Body Surface Mapping of Ventricular Repolarization Heterogeneity: An Ex-vivo Multiparameter Study

FIGURE 1. A representative single-lead QRST sequence from a tank potential recorded from an experiment from Dof & Pin Group before (Baseline, blue trace) and after induction of repolarization gradients through injection of dofetilide (Dof, green trace) and simultaneous perfusion with dofetilide and pinacidil (Dof + Pin, red trace).

FIGURE 2. Time evolution of signal features and their variations with respect to baseline conditions for experiments from Pin Group, computed before and during progressive injection with pinacidil. (A) Invasive epicardial metrics of heterogeneity of repolarization and changes from baseline computed as global differences in RTs between Pin- and not-Pin sites (RTGGLOBAL and ΔRTGGLOBAL, left), global differences in RTs between LV and RV (RTG(LV/RV)GLOBAL and ΔRTG(LV/RV)GLOBAL, middle), and local RT gradients between neighboring epicardial sock nodes (RTGLOCAL and ΔRTGLOCAL, right). (B) BSPM indices and changes from baseline of T-wave duration (TPEAK-TEND and ΔTPEAK-TEND, left) and corrected QT interval (QTC and ΔQTC, right). (C) BSPM indices and changes from baseline of temporal variability of T-wave duration [SD(TPEAK-TEND) and ΔSD(TPEAK-TEND), left] and QTC spatial dispersion (QTD and ΔQTD, right). (D) BSPM indices and changes from baseline of T-wave symmetry (Asy and ΔAsy, left) and shape (dLV/RV and ΔdLV/RV, right). (E) BSPM indices and changes from baseline of T-wave complexity (CR and ΔCR, left, and NMSE and ΔNMSE, right). a.u., arbitrary units.

FIGURE 3. BA plots of the differences zD between BSPM markers of T-wave and invasive RT dispersion measures vs. their mean zM for the assessment of the agreement between the two approaches for experiments from Pin Group before and during progressive injection with pinacidil. The mean difference between methods (horizontal continuous black line) and upper and lower 95% LoA (dashed magenta and green lines, respectively) are also displayed. (A) BSPM indices and T-wave duration (TPEAK-TEND, left) and corrected QT interval (QTC, right). (B) BSPM indices of temporal variability of T-wave duration [SD(TPEAK-TEND), left] and QTC spatial dispersion (QTD, right). (C) BSPM indices of T-wave symmetry (Asy, left) and shape (dLV/RV, right). (D) BSPM indices of T-wave complexity (CR, left, and NMSE, right). a.u., arbitrary units.

FIGURE 4. Time evolution of signal features and their variations with respect to baseline conditions for experiments from Dof & Pin Group, computed before and during progressive injection with dofetilide and pinacidil. (A) Invasive epicardial metrics of heterogeneity of repolarization and changes from baseline computed as global differences in RTs between Pin- and not-Pin sites (RTGGLOBAL and ΔRTGGLOBAL, left), global differences in RTs between LV and RV (RTG(LV/RV)GLOBAL and ΔRTG(LV/RV)GLOBAL, middle), and local RT gradients between neighboring epicardial sock nodes (RTGLOCAL and ΔRTGLOCAL, right). (B) BSPM indices and changes from baseline of T-wave duration (TPEAK-TEND and ΔTPEAK-TEND, left) and corrected QT interval (QTC and ΔQTC, right). (C) BSPM indices and changes from baseline of temporal variability of T-wave duration [SD(TPEAK-TEND) and ΔSD(TPEAK-TEND), left] and QTC spatial dispersion (QTD and ΔQTD, right). (D) BSPM indices and changes from baseline of T-wave symmetry (Asy and ΔAsy, left) and shape (dLV/RV and ΔdLV/RV, right). (E) BSPM indices and changes from baseline of T-wave complexity (CR and ΔCR, left, and NMSE and ΔNMSE, right). a.u., arbitrary units.

FIGURE 5. BA plots of the differences zD between BSPM markers of T-wave and invasive RT dispersion measures vs. their mean zM for the assessment of the agreement between the two approaches for experiments from Dof & Pin Group before and during progressive injection with dofetilide and pinacidil. The mean difference between methods (horizontal continuous black line) and upper and lower 95% LoA (dashed magenta and green lines, respectively) are also displayed. (A) BSPM indices and T-wave duration (TPEAK-TEND, left) and corrected QT interval (QTC, right). (B) BSPM indices of temporal variability of T-wave duration [SD(TPEAK-TEND), left] and QTC spatial dispersion (QTD, right). (C) BSPM indices of T-wave symmetry (Asy, left) and shape (dLV/RV, right). (D) BSPM indices of T-wave complexity (CR, left, and NMSE, right). a.u., arbitrary units.