Session P72.2

Comparison of Different Methods for the Derivation of the Vectorcardiogram from the ECG and Morphological Descriptors

JA Belloch, MS Guillem, AM Climent, D Husser,
J Millet*, A Bollmann

Universidad Politécnica de Valencia
Valencia, Spain

Several methods have been proposed for both the derivation of the vectorcardiogram from the 12-lead ECG and the quantification of the morphology of vectorcardiograms. The aim of this study was to compare commonly used QRS/T morphological descriptors obtained with different transforms. Selected methods and measurements have been implemented in order to determinate whether those methods are comparable or if they offer disparate results. A database consisting of 10-second 12-lead ECG recordings of 180 patients with cardiomyopathy and/or bundle branch block was used. Vectorcardiograms were reconstructed by applying Singular Value Decomposition and Dower’s inverse transform. For each individual QRS complex and T wave their averaged QRS complexes and T waves several morphological parameters were calculated: planes of best fit, deviation of individual waves from the average, morphology dispersion ratio, complexity ratio, wave residuum and normalized loop area. Paired t tests and correlations were calculated among parameters derived from SVD-derived vectorcardiograms and Dower-derived vectorcardiograms. The same procedure was applied among selected parameters derived with the same derivation method. None of the QRS measurements were similar when comparing SVD vs. Dower derivations. Correlations between parameters on the T wave showed higher correlations (deviation of T waves from the averaged T wave: rho= 0.8 p<0.01). Low correlation values were found among any of the morphological parameters under evaluation. We conclude that vectorcardiographic parameters obtained from Dower’s inverse transform and SVD are disparate. Morphological descriptors implemented over the vectorcardiograms also offer different results.

(Abstract Control Number: 91)