An evaluation of planarity of the spatial QRS loop by three dimensional vectorcardiography: Its emergence and loss

Ray, Dipanjan; Hazra, Sandipan; Goswami, Damodar Prasad; Macfarlane, Peter W.; Sengupta, Arnab

doi:10.1016/j.jelectrocard.2017.03.016

Cited by 13 publications

(8 citation statements)

References 31 publications

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“…Quasi-orthogonal: Repeated discussions (Cortez et al, 2014; Ray et al, 2017) suggested that instead of orthogonal algebraic reconstruction, vectorcardiographic loops might be obtained from standard ECG leads oriented in approximately perpendicular directions. Therefore, instead of the orthogonal XYZ leads obtained from the transformation, vector magnitude was calculated using the quasi-orthogonal leads II, V 2 , and V 5 , that is:…”

Section: Methodsmentioning

confidence: 99%

Detection of T Wave Peak for Serial Comparisons of JTp Interval

et al. 2019

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Electrocardiogram (ECG) studies of drug-induced prolongation of the interval between the J point and the peak of the T wave (JTp interval) distinguished QT prolonging drugs that predominantly block the delayed potassium rectifier current from those affecting multiple cardiac repolarisation ion channel currents. Since the peak of the T wave depends on ECG lead, a “global” T peak requires to combine ECG leads into one-dimensional signal in which the T wave peak can be measured. This study aimed at finding the optimum one-dimensional representation of 12-lead ECGs for the most stable JTp measurements. Seven different one-dimensional representations were investigated including the vector magnitude of the orthogonal XYZ transformation, root mean square of all 12 ECG leads, and the vector magnitude of the 3 dominant orthogonal leads derived by singular value decomposition. All representations were applied to the median waveforms of 660,657 separate 10-s 12-lead ECGs taken from repeated day-time Holter recordings in 523 healthy subjects aged 33.5 ± 8.4 years (254 women). The JTp measurements were compared with the QT intervals and with the intervals between the J point and the median point of the area under the T wave one-dimensional representation (JT50 intervals) by means of calculating the residuals of the subject-specific curvilinear regression models relating the measured interval to the hysteresis-corrected RR interval of the underlying heart rate. The residuals of the regression models (equal to the intra-subject standard deviations of individually heart rate corrected intervals) expressed intra-subject stability of interval measurements. For both the JTp intervals and the JT50 intervals, the curvilinear regression residuals of measurements derived from the orthogonal XYZ representation were marginally but statistically significantly lower compared to the other representations. Using the XYZ representation, the residuals of the QT/RR, JTp/RR and JT50/RR regressions were 5.6 ± 1.1 ms, 7.2 ± 2.2 ms, and 4.9 ± 1.2 ms, respectively (all statistically significantly different; p < 0.0001). The study concludes that the orthogonal XYZ ECG representation might be proposed for future investigations of JTp and JT50 intervals. If the ability of classifying QT prolonging drugs is further confirmed for the JT50 interval, it might be appropriate to replace the JTp interval since with JT50 it appears more stable.

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Section: Methodsmentioning

confidence: 99%

Detection of T Wave Peak for Serial Comparisons of JTp Interval

et al. 2019

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“… 18 The QRS non-planarity has previously been investigated mainly in relation to ischaemic heart disease and myocardial infarction. 3 18 19 Although about 60% of the patients of the study suffered from ischaemic heart disease, multivariable Cox regression analysis showed that the predictive value of QRS loop non-planarity was independent of heart disease aetiology. T wave loop abnormalities have also been repeatedly studied using different characteristics.…”

Section: Discussionmentioning

confidence: 92%

“…It has previously been reported that in physiological ECG recordings, the vectorcardiographic (VCG) loops of the QRS complex are essentially planarly, 3 that is, that the three-dimensional QRS dipole moves practically in a single plane the orientation of which depends on the position of the organ. Similar observations were also made for the VCG loop of the T wave.…”

Section: Introductionmentioning

confidence: 99%

QRS complex and T wave planarity for the efficacy prediction of automatic implantable defibrillators

