The Relationship between Body Mass Index and Frontal QRS-T Angle in Pregnant Women Undergoing Cesarean Section with Spinal Anesthesia.

Background and objectives: The frontal QRS-T angle is a novel parameter of myocardial repolarization. Weight gain during pregnancy and physiological changes during a cesarian section may affect the frontal QRS-T angle. We aimed to assess the effect of body mass index (BMI) on the frontal QRS-T angle in pregnant women undergoing cesarean section with spinal anesthesia. Method and materials: This study included 90 pregnant women. BMI was calculated for all pregnant women. The study population was divided into two groups: BMI < 30 (n = 66) and BMI ≥ 30 (n = 24). QT interval measurements and the frontal QRS-T angle were obtained from the report of an electrocardiography machine. Results: It was found that the pre-operative and post-operative frontal QRS-T angle (p = 0.045 and p = 0.007) and QTc interval (p = 0.037 and p < 0.001) were higher in pregnant women with a BMI ≥ 30 than in pregnant women with a BMI < 30. In addition, when compared to pre-operative values, the post-operative frontal QRS-T angle (from 24.0 [20.0-41.5] to 34.5 [19.5-50.0], p = 0.031) and QTc interval (from 420.6 ± 13.3 to 431.7 ± 18.3, p = 0.010) were increased in the BMI ≥ 30 group, whereas no significant post-operative increase was observed in the BMI < 30 group. In correlation analysis, BMI was positively correlated with the frontal QRS-T angle and QTc interval. Conclusions: The frontal QRS-T angle and QTc interval were importantly increased in pregnant women with a BMI ≥ 30 than in pregnant women with a BMI < 30. Also, after cesarean section operation with spinal anesthesia, the frontal QRS-T angle and QTc were increased significantly in the BMI ≥ 30 group, whereas no significant change was observed in the BMI < 30 group. Therefore, it is suggested to perform close post-operative monitoring in pregnant women with a BMI ≥ 30 undergoing cesarean section with spinal anesthesia.

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.

Electrocardiographic frontal QRS-T angle is independently associated with panic disorder.

OBJECTIVE: Panic disorder (PD) may cause serious cardiac arrhythmias by causing electrical abnormalities. Abnormal P-wave axis (aPwa), presence of fragmented QRS (fQRS), wide frontal QRS-T angle (fQRSTa), QRS duration corrected (QRSdc) and log/ logQRS duration/RR interval (log/logQRS/RR) have been correlated with increased risk of serious supraventricular and ventricular cardiac arrhythmias in a general population. The purpose of this study was to compare these newly explored atrial and ventricular arrhythmia indicators in patients with PD and in healthy subjects. METHOD: A total of 169 newly diagnosed PD patients and 128 healthy subjects were included in the study. The Panic and Agoraphobia Scale (PAS) was administered, and 12-lead electrocardiography (ECG) measurements were obtained. Electrocardiographic parameters including aPwa, fQRSTa, presence of fQRS, QRS duration corrected (QRSdc), and log/logQRS duration/RR distance (log/logQRS/RR) were compared between the two groups. RESULTS: aPwa and fQRS, in addition to fQRSTa, QRSdc, and log/ logQRS/RR ratio values, were significantly increased in the PD group compared to healthy controls. Correlation analyses revealed that wider fQRSTa, number of fQRS derivation, number of total fQRS, wider QRSdc, and log/logQRS/RR ratio significantly correlated with PAS score. Logistic regression analysis demonstrated that fQRSTa and the number of total fQRS were independently associated with PD. CONCLUSION: PD is associated with wider fQRSTa, QRSdc, and log/logQRS/RR in addition to the increased abnormal aPwa and presence of fQRS. These findings suggest that untreated PD patients may be susceptible to supraventricular and ventricular arrhythmia, indicating that ECG should be routinely obtained in the management of PD patients.

Is left bundle branch pacing (LBBP) associated with better depolarization and repolarization kinetics than right ventricular mid septal pacing (RVSP)? - Comparison of frontal QRS -T angle in patients with LBBP, RVSP and normal ventricular conduction.

