Value of the Qrs-T Angle in Predicting the Induction of Ventricular Tachyarrhythmias in Patients with Chagas Disease

Abstract

BackgroundThe QRS-T angle correlates with prognosis in patients with heart failure and coronary artery disease, reflected by an increase in mortality proportional to an increase in the difference between the axes of the QRS complex and T wave in the frontal plane. The value of this correlation in patients with Chagas heart disease is currently unknown. ObjectiveDetermine the correlation of the QRS-T angle and the risk of induction of ventricular tachycardia / ventricular fibrillation (VT / VF) during electrophysiological study (EPS) in patients with Chagas disease.MethodsCase-control study at a tertiary center. Patients without induction of VT / VF on EPS were used as controls. The QRS-T angle was categorized as normal (0-105º), borderline (105-135º) or abnormal (135-180º). Differences between groups for continuous variables were analyzed with the t test or Mann-Whitney test, and for categorical variables with Fisher's exact test. P values < 0.05 were considered significant.ResultsOf 116 patients undergoing EPS, 37.9% were excluded due to incomplete information / inactive records or due to the impossibility to correctly calculate the QRS-T angle (presence of left bundle branch block and atrial fibrillation). Of 72 patients included in the study, 31 induced VT / VF on EPS. Of these, the QRS-T angle was normal in 41.9%, borderline in 12.9% and abnormal in 45.2%. Among patients without induction of VT / VF on EPS, the QRS-T angle was normal in 63.4%, borderline in 14.6% and abnormal in 17.1% (p = 0.04). When compared with patients with normal QRS-T angle, those with abnormal angle had a fourfold higher risk of inducing ventricular tachycardia / ventricular fibrillation on EPS [odds ratio (OR) 4; confidence interval (CI) 1.298-12.325; p = 0.028]. After adjustment for other variables such as age, ejection fraction (EF) and QRS size, there was a trend for the abnormal QRS-T angle to identify patients with increased risk of inducing VT / VF during EPS (OR 3.95; CI 0.99-15.82; p = 0.052). The EF also emerged as a predictor of induction of VT / VF: for each point increase in EF, there was a 4% reduction in the rate of sustained ventricular arrhythmia on EPS.ConclusionsChanges in the QRS-T angle and decreases in EF were associated with an increased risk of induction of VT / VF on EPS.

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

“…In general, high QT dispersion values have been reported in patients with systemic HT and left ventricular hypertrophy (LVH) [16] . However, the pathophysiological mechanisms underlying repolarization abnormalities in patients with HT were partially explained.…”

“…The QRS-T angle has recently been shown to be a strong and independent predictor of cardiac mortality for various patient groups such as coronary artery disease [5] , heart failure [7] , type 2 diabetes mellitus [14] , elderly subjects [6] , postmenopausal women [15] , and Chagas disease [16] . Nonetheless, studies investigating the role of the QRS-T angle in HT are limited.…”

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

“…In 2000, however, the seminal report by Zabel et al, (2000) showed that the angle of the ventricular gradient, that is the 3-dimensional angle between the QRS and T wave orientations, is a potent predictor of mortality risk in survivors of acute myocardial infarction. Subsequently, the risk stratification strength of the QRS-T angle has been confirmed in a large number of studies including investigations of other ischaemic heart disease populations ( de Torbal et al, 2004 ; Malik et al, 2004 ), acute coronary syndrome ( Lown et al, 2012 ), heart failure ( Gotsman et al, 2013 ; Selvaraj et al, 2014 ; Sweda et al, 2020 ), hypertrophic ( Cortez et al, 2017a ; Cortez et al, 2017b ; Jensen et al, 2021 ) and dilated cardiomyopathy ( Li et al, 2016 ), diabetic patients ( Voulgari et al, 2010 ; Cardoso et al, 2013 ; May et al, 2017 ; May et al, 2018 ), renal patients on haemodialysis ( de Bie et al, 2013 ; Poulikakos et al, 2018 ); and many other populations and conditions ranging from systemic sclerosis ( Gialafos et al, 2012 ) and Chagas disease ( Zampa et al, 2014 ) to overall hospital ( Yamazaki et al, 2005 ) and general populations ( Kardys et al, 2003 ; Kors et al, 2003 ; Walsh et al, 2013 ). It has also recently been shown that QRS-T angle might be meaningfully combined with other ECG-based risk factors ( Hnatkova et al, 2022 ).…”