Plane QRS-T Angle Research Articles

The effect of dapagliflozin therapy on ventricular repolarization parameters in electrocardiography in patients with diabetic cardiovascular disease

BackgroundDapagliflozin is an agent that has both antihyperglycemic effects and is significantly associated with a lower risk of cardiovascular events in patients with diabetes mellitus (DM). However, there is insufficient data and information about the effect of dapagliflozin on electrocardiographic (ECG) parameters. AimThe effects of dapagliflozin on ventricular repolarization parameters have not been fully elucidated yet. This study aimed to investigate whether dapagliflozin has a positive effect on ventricular repolarization heterogeneity parameters in patients with type 2 DM. MethodWe retrospectively enrolled 140 patients with a known diagnosis of type 2 DM who were newly prescribed dapagliflozin in addition to standard anti-diabetic therapy. The patients were divided into two groups according to whether they had cardiovascular disease (CVD). The effect of dapagliflozin treatment on ventricular repolarization parameters (frontal plane QRST angle, Tp-e interval, Tp-e/QTc, QTc, and QTc dispersion) was investigated, patient groups were compared before and after treatment. ResultsAmong 140 patients, 70 (50 %) had CVD and 70 (50 %) did not have CVD. Dapagliflozin treatment resulted in significant reductions in ventricular repolarization parameters over the study period in the CVD group with diabetes. Mean fQRST angle, Tp-e interval, Tp-e/QTc, QTc, and QTc dispersion were significantly lower than baseline values at 6-month follow-up visits in the CVD group (61.61 ± 9.22° vs 52.55 ± 8.31°, 74.45 ± 16.06 msec vs 63.27 ± 13.99 msec, 0.19 ± 0.03 vs 0.16 ± 0.03, 384.12 ± 47.93 msec vs 356.15 ± 43.31 mesc, 55.28 ± 5.50 msec vs 48.08 ± 6.48 msec for all pairwise comparisons p < 0.001). ConclusionSimilar antihyperglycemic effects were found with dapagliflozin treatment in patients with and without CVD. However, significant reductions in ventricular repolarization parameters were observed only in patients with CVD.

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

Cardiomyopathy due to myocardial iron deposition is the leading cause of death in transfusion- dependent beta-thalassemia major (β-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 β-TM. The study included 95 β-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. 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. 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.

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

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. 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 underwentan 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. A total of 162 patients, comprising 68 women (41.9%) and94 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). 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.

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.

Investigation of the relationship of frontal QRS-T angle and digoxin use and blood digoxin level

Objectives: Digoxin is an antiarrhythmic drug with a narrow therapeutic range and used in clinical conditions such as heart failure and atrial fibrillation. The planar frontal QRS-T angle reflects the deviations between the depolarization and repolarization of the ventricles, and it has been reported that an increase in this angle is associated with an increase in mortality. In our study, the relationship between frontal QRS-T angle and digoxin use and blood digoxin level was investigated. Methods: The study included 105 digoxin users who used digoxin, whose levels were measured, who had an electrocardiogram (ECG) on the system, and 15 patients with similar characteristics, who had an ECG and did not use digoxin. Patients using digoxin and whose levels were measured were also divided into three groups as &amp;lt; 0.8 ng/mL, 0.8-1.2 ng/mL, and &amp;gt; 1.2 ng/mL. The absolute value of the value obtained by subtracting the axis of the T wave from the axis of the QRS angle indicated on the paper, calculated automatically on the 12-lead ECG, was accepted as the frontal QRS-T angle value. Results: Planar frontal QRS-T angle measured by 12-lead ECG in digoxin users was 120º (55.5º-155.5º), while it was 106º (32º-163º) in non-users, and there was no statistical difference between the two groups (p = 0.833). In the evaluation made according to different blood drug levels as &amp;lt; 0.8 ng/mL, 0.8-1.2 ng/mL, &amp;gt; 1.2 ng/mL in digoxin users, no significant difference was observed between the frontal QRS-T angle between the groups (109.5° [60.25°-154.25°] for &amp;lt; 0.8 ng/mL, 136.5° [48.5°-158.5°] for 0.8-1.2 ng/mL, 117° [34°-154°] for 1.2 ng/mL) (p = 0.773).Conclusions: There was no significant difference in frontal QRS-T angle between digoxin users and non-users. There was no significant relationship between different blood digoxin levels and frontal QRS-T angle.

