Prognostic Significance of Frontal QRS-T Angle in Patients with Idiopathic Dilated Cardiomyopathy

Circulating biomarker- and magnetic resonance-based nomogram predicting long-term outcomes in dilated cardiomyopathy

BACKGROUND

Dilated cardiomyopathy (DCM) has a high mortality rate and is the most common indication for heart transplantation. Our study sought to develop a multiparametric nomogram to assess individualized all-cause mortality or heart transplantation (ACM/HTx) risk in DCM patients.

METHODS

The present study is a retrospective cohort study. The demographic, clinical, blood test, and cardiac magnetic resonance imaging (CMRI) data of DCM patients in the tertiary center (Fuwai Hospital) were collected. The primary endpoint was ACM/HTx. The least absolute shrinkage and selection operator (LASSO) Cox regression model was applied for variable selection. Multivariable Cox regression was used to develop a nomogram. The concordance index (C-index), area under the receiver operating characteristic curve (AUC), calibration curve, and decision curve analysis (DCA) were used to evaluate the performance of the nomogram.

RESULTS

A total of 218 patients were included in the present study. They were randomly divided into a training cohort and a validation cohort. The nomogram was established based on eight variables, including mid-wall late gadolinium enhancement, systolic blood pressure, diastolic blood pressure, left ventricular ejection fraction, left ventricular end-diastolic diameter, left ventricular end-diastolic volume index, free triiodothyronine, and N-terminal pro-B type natriuretic peptide. The AUCs regarding 1-year, 3-year, and 5-year ACM/HTx events were 0.859, 0.831, and 0.840 in the training cohort and 0.770, 0.789, and 0.819 in the validation cohort, respectively. The calibration curve and DCA showed good accuracy and clinical utility of the nomogram.

CONCLUSIONS

We established and validated a circulating biomarker- and CMRI-based nomogram that could provide a personalized prediction of ACM/HTx for DCM patients, which might help risk stratification and decision-making in clinical practice.

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.

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.

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.

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.

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.

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.

Predictive value of electrocardiographic markers in children with dilated cardiomyopathy

Dilated cardiomyopathy (DCM) refers to a heterogeneous group of cardiomyopathies characterized by ventricular dilatation and myocardial systolic dysfunction, which can lead to serious consequences such as malign arrhythmia, sudden death, heart failure, and thromboembolism. With its economical, non-invasive, simple and reproducible advantages, electrocardiogram (ECG) has become an important indicator for assessing the prognosis of cardiovascular diseases. In recent years, more and more studies of electrocardiography on DCM have been carried out, but there is still a lack of a comprehensive summary of its prognostic value. This article reviews the prognostic value of electrocardiographic markers in children with DCM.

Predictive value of frontal QRS-T angle after cardiac resynchronization therapy

OBJECTIVE

It is practical and useful to detect patients who benefit from cardiac resynchronization therapy (CRT) by electrocardiographic (ECG) methods. In this study, the predictive role of the frontal QRS-T angle and other ECG parameters was evaluated in CRT responder patients.

METHOD

Seventy-seven consecutive patients with left ventricular ejection fraction (LVEF) ≤ 35%, New York Heart Association (NYHA) classes II-III, ambulatory class IV and normal sinus rhythm, who had complete left bundle branch block and were treated with CRT were included in this study. Patients were classified as "CRT responders" and "CRT non responders" according to their LVEF improvement. The frontal QRS-T angle was calculated as the absolute value of the difference between the QRS and T wave axes [frontal QRS-T angle = (QRS axis-T axis)].

RESULTS

The mean age of the patients was 64.5 ± 9.1 years, and the average follow-up was 28 (12-47) months. The post-implantation LVEF was higher in the patients CRT responders group (p < 0.001). Post-implantation frontal QRS-T angle (p = 0.003), QRS duration (p = 0.008) and cQT interval (p = 0.012) values were much shorter in the CRT responder group. Multivariable regression analyses showed that the frontal QRS-T angle and age were independent risk factors for CRT response (p = 0.009). The results of the receiver operating characteristic curve analyses (ROC) showed that the predictive optimal cut-off value of CRT response for the frontal QRS-T angle was <135 degrees (AUC: 0.69, 95% CI 0.575-0.814, p = 0.004).

