title: Can P wave wavelet analysis predict atrial fibrillation after coronary artery bypass grafting?
abstract: The purpose of this study was the evaluation of Morlet wavelet analysis of the P wave as a means of predicting the development of atrial fibrillation (AF) in patients who undergo coronary artery bypass grafting (CABG). The P wave was analyzed using the Morlet wavelet in 50 patients who underwent successful CABG. Group A consisted of 17 patients, 12 men and 5 women, of mean age 66.9 +/- 5.9 years, who developed AF postoperatively. Group B consisted of 33 patients, 29 men and 4 women, mean age 62.4 +/- 7.8 years, who remained arrhythmid-free. Using custom-designed software, P wave duration and wavelet parameters expressing the mean and maximum energy of the P wave were calculated from 3-channel digital recordings derived from orthogonal ECG leads (X, Y, and Z), and the vector magnitude (VM) was determined in each of 3 frequency bands (200-160 Hz, 150-100 Hz and 90-50 Hz). Univariate logistic-regression analysis identified a history of hypertension, the mean and maximum energies in all frequency bands along the Z axis, the mean and maximum energies (expressed by the VM) in the 200-160 Hz frequency band, and the mean energy in the 150-100 Hz frequency band along the Y axis as predictors for post-CABG AF. Multivariate analysis identified hypertension, ejection fraction, and the maximum energies in the 90-50 Hz frequency band along the Z and composite-vector axes as independent predictors. This multivariate model had a sensitivity of 91% and a specificity of 65%. We conclude that the Morlet wavelet analysis of the P wave is a very sensitive method of identifying patients who are likely to develop AF after CABG. The occurrence of post-CABG AF can be explained by a different activation pattern along the Z axis.
authors.affiliation: First Cardiology Division, Aristotle University of Thessaloniki, Greece. vvassil@med.auth.gr
authors.forename: Vassilios
authors.initials: V
authors.lastname: Vassilikos
authors.forename: George
authors.initials: G
authors.lastname: Dakos
authors.forename: Ioanna
authors.initials: I
authors.lastname: Chouvarda
authors.forename: Labros
authors.initials: L
authors.lastname: Karagounis
authors.forename: Haralambos
authors.initials: H
authors.lastname: Karvounis
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Maglaveras
authors.forename: Sotirios
authors.initials: S
authors.lastname: Mochlas
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Spanos
authors.forename: George
authors.initials: G
authors.lastname: Louridas
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000209:etiology; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted