Session P92.10

Digital Phono- and Electrocardiography: Predicting Echocardiographic Parameters for Telemedicine Screening

S Khoor*, I Kovacs, K Fugedi, G Horvath,
E Domijan, M Domijan

Szent Istvan Hospital
Budapest, Hungary

Our study was performed to assess the clinical value of digital phono- and electrocardiography (dPECG) in telemedicine application for screening. The most important standard echocardiographic parameters (left ventricular (LV), both atrial dimensions; ejection fraction (EF), aortic Vmax, the grade of mitral and tricuspid regurgitation (MR and TR: semi-quantitative grade I, II, and III, the peak regurgitant velocity, the velocity-time integral (VTI of MR and TR; the left ventricular mass index (LVMI) were estimated from the dPECG data. The study population consists of 790 patients selected from our large database containing all of the relevant clinical parameters: the digital, 12-lead ECG, the 30-second dPCG registration and the complete echocardiographic video. 395-395 patients are in the training and the test groups. The input values of the first model were the automated measured dECG parameters (amplitudes and duration of P-, or F/f-wave, R-, T-waves ). After the factor analysis, the data reduction was performed, and the multivariate discriminant model (MDSC) was used for the prediction of echo parameters. A logistic regression analysis was used for some categorical ECG parameters (signs of strain, q-wave in aVR, e.t.c.). The dPCG registrations were localized in the standard 6 places, but only the apex localization was used. The signal analysis of the phonocardiogram consists of the following steps: 1. discrete FFT analysis; 2. automated first and second heart sound (S1 and S2) detection (segmentation of one cycle); 3. filtering and averaging; 4. parameter calculation for the MDSC model (input: dPCG time-frequency mean values of 4-4 during S1 and S2, 8-8 during systole and diastole, the frequency values were 23.4, 39.1, 54.7, 70.3, 85.9, 101.6, 117.2, 132.8, 148.4, 164.1, 179.7, 195.3, 210.9, 226.6, 242.2, 257.8, 273.4, 289.1, 304.7, 320.3, and 335.9 Hz. The factor and discriminant analysis were also performed. The best result of estimation with dECG: LVMI: number of input parameters: 8, Wilks' lambda: 0.245, chi-square: 102.5 sign.<0.001 and the classification results for the three output groups 83.9%, 82.1%, 80.0%; MR: 6, 0.289, 78.7, .<0.001, 76.2.0%, 71.3%, 80.50%; and for dPCG: Vmax: 5, 0.193, 296.9, 0.001, 96.9%, 100.0%, 88.9%; EF: 4, 0.822, 35.5, <0.001, 87.5%, 55.3%, 48.9%. These results are used for the optimizing the patients’ selection to echocardiographic screening study.

(Abstract Control Number: 329)