Frontal QRS-T Açısı İle Ambulatuar 24 Saat Holterde Prematür Ventriküler Kontraksiyon Yükü Arasındaki İlişki

Aim: Frequent premature ventricular contractions (PVCs) can cause impaired ventricular function or dilatation of ventricular cavities. The frontal plane QRS-T [f(QRS-T)] angle is an indicator of instability in the electrophysiological properties of the myocardium and is associated with arrhythmias. The present study aimed to investigate whether f(QRS-T) angle, as a marker of ventricular repolarization heterogeneity, predicts premature ventricular contraction burden in ambulatory 24-hour Holter.Methods: The study included 100 patients. The patients were divided into two groups as ‘frequent PVC’ and ‘seldom PVC’ according to their PVC burden in 24-hour Holter monitoring. Laboratory and some ambulatory electrocardiography parameters, including frontal plane QRS-T angle, were compared between the two groups.Results: Frontal QRS-T angle (63.34±37.86° vs 23.46±14.29° p&amp;lt;0.001) was found to be wider in the Frequent PVC group. F(QRS-T) angle of ≥ 34° had a sensitivity of 82.2% and a specificity of 80% in indicating PVC load (AUC: 0.887 (0.824-0.950). In addition, a positive correlation was found between PVC burden and f(QRS-T) angle (r:0.429 p&amp;lt;0.001).Conclusion: The widening of f(QRS-T) angle could perhaps be considered as a surrogate marker of increased PVC burden in 24-hour Holter monitoring. Measuring f(QRS-T) angle in 12-lead ECG in patients with PVC may be a warning sign for increased PVC burden.

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

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

Covid-19 survivors may have deterioration in frontal plane qrs-t angle and the other electrocardiogram parameters

Funding AcknowledgementsType of funding sources: None.BackgroundCOVID-19 infection is known to damage myocardial tissue and increase arrhythmic events. However, the data in the literature on permanent attachments are limited. In our study, we planned to investigate possible arrhythmic damages in COVID-19 survivors using the frontal plane QRS-T [f(QRS)‐T] angle and some other ECG parameters.Patients & Methods269 patients who recovered from COVID-19 between April 2020 and January 2021 were included into the study. Pre-admission electrocardiograms and first-month outpatient clinic control ECGs of the patients were compared.ResultsAfter COVID-19, left bundle branch block (p<0.001), right bundle branch block (p<0.001), right bundle branch block (p<0.001), atrial fibrillation (p<0.001) rates had increased. Prolongation was detected in QRS duration (p<0.001), QT interval (p=0.014), adjusted QT interval (p =0.007) and Tpe interval (p=0.012). F(QRS)‐T angle (p<0.001) and fragmented QRS rate (p<0.001) were increased.ConclusionsIt was observed in our study that; even if patients survive after COVID-19, permanent deterioration in ECG parameters may occur.

Pediatric T-wave memory after accessory pathway ablation in Wolff-Parkinson-White syndrome.

