Time domain indexes derived from HP and QT series in the BBoff-BBon protocol.

μHP = HP mean; σ2HP = HP variance; μQT = QT mean; σ2QT = QT variance; BBoff = off beta-blocker therapy; BBon = on beta-blocker therapy; ASYMP = asymptomatic group; SYMP = symptomatic group. Results are reported as mean ± standard deviation. The symbol * indicates p<0.05 within the same group (i.e. ASYMP or SYMP) versus BBoff. The symbol # indicates p<0.05 within the same therapy (i.e. BBoff or BBon) versus ASYMP subjects.