High reliability rates of spatial pattern analysis by vectorcardiogram in assessing the severity of eccentric left ventricular hypertrophy

Ishizawa, Kazutoshi; Ishizawa, Kyoko; Motomura, Masakazu; Konishi, Tenji; Wakabayashi, Akira; Ishikawa, K.; Nohara, Yoshitsugu; Kawai, Chuichi; Koie, H

doi:10.1016/s0002-8703(76)80434-6

Cited by 37 publications

(24 citation statements)

References 19 publications

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“…9 An abnormal orientation of the T axis has long been known to provide a global measure of repolarisation abnormality, 22 and the spatial angle between the direction of the repolarisation and depolarisation waves (spatial QRS-T angle) has already been used to quantify ventricular repolarisation. 11,23,24 In this study, the spatial QRS-T angle was the only index found to be significantly higher in hypertensives who showed repeatedly high BP values as compared to those who had low BP levels. Previous studies have already reported a widened spatial QRS-T angle in patients with eccentric LVH, 11 and a decrease in the frontal or the horizontal QRS-T angle in patients following treatment of hypertension.…”

Section: Spatial Aspects Of Ventricular Repolarisation In Hypertensionmentioning

confidence: 47%

“…11,23,24 In this study, the spatial QRS-T angle was the only index found to be significantly higher in hypertensives who showed repeatedly high BP values as compared to those who had low BP levels. Previous studies have already reported a widened spatial QRS-T angle in patients with eccentric LVH, 11 and a decrease in the frontal or the horizontal QRS-T angle in patients following treatment of hypertension. 23 A widened QRS-T angle in patients with LVH was also reported when Grant's vectorial method was used.…”

Section: Spatial Aspects Of Ventricular Repolarisation In Hypertensionmentioning

confidence: 47%

“…Several studies have already attempted to quantify the spatial aspects of ventricular repolarisation. [8][9][10][11] The spatial aspects of the T wave complexity have been evaluated by the so-called principal component analysis, 8 while T axis has been reported to be a strong risk indicator of cardiac events in the elderly. 9 Furthermore, a recent study concluded that QT dispersion is largely determined by the T-loop morphology, as expressed by T-loop amplitude and width, 10 whereas an older one has reported a widened QRS-T angle in patients with eccentric left ventricular hypertrophy.…”

Section: Journal Of Human Hypertension (2001) 15 63-70mentioning

confidence: 99%

“…QRSxy, QRSxz, QRSyz, Txy, Txz, and Tyz were automatically calculated by our analysis system. According to previously published equations, 11 and by use of the Pythagorean theorem, the amplitude of the maximum spatial T vector (Spatial T amplitude) was calculated from the formula:…”

Section: Twelve-lead Vectorcardiogrammentioning

confidence: 99%

“…Furthermore, the angle (°) between the maximum spatial QRS and T vectors (Spatial QRS-T angle) was calculated from the formula: 11,15 cos °ϭ (QRSxTx + QRSyTy + QRSzTz)/͉QRS͉ ͉T͉…”

Section: Twelve-lead Vectorcardiogrammentioning

confidence: 99%

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The spatial QRS-T angle as a marker of ventricular repolarisation in hypertension

et al. 2000

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Section: Spatial Aspects Of Ventricular Repolarisation In Hypertensionmentioning

confidence: 47%

Section: Spatial Aspects Of Ventricular Repolarisation In Hypertensionmentioning

confidence: 47%

Section: Journal Of Human Hypertension (2001) 15 63-70mentioning

confidence: 99%

Section: Twelve-lead Vectorcardiogrammentioning

confidence: 99%

“…Furthermore, the angle (°) between the maximum spatial QRS and T vectors (Spatial QRS-T angle) was calculated from the formula: 11,15 cos °ϭ (QRSxTx + QRSyTy + QRSzTz)/͉QRS͉ ͉T͉…”

Section: Twelve-lead Vectorcardiogrammentioning

confidence: 99%

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The spatial QRS-T angle as a marker of ventricular repolarisation in hypertension

et al. 2000

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

Dilaveris

Gialafos

Poloniecki

et al. 2000

Clinical Cardiology

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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.

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Ibutilide‐induced alterations in electrocardiographic and spatial vectorcardiographic descriptors of ventricular repolarization

Dilaveris

Theoharis

Giaouris

et al. 2004

Clinical Cardiology

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SummaryBackground: Ibutilide is used for the pharmacologic cardioversion of atrial fibrillation (AF) or flutter (AFl). Ibutilideinduced QT interval prolongation has been demonstrated previously. However, its effects on vectorcardiographic (VCG) descriptors of ventricular repolarization (VR) have not been studied so far.Hypothesis: To evaluate the effects of ibutilide on electrocardiographic (ECG) and VCG descriptors of VR, one or two repeated 10-min infusions of 1 mg of ibutilide were given in 50 consecutively recruited patients (36 women, mean age 69.4 ± 9.3 years) with AF or AFl of recent onset.Methods: The maximum and the minimum QT intervals, QT dispersion, the rate-corrected QT maximum, and the spatial VCG descriptors, spatial T amplitude, and spatial QRS-T angle were calculated before (baseline ECG) and 30 min after the start of ibutilide infusion (postinfusion ECG).Results: After ibutilide infusion, 40 (80%) patients were cardioverted to sinus rhythm (Group 1), while in the remaining 10 (Group 2) AF or AFl persisted. In both study groups, temporal measures of VR were significantly increased from baseline to the postinfusion ECG. In Group 1, spatial T amplitude and spatial QRS-T angle did not differ between those two ECGs, while in Group 2 spatial T amplitude was significantly increased (p = 0.005) and spatial QRS-T angle was significantly decreased (p = 0.002) post infusion compared with baseline ECG.Conclusions: While temporal measures of VR are significantly affected in all patients who receive ibutilide infusion for AF or AFl cardioversion, spatial VCG descriptors of VR are

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High reliability rates of spatial pattern analysis by vectorcardiogram in assessing the severity of eccentric left ventricular hypertrophy

Cited by 37 publications

References 19 publications

The spatial QRS-T angle as a marker of ventricular repolarisation in hypertension

The spatial QRS-T angle as a marker of ventricular repolarisation in hypertension

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

Ibutilide‐induced alterations in electrocardiographic and spatial vectorcardiographic descriptors of ventricular repolarization

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