Altered ventricular depolarization due to manifest accessory pathway conduction (ie, Wolff-Parkinson-White syndrome) leads to repolarization abnormalities that persist after pathway ablation. The term T-wave memory (TWM) has been applied to these changes, as the postablation T-wave vector "remembers" the pre-excited QRS vector. In adults, these abnormalities can be misinterpreted as ischemia leading to unnecessary interventions. To date, no comprehensive studies have evaluated this phenomenon in the pediatric population. The purpose of this study was to define TWM in the pediatric population, identify preablation risk factors, and delineate the timeline of recovery. Pre- and postablation electrocardiograms (ECGs) in patients ≤25 years were analyzed over a 5-year period. Frontal plane QTc interval, T-wave axis, QRST angle, and T-wave inversions were used to identify patients with TWM. Univariate analysis was performed to determine the association of preablation ECG features with the outcome of TWM. TWM was present in 42% of pediatric patients, with resolution occurring within 3 months of ablation. Preablation QRS axis <0° was a strong predictor of TWM (odds ratio [OR] 15.2; 95% confidence interval [CI] 5.7-40), followed by posteroseptal pathway location (right posteroseptal-OR 8.9; 95% CI 4.2-18.8; left posteroseptal-OR 6.1; 95% CI 1.7-22.3). The degree of pre-excitation had a modest association with the development of TWM. No adverse events were observed. TWM is less common in children compared to adults, and normalization occurred within 3 months postablation. The most predictive features for the development of TWM include a leftward pre-excited QRS axis and posteroseptal pathway location.

The role of ECG as a mortality predictor in COVID-19 patients treated in the intensive care unit

Background: COVID-19 infection has reached serious morbidity and mortality rates all over the world for a short time. Many studies have investigated the relationship of COVID-19 disease with mortality and morbidity. In this study, we wanted to elucidate the relationship between rhythm character (sinus rhythm vs atrial fibrillation) and QTc and frontal plane QRS-T angle, which parameters are reflecting the depolarization-repolarization kinetics, and mortality, which were not emphasized enough in previous studies.&#x0D; Material and Method: 259 patients admitted to the intensive care unit due to COVID-19 infection between 01.04.2020 and 01.12.2020 was included in the study. The demographic characteristics of the patients, clinical backgrounds, laboratory values ​​at the time of admission to the intensive care unit, and 12 derivation ECG records were obtained from the patient files. Rhythm, PR distance, QRS duration and morphology, QT interval, T wave morphology, presence of atrioventricular (AV) block, QRS axis, presence of ventricular premature contraction, frontal plane QRS-T (f(QRS-T)) angle degree were determined on 12 derivation ECG records. Patient groups were classified as "deceased patient" and "survivors" and the relationship of these parameters with survival was tried to be elucidated.&#x0D; Results: the frequency of atrial fibrillation was significantly higher in the "deceased patient" group. For patients in sinus rhythm, there was no difference between the two groups in terms of PR distance and 1st degree AV block. Severe AV block was not observed in either group. There was no difference between the two groups in terms of QRS morphology, T wave inversion, and ventricular premature contractions. QRS duration, corrected QTc duration, and frotal plane QRS-T angle values ​​were found to be statistically significantly higher in in the "deceased patient" group.&#x0D; Conclusion: Atrial fibrillation, prolonged QTc duration and increased frontal plane QRS-T angle can be considered as mortality predictors in COVID-19 infection whose mortality rate is high all over the world.

Frontal plane QRS-T angle predicts early recurrence of acute atrial fibrillation after successful pharmacological cardioversion with intravenous amiodarone.

Although restoration of sinus rhythm is the integral part of the atrial fibrillation (Af) management, recurrence frequency of Af is high after cardioversion. However, little is known about the association of electrocardiography (ECG) parameters with Af recurrence after restoration of sinus rhythm. The present study aimed to investigate whether frontal plane QRS-T (fQRST) angle, as a marker of ventricular repolarization heterogeneity, predicts Af recurrence after successful pharmacological cardioversion. One hundred and sixty-five paroxysmal Af patients with an acute Af episode who underwent successful pharmacological cardioversion with intravenous amiodarone infusion were included into the study. Patients were divided into two groups according to presence or absence of in-hospital Af recurrence. The association between fQRST angle and Af recurrence was investigated. Af recurrence was observed in 42 (25.4%) patients. The mean fQRST angle was significantly higher in patients with Af recurrence compared to those without Af recurrence (90±45.8 vs. 51±38.2, p<0.001). Also, Af recurrence was more frequent in patients who had fQRST angle >90˚, compared to patients with fQRST angle ≤90˚ (54.1% vs. 13.7%, p<0.001). Moreover, ROC curve analysis demonstrated that an increased fQRST angle >92.5˚ predicted in-hospital Af recurrence with a sensitivity of 76.2% and a specificity of 81.4% (AUC:0.728, p<0.001). Furthermore, multivariate analysis demonstrated that fQRST angle was an independent predictor of in-hospital Af recurrence after successful pharmacological cardioversion (OR: 1.892, 95% CI: 1.361-2.917, p<0.001). As a parameter that can be easily calculated from automated ECG recordings, fQRST angle may be useful in the prediction of early Af recurrence after successful pharmacological cardioversion with amiodarone.

