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

Abstract

Objective: The present study was undertaken to investigate the prognostic value of the frontal planar QRS-T angle in patients without angiographically apparent coronary atherosclerosis. Subjects and Methods: Three hundred and seven patients with normal coronary arteries on coronary angiography were included. The absolute difference between the frontal QRS- and T-wave axes was defined as the frontal planar QRS-T angle, and patients were divided into 3 subgroups based on the frontal planar QRS-T angle (<45, 45-90, and >90°). Demographic, clinical, laboratory, and angiographic data were compared between groups. Based on the regression analysis results, patients were recategorized into 4 groups according to their luminal calibers of left main coronary artery (LMCA) and history of hypertension (HT) (nonhypertensive LMCA ≤4.13 mm, nonhypertensive LMCA >4.13 mm, hypertensive LMCA ≤4.13 mm, and hypertensive LMCA >4.13 mm). Results: The median value of the frontal planar QRS-T angle of all participants was 38°. Subjects with the widest frontal planar QRS-T angle were older (p = 0.027), were hypertensive (p = 0.001), and had higher corrected QT values (p = 0.001). Patients with the widest frontal planar QRS-T angle had larger LMCA and left anterior descending coronary artery diameters compared to subjects with a normal and borderline frontal QRS-T angle (p = 0.004 and p = 0.028, respectively). Corrected QT, HT, and LMCA diameter were found as independent predictors of the frontal planar QRS-T angle. Subjects with HT and a larger luminal caliber of LMCA had the widest frontal planar QRS-T angle. Conclusion: Patients with a history of HT and a larger luminal caliber of LMCA had the widest frontal planar QRS-T angle. Since HT-induced electrophysiological changes are still not well established and we observed that changes in the luminal caliber of coronary arteries are associated with an abnormal frontal QRS-T angle, the frontal QRS-T angle could serve as a marker of ventricular repolarization heterogeneity in hypertensive patients in addition to keeping track of arrhythmic events, even before overt disease.

The role of baseline and post‐procedural frontal plane QRS‐T angles for cardiac risk assessment in patients with acute STEMI

“…Normally, the directions of the myocardial depolarization axis and repolarization axis is in the similar orientation. Therefore, f(QRS-T) angle often tend to be a narrow angle (<45°) (Gungor et al, 2017;Raposeiras-Roubin et al, 2014;Tan et al, 2017). A wider f(QRS-T) angle is associated with discordance between ventricular depolarization phase and repolarization phase and it was found to be associated with poor outcomes in different populations (Pavri et al, 2008;Raposeiras-Roubin et al, 2014).…”

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

“…Although there is no certain reference range for a normal fpQRS-T angle, some studies opt to regard a fpQRS-T angle <45 degrees as normal, between 45-90 degrees as borderline and >90 degrees as abnormal [11,16,37]. In their study, Chua et al [16] pointed out to a cut-off value >90 degrees for a fpQRS-T angle to predict sudden cardiac death independently of the left ventricular ejection fraction in a large cohort of patients possessing cardiovascular disease risk factors.…”

Diagnostic and prognostic significance of QRS-T angle

“…Независимые предикторы увеличения фронтального угла QRS-T у лиц с интактными коронарными артериями -корригированный интервал QT, АГ и увеличение диаметра ствола левой коронарной артерии (M. Gungor и соавт., 2017) [39], а у лиц с ожирением -ИМТ и масса миокарда ЛЖ (S. Kurisu и соавт., 2018) [40].…”