Changes of the t‐wave amplitude and angle: An early marker of altered ventricular repolarization in hypertension

Abstract

summaryBackground: The heterogeneity of ventricular repolarization is an important promhythmic factor. QT dispersion has been proposed to reflect the inhomogeneity of ventricular repolarization, but a poor reproducibility limits its clinical applicability. Reliable noninvasive methods to quantlfy abnormalities in ventricular repolarization are still lacking. The T-loop morphology analysis is a novel method aimed at quantifying ventricular repolarization.Hypothesis: To test the ability of the T-loop morphology analysis to discriminate between hypertensive patients and healthy subjects, 105 hypertensive patients (mean age 63.6 +-12.3 years) and 110 healthy controls (mean age 49.7 f 14.3 years) were evaluated. Methods:The maximum QT interval (QT maximum), the minimum QT interval (QT minimum), and their difference (QT dispersion) were calculated from a digitally recorded 12-lead electrocardiogram (ECG) in both study groups. X, Y, and Z leads were reconstructed from the 12-lead ECG, and the amplitude of the maximum T vector (T amplitude) and the angle between the maximum T vector and X axis (Tangle) were calculated from the projection of the T loop in the frontal plane.

The association of spatial T wave axis deviation with incident coronary events. The ARIC cohort

“…Our study confirms the results of other studies [18,19] in finding a strong association between spatial T wave axis and hypertension status. The explanation is likely related to the presence of an increased left ventricular wall in the context of the left ventricular hypertrophy.…”

“…Heart rate influences have been reported on the frontal plane T wave angle [18] and on the spatial ST-T vector [38]. The physiologic explanation of the dependency of an angular measure on heart rate is not clear.…”

“…Clinical studies have shown that the T wave axis reflects changes associated with autonomic adaptive or maladaptive influences [17], systemic hypertension [18,19], coronary occlusion [20], and microalbuminuria in individuals without diabetes mellitus [21]. Moreover, it has recently been shown that spatial T wave axis deviation has good measurement properties and is repeatable [22], a finding that supports its use in clinical and epidemiological research.…”

QTc dispersion and Cornell duration product can predict 10‐year outcomes in hypertensive patients with left ventricular hypertrophy

“…Dilaveris et al. examined QTc dispersion in hypertensive patients . This study defined LVH by ECG criteria.…”

Tv1 Taller Than Tv6 as the Only Electrocardiographic Indication of Cardiac Disease

“…Although the QRS changes often precede the Twave changes, such is not always the case, and anterior rotation of the T-wave vector before significant QRS changes are seen accounts for the isolated TV 1 -taller-than-TV 6 pattern in hypertensive patients. Dilaveris et al recently described a decrease in T-wave amplitude in the frontal plane as an early marker of altered ventricular repolarization that may occur before QRS voltage changes in patients with systemic hypertension (2). They did not comment on horizontal-plane changes, which account for the TV 1 -taller-than-TV 6 pattern.…”