Relationship between morning blood pressure surge and the frontal plane QRS-T angle in newly diagnosed hypertensive patients

ABSTRACT Background Morning blood pressure surge (MBPS) plays an important role in target organ damage and major adverse cardiac events. The frontal QRS-T [f(QRS-T)] angle is the electrocardiographic marker and index of ventricular arrhythmogenic events. We aimed to investigate the relationship between MBPS and the f(QRS-T) angle, which is an indicator of ventricular repolarization disorder, in patients with newly diagnosed HT. Methods Between June 2020 and March 2021, 263 patients with newly diagnosed HT who were admitted to our outpatient clinic were prospectively included in the study. According to ambulatory blood pressure monitoring (ABPM), the patients were categorized into two groups: Group-I: low-value MBPS (<37 mm Hg), and group-II: high-value MBPS (≥37 mm Hg). The f(QRS-T) angle calculated from the 12-lead electrocardiogram and all other data were compared between the groups. Results A total of 186 newly diagnosed HT patients who met the inclusion criteria were included in the study. The average f(QRS-T) angle in Groups I and 2 was 21° ± 16° and 51° ± 30°, respectively (P < .001). According to multivariate regression analysis, T peak-end and MBPS were found to be independent predictors of the f(QRS-T) angle. Conclusions As a result of our study, we found that the f(QRS-T) angle was widened in patients with exaggerated MBPS. The cause of increased cardiovascular outcomes in patients with exaggerated MBPS may be explained by widened in the f(QRS-T) angle that is a ventricular repolarization parameter.

Electrocardiographic differences in patients with true and pseudo-resistant hypertension.

Cardiovascular disease is the leading cause of mortality in hypertensives, and patients with true resistant hypertension have an increased risk for premature cardiovascular events. Electrocardiography (ECG) has an essential role in the monitoring of hypertensive heart disease; however, little is known about the importance of ECG parameters in patients with resistant hypertension. We aimed to investigate whether fragmented QRS (fQRS) and frontal plane QRS-T angle, which are novel ECG parameters indicating myocardial damage, predict true resistant hypertension in patients with uncontrolled blood pressure. Four hundred six hypertensive patients with resistant hypertension were prospectively enrolled for the study. Patients were divided into two groups as 'true resistant' or 'pseudo-resistant' hypertensives and compared regarding the ECG parameters. While 73 (18%) patients had true resistant hypertension, 333 (82%) patients had pseudo-resistant hypertension. The frequency of fQRS (47.9% vs. 20.1%, p < 0.001) and average frontal plane QRS-T angle (93.0° ± 19.7° vs. 53.8° ± 10.2°, p < 0.001) were significantly higher in patients with true resistant hypertension compared to those with pseudo-resistant hypertension. Also, fQRS in anterior leads was significantly more frequent in patients with true resistant hypertension (57.1% vs. 23.8%, p < 0.001). Moreover, ROC curve analysis demonstrated that an increased frontal plane QRS-T angle > 90.75° predicted true resistant hypertension with a sensitivity 96% and specificity 61% (AUC:0.874, p < 0.001). Furthermore, multivariate analysis demonstrated that fQRS in anterior leads (OR: 1.251, 95% CI: 1.174-1.778, p = 0.002) and frontal plane QRS-T angle (OR: 1.388, 95% CI: 1.073-1.912, p < 0.001) were independent predictors of true resistant hypertension. In conclusion, fQRS and frontal plane QRS-T angle may be useful to predict true resistant hypertension in patients with uncontrolled blood pressure.