AIMS: To assess the frontal QRS- T angle (f QRS- T angle) in patients with left bundle branch pacing (LBBP) as compared to right ventricular mid septal pacing (RVSP) implanted for symptomatic high degree atrioventricular (AV) block and to compare with control subjects with normal ventricular conduction (CSNVC) METHODS: A total of one-fifty subjects were chosen (50 patients with LBBP, 50 patients with RVSP and 50 CSNVC). The indication for pacemaker implantation was symptomatic high degree AV block. Baseline clinical and electrocardiogram (ECG) parameters like QRS duration (QRSD), QRS axis and f QRS-T angle and Ejection Fraction (EF) were assessed. f QRS-T angle was measured as the difference between the computerised mean frontal QRS and T wave axes in the limb leads. If the difference between the QRS axis and T-wave axis exceeds 180°, then the resultant QRS-T angle would be calculated as 360° minus the absolute angle to obtain a value between 0° and 180°. Baseline, immediate post procedural and 6 month follow up (f/u) ECGs and EF were chosen for the analysis. RESULTS: Patients who underwent LBBP had significantly shorter paced QRSD than patients who had undergone RVSP (112 ± 12 ms vs 146 ± 13 ms; 95 % confidence interval (CI): 43, -31; p<0.001). There was no significant difference in the QRSD before and after LBBP. The QRSD before and after pacing in RVSP was 111 ± 27 ms and 146 ± 13 ms; 95 % CI: 43, -28; p < 0.001. The QRSD in control patients with NVC was 82.94 ± 9.59 ms. RVSP was associated with wider f QRS-T angle when compared with LBBP (103 ± 53° vs 82 ± 43°; 95 % CI: 39, -1.0; p = 0.037). The baseline and immediate post procedure f QRS-T angle in LBBP was 70 ± 48° and 82 ± 43°; 95 % CI: 31, 5.3; p = 0.2. At 6 months f/u, the f QRS-T angle was 61 ± 43°; 95 % CI: 8.5, 35; p=0.002. The baseline and immediate post procedure f QRS-T angle in RVSP was 67 ± 51° and 103 ± 53°; 95 % CI: 54, -17; p < 0.001. At 6 months f/u, the f QRS-T angle in RVSP group was 87 ± 58°; 95 % CI: 2.6, 29; p = 0.020. The f QRS T angle in control patients with NVC was 24 ± 16°. When subgroup analysis was done the difference in the f QRS-T angle was significant between RVSP and LBBP groups only in patients who had wide QRS escape. The mean LVEF at 6-month follow-up in LBBP vs RVSP was 61 ± 3.7 % vs 57.1 ± 7.8 %; 95 % CI:1.48, 6.32, p = 0.002. In the RVSP group, three patients developed pacing induced cardiomyopathy (PIC) whereas no patients in the LBBP group developed PIC at 6-month follow-up; p=0.021. One patient with PIC had deterioration of functional status with new onset HF symptoms. The patient symptoms improved with medical therapy and needed no hospitalisation. The patient declined further interventions including upgradation to CRT or LBB pacing. No deaths or ventricular arrhythmias were observed during the study period. CONCLUSION: LBBP is associated with narrower f QRS-T angle as compared to RVSP both at post implant period and at 6 month f/u period. These findings might be due to the more physiological depolarization and repolarization kinetics associated with LBBP. RVSP was associated with 6 % incidence of PIC. Hence wide f QRS-T angle might be a predictor of PIC.

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.

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.

Comparison of frontal QRS-T angle of patients with nasal septal deviation with healthy controls.

BACKGROUND: This study compares frontal QRS-T angle (fQRS-T) in electrocardiogram (ECG) examinations of people with nasal septal deviation (NSD) with healthy controls (HC). METHODS: Eighty-two patients whom a radiologist with paranasal computed tomography definitively diagnosed with NSD were included in the study. 101 individuals without NSD were selected as HC. RESULTS: Compared to the HC group, the fQRS-T in was considerably wider in patients with NSD (p < .001). According to Spearman correlation analysis, fQRS-T and NSD angle, and platelet lymphocyte ratio (PLR) were significantly correlated (p = .021, p < .001, and p = .003, respectively). In linear regression analysis where the fQRS-T was taken as a dependent variable, NSD angle and PLR predicted the fQRS-T significantly and positively (F(5.76) = 8.451, R2 = 0.357, Adjusted R2 = 0.315 and p < .001). CONCLUSION: In this study, fQRS-T was significantly higher in patients with NSD. In future studies, fQRS-T can be compared before and after septoplasty in NSD patients.

