and lower ejection fraction and HSP27. Multiple regression analysis revealed that abnormal QRS-T values were independently, negatively associated with serum HSP27 and positively associated with LVMI.

Conclusions

Low HSP27 levels are associated with increased heterogeneity of myocardial action potential, as expressed by increased spatial QRS-T angle.

Comparison of frontal QRS-T angle in patients with schizophrenia and healthy volunteers

Cardiovascular diseases are the most prominent cause of death in patients with schizophrenia. Frontal QRS-T (fQRS-T) angle is a novel marker of myocardial depolarization and repolarization heterogeneity. Recent studies have indicated that the fQRS-T angle is associated with some cardiovascular abnormalities. This study aimed to investigate the fQRS-T angle and its relationship with symptoms severity in patients with schizophrenia. One hundred-six patients with schizophrenia and sixty-four healthy controls were included in this study. fQRS-T angle and QT interval measurements were calculated for each participant from the automatic report of the 12-lead electrocardiography (ECG) device. The Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I) and The Positive and Negative Syndrome Scale (PANSS) were performed on the patients with schizophrenia. Corrected QT (QTc) interval and fQRS-T angle were significantly higher in the patients with schizophrenia than healthy controls (p < 0.001 and p < 0.001, respectively). fQRS-T angle was positively correlated with age (r = 0.43), duration of disease (r = 0.37), and negative symptoms scores (r = 0.39). In linear regression analysis, the disease duration and negative symptom severity were the independent predictors of fQRS-T angle in patients with schizophrenia (t = 3.730, p = 0.003 and t = 2.257, p = 0.023, respectively). The fQRS-T angle may be an important ECG parameter to interpret cardiovascular disease risk in patients with schizophrenia.

Electrocardiogram-Based Heart Age Estimation by a Deep Learning Model Provides More Information on the Incidence of Cardiovascular Disorders

Objective

The biological age progression of the heart varies from person to person. We developed a deep learning model (DLM) to predict the biological age via ECG to explore its contribution to future cardiovascular diseases (CVDs).

Methods

There were 71,741 cases ranging from 20 to 80 years old recruited from the health examination center. The development set used 32,707 cases to train the DLM for estimating the ECG-age, and 8,295 cases were used as the tuning set. The validation set included 30,469 ECGs to follow the outcomes, including all-cause mortality, cardiovascular-cause mortality, heart failure (HF), diabetes mellitus (DM), chronic kidney disease (CKD), acute myocardial infarction (AMI), stroke (STK), coronary artery disease (CAD), atrial fibrillation (AF), and hypertension (HTN). Two independent external validation sets (SaMi-Trop and CODE15) were also used to validate our DLM.

Results

The mean absolute errors of chronologic age and ECG-age was 6.899 years (r = 0.822). The higher difference between ECG-age and chronological age was related to more comorbidities and abnormal ECG rhythm. The cases with the difference of more than 7 years had higher risk on the all-cause mortality [hazard ratio (HR): 1.61, 95% CI: 1.23–2.12], CV-cause mortality (HR: 3.49, 95% CI: 1.74–7.01), HF (HR: 2.79, 95% CI: 2.25–3.45), DM (HR: 1.70, 95% CI: 1.53–1.89), CKD (HR: 1.67, 95% CI: 1.41–1.97), AMI (HR: 1.76, 95% CI: 1.20–2.57), STK (HR: 1.65, 95% CI: 1.42–1.92), CAD (HR: 1.24, 95% CI: 1.12–1.37), AF (HR: 2.38, 95% CI: 1.86–3.04), and HTN (HR: 1.67, 95% CI: 1.51–1.85). The external validation sets also validated that an ECG-age >7 years compare to chronologic age had 3.16-fold risk (95% CI: 1.72–5.78) and 1.59-fold risk (95% CI: 1.45–1.74) on all-cause mortality in SaMi-Trop and CODE15 cohorts. The ECG-age significantly contributed additional information on heart failure, stroke, coronary artery disease, and atrial fibrillation predictions after considering all the known risk factors.

Conclusions

The ECG-age estimated via DLM provides additional information for CVD incidence. Older ECG-age is correlated with not only on mortality but also on other CVDs compared with chronological age.