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

Frontal plane QRS-T (fQRS-T) angle is a marker of ventricular repolarization heterogeneity and increased fQRS-T angle is associated with arrhythmias, adverse events and mortality. However, little is known about the importance and usefulness of fQRS-T angle in hypertensive patients. The present study aimed to investigate the association between blood pressure (BP) levels and fQRS-T angle. The main goal was to demonstrate whether BP lowering has a favorable effect on fQRS-T angle in hypertensive patients. This study included 392 newly diagnosed hypertensive patients who underwent antihypertensive therapy. Responders and nonresponders to antihypertensive therapy were compared regarding baseline and post-treatment fQRS-T angle. fQRS-T angle was calculated as the absolute difference between QRS and T wave axes that were obtained from electrocardiography. Response to treatment was defined as achieving BP levels <140/90 mmHg. At the 1-month follow-up visit, responders had significantly lower fQRS-T angle compared to nonresponders despite the similar baseline fQRS-T angle (baseline: 57° ± 18.2° vs.56.6° ± 16.3°; P = 0.819, at 1 month: 36.9° ± 13.7 vs.53.5° ± 15.6°; P < 0.001). Moreover, after 3 months of antihypertensive treatment, both responders at 1 month and 3 months had significantly lower fQRS-T angle compared to nonresponders (34.8° ± 13.3° vs. 35.4° ± 12.9° vs. 52.3° ± 13.9°; P < 0.001). Furthermore, a significant moderate positive correlation was observed between systolic BP and fQRS-T angle (r:0.797; P < 0.001), and between diastolic BP and fQRS-T angle (r:0.761; P < 0.001). In the present study, a significant decrease in fQRS-T angle was observed following BP lowering throughout the study period. Therefore, fQRS-T angle may be useful in the monitoring of antihypertensive treatment.

The frontal plane QRS-T angle may affect our perspective on prehypertension: A prospective study

ABSTRACT Backround The frontal plane QRS-T [f(QRS-T)] angle is an easy marker of myocardial repolarization and was associated with adverse cardiovascular outcomes like prehypertension (PHT). This study was aimed to investigate to evaluate the f(QRS-T) angle in patients with PHT. Methods We measured f(QRS-T) angle of 70 subjects with PHT, 109 patients with hypertension (HT), and 102 normotensive healthy volunteers. The f(QRS-T) angle was calculated from 12-lead electrocardiography. Results The f(QRS-T) angle was significantly higher in the HT and PHT groups as compared to the control group, but there was no significant difference in the f(QRS-T) angle between the HT and PHT groups. The f(QRS-T) angle was significantly and positively correlated with age, systolic blood pressure (BP) in 24 hours, average BP in 24 hours, pulse pressure in 24 hours, hemoglobin, QT dispersion, TpE distance while was negatively correlated with left ventricular ejection fraction. In multivariable analysis, we showed that systolic BP, average BP in 24 hours, pulse pressure in 24 hours, hemoglobin, QT dispersion, Tpe distance were independent predictors of higher f(QRS-T) angle. Conclusions The f(QRS-T) angle, a noninvasive measurement analyzing the dysfunction in cardiac conduction system, was increased in subjects with PHT as compared to normotensives, and the subjects with PHT had f(QRS-T) angle as higher as patients with HT did. Our findings are supportive for the hypothesis that disturbances in ventricular repolarization is present in an early stage of essential hypertension.

Frontal plane QRS-T angle in the monitoring of intravenous amiodarone infusion for pharmacological cardioversion of acute atrial fibrillation.