Frontal Plane QRS-T Angle as a Marker of Cardiac Iron Overload in Patients with Beta Thalassemia Major.

Introduction: Cardiomyopathy due to myocardial iron deposition is the leading cause of death in transfusion- dependent beta-thalassemia major (ß-TM) patients. Although cardiac T2* magnetic resonance imaging (MRI) can be used for the early detection of cardiac iron level before the onset of symptoms associated with iron overload, this expensive method is not widely available in many hospitals. Frontal QRS-T angle is a novel marker of myocardial repolarization and is associated with adverse cardiac outcomes. We aimed to investigate the relationship between cardiac iron load and f(QRS-T) angle in patients with ß-TM. Methods: The study included 95 ß-TM patients. Cardiac T2* values under 20 were considered to indicate cardiac iron overload. The patients were divided into two groups according to the presence or absence of cardiac involvement. Laboratory and electrocardiography parameters, including frontal plane QRS-T angle, were compared between the two groups. Results: Cardiac involvement was detected in 33 (34%) patients. Multivariate analysis showed that frontal QRS-T angle independently predicted cardiac involvement (p < 0.001). An f(QRS-T) angle of ≥ 24.5° had a sensitivity of 78.8% and a specificity of 79% in detecting the presence of cardiac involvement. In addition, a negative correlation was found between cardiac T2* MRI value and f(QRS-T) angle. Conclusions: A widening f(QRS-T) angle could be considered a surrogate marker of MRI T2* to detect cardiac iron overload. Therefore, calculating the f(QRS-T) angle in thalassemia patients is an inexpensive and simple method for detecting the presence of cardiac involvement, especially when cardiac T2* values cannot be determined or monitored.

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.

Relationship Between Index of Cardiac Electrophysiological Balance, Frontal QRS-T Angle and Retinopathy in People with Type 2 Diabetes.

Background: Diabetic retinopathy (DR) is strongly associated with cardiovascular disease, which is a risk factor for sudden cardiac death (SCD). The index of cardiac electrophysiological balance (iCEB) and the frontal QRS-T angle are recommended to predict the risk of ventricular arrhythmias more than other ECG parameters. However, the relationships between these two markers and DR have not yet been explored. The aim of this study was to investigate the variation in the iCEB, corrected iCEB (iCEBc) and frontal QRS-T angle in different stages of DR and determine whether there are associations between these markers and DR. Methods: The sample comprised 665 patients with Type 2 diabetes mellitus (T2DM) who were classified into three groups: no DR (NDR), mild to moderate non-proliferative DR (NPDR), and vision-threatening DR (VTDR). Twelve-lead ECG was performed and the QT, QTc, QRS duration, iCEB, iCEBc and frontal QRS-T angle were recorded and compared across the groups. Results: The VTDR group had a significantly higher iCEBc and frontal QRS-T angle than the NDR and NPDR groups. After controlling for confounding variables, the correlations between the iCEBc (OR=2.217, 95% CI=1.464-3.358, P<0.001), frontal QRS-T angle (OR=1.017, 95% CI=1.008-1.025, P<0.001) and DR risk remained (P<0.05). Subjects in the fourth iCEBc quartile (adjusted OR=2.612, 95% CI=1.411-4.834, p=0.002) had a much higher chance of developing DR compared to those in the first quartile. In comparison to the first frontal QRS-T angle quartile, subjects in the third (adjusted OR=1.998, 95% CI=1.167-3.422, P=0.012) and fourth (adjusted OR=2.430, 95% CI=1.420-4.160, P=0.001) frontal QRS-T angle quartiles had significantly greater risks of DR. Conclusion: With the progression of DR, the iCEBc and frontal QRS-T angle increase. An increased iCEBc and frontal QRS-T angle are associated with an increased risk of DR.

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 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 Relationship Between In-Hospital Mortality and Frontal QRS-T Angle in Patients With COVID-19.

