Electrocardiographic findings in patients with chronic kidney disease based principal components analysis

The purpose of this study was to investigate findings in electrocardiographic (ECG) parameters in patients with chronic kidney disease (CKD) based on Principal Component (PC) Analysis. This study was designed as a cross-sectional study of consisted of twenty-five men subjects 36 to 80 years with a diagnosis of stage 5 of CKD, selected at random from Nephrology Unit Hospital. All subjects were instructed to lie in the supine position for 3 min at rest while breathing normally with a ECG working at a sampling rate of 1200 Hz was used to record ECG parameters to obtain the classical parameters iPR, sPR, iQRS, sST, iRR and QTc and, subsequently, re-sampling procedure to bootstrapping based on 1000 samples. The PCs involve the calculation of the eigenvalue decomposition of the ECG parameters covariance matrix and use of the biplot graph, in order to understand the importance of each variable. CKD was associated with iRR (PC1: 0.998 and PC2: -0.040) ECG parameter showed greater contributions to PC1 and the QTc ECG parameter (PC1: -0.005 and PC2: 0.813) showed bigger contributions to PC2. In conclusion, the ECG findings in patients with CKD are particularly caused by reducing the RR interval and prolonged QT interval are particularly caused by an increase in the tone of the sympathetic nervous system.