Intravenous amiodarone infusion is effective and widely used treatment for pharmacological cardioversion of recent-onset atrial fibrillation (Af). Although amiodarone may trigger various alterations in cardiac electrophysiology and electrocardiography (ECG), the impact of amiodarone treatment on frontal plane QRS-T angle remains unclear. Frontal plane QRS-T angle is the angle between the depolarization and repolarization axes and indicates instability in the cardiac cellular electrophysiology. Therefore, the present study aimed to investigate whether intravenous amiodarone infusion has effect on frontal plane QRS-T angle in patients with acute Af. A total of 179 patients with acute-onset Af who underwent pharmacological cardioversion with intravenous amiodarone infusion were included into the study. Patients with successful and failed pharmacological cardioversion were compared regarding pre- and post-treatment frontal plane QRS-T angle. At the end of the amiodarone infusion, sinus rhythm was restored in 112 (62.6%) patients, whereas Af was persisted in 67 (37.4%) patients. Despite the similar frontal plane QRS-T angle at baseline (59.6°±21.73°vs.60.4°±25.67°, p=0.822), patients with failed pharmacological cardioversion had significantly higher post-treatment frontal plane QRS-T angle compared to patients with successful pharmacological cardioversion (68.8°±21.71°vs.58.6°±25.15° p<0.001). Furthermore, multivariate analysis demonstrated that post-treatment increased frontal plane QRS-T angle was found to be an independent predictor of failure of pharmacological cardioversion with amiodarone infusion (OR:1.233, 95% CI:1.147-1.919, p=0.024). Amiodarone may significantly affect the frontal plane QRS-T angle. As a parameter that can be easily calculated from automated ECG recordings, frontal plane QRS-T angle may be useful in the monitoring of intravenous amiodarone treatment.

Frontal plane QRS-T angle may be a predictor for post-coronary artery bypass graft surgery atrial fibrillation

New-onset postoperative atrial fibrillation (POAF) is the most common arrhythmia following coronary artery bypass graft surgery (CABG) and is associated with prolonged hospitalization, stroke, and mortality. The frontal plane QRS-T [f(QRS-T)] angle, which is defined as the angle between the directions of ventricular depolarization (QRS-axis) and repolarization (T-axis), is a novel marker of ventricular repolarization heterogeneity. The f(QRS-T) angle is associated with adverse cardiac outcomes. In light of these findings, in this study, we aimed to investigate the potential relationship between the f(QRS-T) angle and POAF. 180 patients who underwent CABG between August 2017 and September 2018 were included in the study retrospectively. Two groups were established as patients who preserved postoperative sinus rhythm (n=130) and those who developed POAF (n=50). The f(QRS-T) angle and all other data were compared between groups. The fF(QRS-T) angle (p<0.001), SYNTAX score (p=0.039), serum high-sensitivity CRP levels (p=0.026), mean age (p<0.001), electrocardiographic left ventricular hypertrophy rate (LVH) (p=0.019), and hypertension rate (p=0.007) were higher, and the mean left ventricular ejection fraction (LVEF) (p<0.001) was lower in the POAF group. Multivariable logistic regression analyses demonstrated that lower LVEF (p=0.004), LVH (p=0.041), and higher age (p=0.008) and f(QRS-T) angle (p<0.001) were independently associated with POAF. High f(QRS-T) angle level is closely associated with the development of POAF. The f(QRS-T) angle can be a potential indicator of POAF.

Evaluation of thrombolytic treatment effect on frontal plane QRS-T angle in patients with acute pulmonary embolism : Anovel marker of successful thrombolysis.