Background Recent studies have demonstrated that the frontal QRS-T angle, defined as the angle between the mean QRS and T vectors, is a strong independent predictor of mortality in patients with cardiovascular disease and in the normal population. In this study, we aimed to investigate the relationship between frontal QRS-T angle and in-hospital mortality in COVID-19 patients. Methods A total of consecutive 532 patients with positive polymerase chain reaction (PCR) tests were enrolled. The patients were divided into two groups as in-hospital mortality and survival groups. Frontal QRS-T angle was automatically calculated from the admission electrocardiography (ECG). Results The median age in the study population was 62 (49-72) years and 273 (51.4%) of the patients were male. The median frontal QRS-T angle was 40 degrees (20-67 IQR) in the in-hospital mortality group, while it was 27 (11-48 IQR) in the survival group (p=0.001). In multivariable logistic regression analysis, frontal QRS-T angle was found to be an independent predictor of mortality (Odds ratio (OR):1.01, 95% Confidence interval (CI):1.00-1.02, p=0.036). Conclusion Frontal QRS-T angle, which was observed wider in the in-hospital mortality group, was found to be associated with in-hospital mortality in patients hospitalized for COVID-19.

The relationship between myocardial bridge and frontal QRS-T angle.

Aim: Although Myocardial bridge (MB) is known as a benign condition, it has been demonstrated to be associated with cardiac arrhythmias and poor outcomes. Frontal QRS-T angle (fQRSTa) is a novel indicator of repolarization and depolarization heterogeneity. Last studies indicated that associated with fQRSTa and adverse cardiac events. No study evaluated the relationship between fQRSTa and MB. In the present study, we aimed to investigate the relationship between MB and fQRSTa. Methods: This study included 91 patients with normal coronary arteries and 89 patients with MB. Coronary angiography was performed in all patients due to ischemia findings on treadmill exercise test or myocardial scintigraphy.2-lead surface electrocardiograms (ECGs) of all patients were evaluated. QT interval, fQRSTa, QTc interval were measured from surface ECGs. Results: Baseline clinical, echocardiographic and laboratory parameters were similar between MB and control group. However, when compared to control group, patients with MB had importantly raised fQRSTa [27 (20-41) vs. 23 (12-37) p = 0.007]. In correlation analysis, fQRSTa was positively correlated with MB length (r = 0.411, p < 0.001). Linear regression analysis showed that MB length was the just considerable predictor of fQRSTa (ß = 0.247, p = 0.041). Conclusions: The fQRSTa is a novel electrocardiographic marker that can be easily obtained from surface ECG. We have shown for the first time that MB length is a significant predictor of fQRSTa.

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: It is known that a wide frontal QRS-T(f[QRS-T]) angle in the electrocardiography (ECG) is associated with poor cardiovascular outcomes. The Tp-e (the interval from the peak to the end of the T wave) interval and Tp-e/QTc ratio show the dispersion of repolarization, and increased levels lead to ventricular arrhythmogenesis in congenital channelopathies and coronary heart disease. In this study, we aimed to investigate the relationship between f(QRS-T), Tp-e interval, and Tp-e/QTc ratio and SYNTAX score in stable coronary artery disease (SCAD) patients. Methods: A total of 403 patients who performed coronary angiography for SCAD were included. The study population was divided into two groups based on the SYNTAX score. Group 1 included 248 patients (high SYNTAX score > 0), and group 2 included 155 patients (low SYNTAX score = 0). SYNTAX score was calculated using an online SYNTAX score calculator from the coronary angiography images of each patient. The f(QRS-T) angle (QRS angle minus T angle) was calculated from the automated reports of the 12-lead ECG device. Tp-e interval and Tp-e/QTc ratio and other electrocardiographic parameters were recorded. Results: The mean SYNTAX score in group 1 was 8. F(QRS-T) angle, Tp-e duration, Tp-e/QT, and Tp-e/QTc were significantly higher in group 1 compared with group 2. In the multivariate regression analysis, F(QRS-T) angle and Tp-e duration were independent predictors for SYNTAX scores in SCAD patients. Conclusions: Our study showed that Tp-e interval, Tp-e/QTc ratio, and f(QRS-T) angle were increased in patients with higher SYNTAX scores in patients with SCAD patients.

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.

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.

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.