Hnatkova,

Andršová,

Novotný

et al. 2023

Heart

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ObjectiveTo test the hypothesis that in recipients of primary prophylactic implantable cardioverter-defibrillators (ICDs), the non-planarity of ECG vector loops predicts (a) deaths despite ICD protection and (b) appropriate ICD shocks.MethodsDigital pre-implant ECGs were collected in 1948 ICD recipients: 21.4% females, median age 65 years, 61.5% ischaemic heart disease (IHD). QRS and T wave three-dimensional loops were constructed using singular value decomposition that allowed to measure the vector loop planarity. The non-planarity, that is, the twist of the three-dimensional loops out of a single plane, was related to all-cause mortality (n=294; 15.3% females; 68.7% IHD) and appropriate ICD shocks (n=162; 10.5% females; 87.7% IHD) during 5-year follow-up after device implantation. Using multivariable Cox regression, the predictive power of QRS and T wave non-planarity was compared with that of age, heart rate, left ventricular ejection fraction, QRS duration, spatial QRS-T angle, QTc interval and T-peak to T-end interval.ResultsQRS non-planarity was significantly (p<0.001) associated with follow-up deaths despite ICD protection with HR of 1.339 (95% CI 1.165 to 1.540) but was only univariably associated with appropriate ICD shocks. Non-planarity of the T wave loop was the only ECG-derived index significantly (p<0.001) associated with appropriate ICD shocks with multivariable Cox regression HR of 1.364 (1.180 to 1.576) but was not associated with follow-up mortality.ConclusionsThe analysed data suggest that QRS and T wave non-planarity might offer distinction between patients who are at greater risk of death despite ICD protection and those who are likely to use the defibrillator protection.

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“…ЭхоКГ То, что в норме пространственная петля QRS лежит в одной плоскости, объясняют тем, что компоненты электрической волны в сердце и в окружающей среде распространяются в трех взаимно перпендикулярных направлениях равномерным образом; скорость их распространения в любом направлении остается почти постоянной и однородной [4,6].…”

Section: таблица 2 значения индекса планарности у больных им в зависи...unclassified

“…Наши данные об уменьшении планарности петли QRS у больных ИМ совпадают как с давними [7,8,9], так и с более современными работами [5,6]. Данные литературы об изменениях планарности петли QRS при ИМ разных локализаций достаточно противоречивы.…”

Section: таблица 2 значения индекса планарности у больных им в зависи...unclassified

New possibilities of electrocardiography: evaluation of the vectorcardiographic QRS loop planarity in patients with myocardial infarction

Blinova

Sakhnova

Merkulova

et al. 2022

Evrazijskij kardiologičeskij žurnal

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The aim of the work is to evaluate the planarity of the QRS loop and its relationship with systolic dysfunction of the left ventricle in patients in the subacute period of myocardial infarction (MI).Materials and methods. The ECG of 265 patients with a diagnosis of acute myocardial infarction were analyzed. The control group consisted of 55 healthy individuals. The planarity index was calculated as the ratio of the area of the QRS loop projection onto the plane (the polar vector of the QRS loop) and the true area of the QRS loop in space using a synthesized vectorcardiogram.Results. In patients with MI, the planarity index was significantly lower than in healthy individuals: 0,87 [0,71; 0,94] and 0,96 [0,93; 0,97], respectively, p < 0,0001. Weak but significant correlations between the planarity index and the left ventricular ejection fraction (LVEF, r = 0,41, p < 0,001) and with the number of affected segments of the left ventricle according to echocardiography (r = −0,43, p < 0,001) were found. In patients with MI, the planarity index was lower in the presence of pulmonary edema in the acute period of MI (0,68 [0,54; 0,86]; without pulmonary edema 0,88 [0,76; 0,94], p < 0,001), and in the presence of a history of chronic heart failure (0,79 [0,61; 0,88]; without chronic heart failure 0,88 [0,75; 0,94], p = 0,007). In patients with MI of both anterior and inferior localization, the planarity index was significantly lower with LV EF < 50% compared with LV EF ≥ 50%. The planarity index was significantly lower in anterior MI than in inferior MI. Conclusion. In patients in the subacute period of MI, there is a decrease in the QRS loop planarity index, which correlates with the volume of myocardial damage, a decrease in LV EF, and the presence of acute and chronic heart failure. The QRS loop planarity index was significantly lower in anterior MI than in inferior MI.

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An evaluation of planarity of the spatial QRS loop by three dimensional vectorcardiography: Its emergence and loss

Cited by 13 publications

References 31 publications

Detection of T Wave Peak for Serial Comparisons of JTp Interval

Detection of T Wave Peak for Serial Comparisons of JTp Interval

QRS complex and T wave planarity for the efficacy prediction of automatic implantable defibrillators

New possibilities of electrocardiography: evaluation of the vectorcardiographic QRS loop planarity in patients with myocardial infarction

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