Figure 2.

QTVi and mortality. All-cause mortality across QTVi quartiles at baseline (A), arousal onset (C), and postarousal onset (E). Cumulative incident function curves comparing the competing risk of CV and non-CV mortality of dichotomized QTVi at baseline (B), arousal onset (D), and postarousal onset (F). QTVi values were dichotomized using the fourth quartile of the arousal onset QTVi distribution. P value shows log-rank test results. CV = cardiovascular; Q1-Q4 = quartiles of the QT variability index for Baseline QTVi, Arousal onset QTVi and Post Arousal onset QTVi; QTVi = QT variability index.