The role of metabolic syndrome in sudden cardiac death risk: Recent evidence and future directions

Metabolic syndrome (MetS) is a frequent condition whose deleterious effects on the cardiovascular system are often underestimated. MetS is nowadays considered a real pandemic with an estimated prevalence of 25% in general population. Individuals with MetS are at high risk of sudden cardiac death (SCD) as this condition accounts for 50% of all cardiac deaths in such a population. Of interest, recent studies demonstrated that individuals with MetS show 70% increased risk of SCD even without previous history of coronary heart disease (CHD). However, little is known about the interplay between the two conditions. MetS is a complex disease determined by genetic predisposition, unhealthy lifestyle and ageing with deleterious effects on different organs. MetS components trigger a systemic chronic low-grade pro-inflammatory state, associated with excess of sympathetic activity, cardiac hypertrophy, arrhythmias and atherosclerosis. Thus, MetS has an important burden on the cardiovascular system as demonstrated by both preclinical and clinical evidence. The aim of this review is to summarize recent evidence concerning the association between MetS and SCD, showing possible common aetiological processes, and to indicate prospective for future studies and therapeutic targets.

Prognostic significance of QRS distortion and frontal QRS-T angle in patients with ST-elevation myocardial infarction

BACKGROUND

QRS distortion (G3I) and frontal QRS-T angle (fQRS-T angle) are both electrocardiographic (ECG) signs of ongoing ischemia and depolarization-repolarization heterogeneity, which always occur in patients with ST-segment elevation acute myocardial infarction (STEMI).

METHODS

We retrospectively collected 592 STEMI patients who underwent coronary angiography and follow-up for 42 months. 1. We divided the patients into two groups according to whether they had G3I on admission, compared the differences in examination data and endpoint events between these two groups. 2. Group patients according to whether the endpoint events happened in hospital, at 12 and 42 months, compare whether there is a difference in fQRS-T angle at the same time point, and find out the predictive cutoff value of all-cause death. 3. Combined G3I and fQRS-T angle together to enhance the predictive value.

RESULTS

G3I and fQRS-T angle are both independent risk factors for all-cause death in STEMI patients within 12 months (G3I P = 0.014, fQRS-T angle P < 0.001) and within 42 months (P < 0.001). The cutoff values of fQRS-T angle for predicting all-cause death are 66.5° at 12 months and 90.5° at 42 months. When G3I and fQRS-T angle are combined used to predict the mortality, the specificity is significantly improved, but the sensitivity decreased.

CONCLUSIONS

G3I and fQRS-T angles are valuable in the prognostic assessment of STEMI patients, especially when combined. These findings help clinicians to identify high-risk patients early for more aggressive treatment.

Association between T wave morphology parameters and abnormal cardiac SPECT imaging

BACKGROUND

T-wave morphology dispersion (TMD) described the electrocardiographic T-wave heterogeneity during a single cardiac cycle. Total cosine R-to-T (TCRT) is the average of the cosines of the angles between the QRS and T vectors on the ECG. We examine the predictive value of TMD and TCRT calculation to assess abnormal myocardial perfusion.

METHODS

Retrospective single center cohort study including all patients referred for evaluation of ischemia by myocardial SPECT scanning with no known history of ischemic heart disease, from 1 January 2019 to 31 December 2019. Study endpoint was the correlation between the calculated TMD and TCRT values and detection of myocardial injury or ischemia by myocardial SPECT.

RESULTS

Among 606 patients, calculated TCRT was 0.401 ± 0.53 for the normal group and 0.283 ± 0.62 for the abnormal group (p = 0.007). Measured TMD was 22.9 ± 16.6 degrees (p < 0.001) in the normal group, compared to 31.5 ± 22.8 degrees (p < 0.001) for the abnormal group.

CONCLUSIONS

The results demonstrate a correlation between the decreased TCRT values and increase TMD and myocardial ischemia seen in SPECT results. The TCRT and TMD can be used as simple and non-invasive markers to predict abnormal SPECT results and ischemic heart disease in patients with no known cardiac history.