Acute pulmonary embolism (APE) patients with hypotension and/or shock should be evaluated for thrombolytic therapy, and hemodynamics often improves after thrombolytic therapy. Frontal plane QRS‑T (f[QRS-T]) angle, which is between the directions QRS axis and Taxis, was described as anovel marker of ventricular repolarization heterogeneity. With right ventricular pressure overload, axis of heart may be affected and thrombolytic treatment may have an effect on this situation. This study aimed to investigate thrombolytic efficiency and effect on axis of heart by using f(QRS-T) angle. A total of 61APE patients treated with thrombolytics and 71APE patients treated without thrombolytics were included. Clinical findings and electrocardiogram (ECG) at diagnosis were collected. Second ECGs were included for patients with thrombolytics after 24 h, without thrombolytics after 72 h on average. No significant differences were observed with regard to gender, age, hypertension, diabetes and cardiovascular disease. In patients with thrombolytics, respiratory rate, heart rate and pulmonary artery systolic pressure were significantly higher; oxygen saturation (Sat O2) as well as systolic and diastolic pressure were significantly lower. f(QRS-T) was markedly higher in APE with right ventricular pressure overload and changed significantly after thrombolytic therapy. Right ventricular pressure overload in APE has an effect on f(QRS-T). In thrombolytic treatment, the change of f(QRS-T) angle may be amarker of successful thrombolysis.

Acute effect of cigarette smoking on frontal planar QRS-T angle in apparently healthy subjects with habitual smoking

Aim: It has been well recognized that smoking exerts various detrimental cardiovascular effects. Although the effect of chronic smoking on cardiac electrophysiology is well known, little is known about the effect of acute smoking on surface ECG. Previous reports suggested that frontal planar QRS-T angle (fpQRS-Ta), measured by surface ECG, may be associated with ventricular arrhythmias and cardiac death. Hence, we primarily aimed to assess the effect of acute smoking on fpQRS-Ta. Methods: A total of 92 apparently healthy subjects [44 female, 48 male, mean age 38.7(8.02) years] with smoking habit were enrolled in this prospective cohort study between May-July 2019. Demographic and clinical characteristics were recorded, and fpQRS-Ta together with some ECG parameters were noted before and 10 minutes after smoking for comparison. Spearman’s analysis was implemented to seek the probable correlation of the difference between pre- and post-smoking ECG parameters. Results: Ten minutes after smoking, median heart rate, QRS duration and fpQRS-Ta increased significantly (72.6 beats/min vs 81.5 beats/min, P<0.001; 84 ms vs 86 ms, P=0.012; 14.5° vs 25°, P<0.001; respectively), while PR and QTc duration did not significantly change (150.0 ms vs 150.0 ms, P=0.774; and, 423.5 ms vs 429.5 ms, P=0.372). In Spearman’s correlation analysis, the difference between pre- and post-smoking fpQRS-Ta significantly and negatively correlated with C-reactive protein (CRP) levels (r: -0.272, P=0.027). Conclusion: Acute smoking may widen fpQRS-Ta in healthy habitual smokers, and serum CRP negatively correlates with the degree of fpQRS-Ta widening. Our observation may further enlighten the pathophysiological mechanism of smoking in cardiac arrhythmias and sudden death.

Evaluation of frontal plane QRS-T angle in patients with slow coronary flow

Objectives. Frontal plane QRS-T angle is a novel marker of myocardial repolarization, and an increased frontal plane QRS-T angle is associated with adverse cardiac outcomes. Slow coronary flow may cause fatal cardiac arrhythmias by causing electrical abnormalities and altering ventricular repolarization. We aimed to evaluate the frontal plane QRS-T angle in patients with slow coronary flow. Design. A total of 60 consecutive patients with slow coronary flow and 60 consecutive patients with normal coronary flow were enrolled into the study. Laboratory and some electrocardiography parameters including frontal plane QRS-T angle were compared between the two groups. Results. We have found that the angle of frontal QRS-T was higher in the group with slow coronary flow (p < .001). In addition, there was a negative correlation between thrombolysis in myocardial infarction frame count and frontal QRS-T angle (r = −0.496, p < .001). Conclusions. In conclusion, increased frontal plane QRS-T angle might be an important indicator of slow coronary flow.