CONCLUSION

The narrowed frontal QRS-T angle (<135 degrees), QRS duration and cQT interval were associated with CRT response in heart failure patients. The frontal QRS-T angle can be an independent predictor of CRT response.

Associations of frontal QRS-T angle with left ventricular volume and function derived from ECG-gated SPECT in patients with advanced chronic kidney disease

BACKGROUND

The frontal QRS-T angle is one of markers of ventricular repolarization. We investigated whether or not the frontal QRS-T angle could predict left ventricular (LV) volume and function derived from ECG-gated SPECT in patients with advanced chronic kidney disease (CKD).

METHODS

Two hundred and twelve patients with advanced CKD defined as estimated glomerular filtration rate of < 45 ml min-1/1.73 m2 were enrolled. Wide QRS-T angle was defined as its angle of > 90°, and was considered abnormal. Enlarged LV end-diastolic volume (LVEDV) was defined as LVEDV index of > 76 ml m-2 in men and > 57 ml m-2 in women. Reduced LV ejection fraction (LVEF) was defined as LVEF of < 40%.

RESULTS

Fifty-one patients (24%) had wide QRS-T angle, and 161 patients (76%) had normal QRS-T angle. Patients with wide QRS-T angle had larger SSS [9 (5-16) vs 4 (1-9), p < 0.001], larger LVEDV index (69 ± 29 vs 50 ± 18 ml m-2, p < 0.001) and lower LVEF (47 ± 13 vs 59 ± 12%, p < 0.001) than those with normal QRS-T angle. Multivariate analysis showed that wide QRS-T angle (odds ratio 5.93; 95% CI 2.55-14.33; p < 0.001) was significantly associated with enlarged LVEDV, whereas SSS severity was not. Severely abnormal SSS (odds ratio 3.80; 95% CI 1.16-14.05; p < 0.03) and wide QRS-T angle (odds ratio 5.67; 95% CI 2.10-16.22; p < 0.001) were significantly associated with reduced LVEF.

CONCLUSIONS

Our results suggest that wide QRS-T angle is associated with LV remodeling such as enlarged LVEDV or reduced LVEF in patients with advanced CKD.

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

WHAT IS KNOWN AND OBJECTIVE

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.

METHODS

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.

RESULTS AND DISCUSSION

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).

WHAT IS NEW AND CONCLUSION

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.

[Diagnostic and prognostic significance of QRS-T angle]

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

Electrocardiographic Predictors of Morbidity and Mortality in Patients With Acute Myocarditis: The Importance of QRS-T Angle

BACKGROUND

Acute myocarditis carries a variable prognosis. We evaluated the morbidity and mortality rates in patients with acute myocarditis and admission electrocardiographic predictors of outcome.

METHODS AND RESULTS

Patients admitted to a tertiary hospital with a clinical diagnosis of acute myocarditis were evaluated; 193 patients were included. Median follow-up was 5.7 years, 82% were male, and overal median age was 30 years (range 21-39). The most common clinical presentations were chest pain (77%) and fever (53%). The 30-day survival rate was 98.9%. Overall survival during follow-up was 94.3%. The most common abnormalities observed on electrocardiography were T-wave changes (36%) and ST-segment changes (32%). Less frequent changes included abnormal T-wave axis (>105° or < -15°; 16%), abnormal QRS axis (12%), QTc >460 ms (11%), and QRS interval ≥120 ms (5%). Wide QRS-T angle (≥100°) was demonstrated in 13% of the patients and was associated with an increased mortality rate compared with patients with a narrow QRS-T angle (20% vs 4%; P = .007). The rate of heart failure among patients with a wide QRS-T angle was significantly higher (36% vs 10%; P = .001). Cox regression analysis demonstrated that a wide QRS-T angle (≥100°) was a significant independent predictor of heart failure (hazard ratio [HR] 3.20, 95% confidence interval [CI] 1.35-7.59; P < .01) and of the combined end point of death or heart failure (HR 2.56, 95% CI 1.14-5.75; P < .05).

CONCLUSIONS

QRS-T angle is a predictor of increased morbidity and mortality in acute myocarditis.