ABC | Volume 110, Nº6, June 2018

Original Article Karaman et al Myocardial repolarization and VPC burden Arq Bras Cardiol. 2018; 110(6):534-541 Figure 1 – Scatter analysis of the correlation between the Tp-e interval and Tp-e/QTc ratio (in the leads V2 and V5) and the VPC burden. ms: millisecond; QTc: corrected QT; Tp-e: T wave peak-to-end interval; VPC: ventricular premature contraction. 15.0 10.0 5.0 .0 15.0 10.0 5.0 .0 15.0 10.0 5.0 .0 15.0 10.0 5.0 .0 80 90 100 110 120 130 80 90 100 110 120 70 60 VPC Burden (%/24 hours) VPC Burden (%/24 hours) VPC Burden (%/24 hours) VPC Burden (%/24 hours) p < 0.001 r = 0.476 p = 0.003 r = 0.296 p = 0.010 r = 0.256 p < 0.001 r = 0.395 .18 .20 .20 .22 .24 .26 .25 .28 .30 .30 .32 .35 .15 Tp-e in lead V2 (ms) Tp-e/QTc in lead V2 (ms) Tp-e/QTc in lead V5 (ms) Tp-e in lead V5 (ms) Group 2 Group 3 Group 1 Group 2 Group 3 Group 1 Group 2 Group 3 Group 1 Group 2 Group 3 Group 1 Table 3 – Relationship between ventricular premature contractions (VPC) burden and clinical and electrocardiographic parameters Variables VPC burden Pearson correlation coefficient p Beta regression coefficient p Age -0.026 0.797 - - Female sex 0.089 0.380 - - CAD 0.065 0.520 - - QTd 0.256 0.010 0.035 0.190 Lead V2 QT 0.362 < 0.001 0.067 0.749 QTc 0.243 0.015 0.148 0.382 Tp-e 0.476 < 0.001 -0.665 0.260 Tp-e/QT 0.171 0.088 -48.643 0.734 Tp-e/QTc 0.296 0.003 -366.464 0.059 Lead V5 QT 0.292 0.003 -0.151 0.449 QTc 0.173 0.085 -0.154 0,309 Tp-e 0.395 < 0.001 1.318 0.043 Tp-e/QT 0.185 0.066 -100.943 0.585 Tp-e/QTc 0.256 0.010 -405.136 0.024 QTc: corrected QT; QTd: QT dispersion; Tp-e: T wave peak-to-end interval; VPC: ventricular premature contraction. Pearson’s correlation and linear regression analyses. 538