Wavelet Transform Analysis of High Resolution Electrocardiograms in Patients with Arrhythmogenic Right Ventricular Dysplasia.

Samir Fareh, Jean-Philippe Couderc, Gilbert Kirkorian, Philippe Chevalier, Jocelyne Fayn, Paul Rubel, Paul Touboul, Hopital Cardiologique et INSERM U121, Lyon, France.

Late potentials (LPs) are often present in patients (Pts) with arrythmogenic right ventricular dysplasia (ARVD) resulting from fibro-adiposis infiltration of the free wall of the right ventricule. The purpose of this study was to analyze the relevance of the wavelet transform (WT) of the high-resolution electrocardiogram (HRECG) versus the time-domain analysis.

HRECGs were recorded in 16 Pts with ARVD and in 51 control normal subjects. Based on the upper 96% limits of the time-domain parameters of control subjects, Pts with at least 2/3 abnormal parameters (QRS>105 ms, LAS40>39 ms, RMS40<23.9) were considered as having LPs. Morlet WT of the three unfiltered X,Y and Z leads were performed. We analyzed the QRS-ST complex of the HRECGs between 47HZ and 273Hz. ARVD Pts were optimally discriminated from normals (p<0.001) when considering the activity in the 100-167 Hz and 105-127 ms after the QRS onset time-frequency area. The criteria for positivity was based on the detection of high-frequency energy in the 100-167 Hz x 105-127 ms time-frequency area in at least one of the three leads. The detection threshold was the upper 96% limit of the control Pts. Sensitivity and specificity were respectively 81% and 96% for the time-domain analysis and 94% and 90% for the WT method.

In conclusion, WT of the HRECG identifies high-frequency components localized in the terminal portion of the QRS complex in Pts with ARVD. The quantification of this activity optimizes the diagnostic value of the HRECG.

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