FIG. 6.

Effects of the ROS-mediated increase in intracellular Na on Ca transients and contractility. Increased intracellular Na disables the Ca extruding capacity of the Na^/Ca exchanger (NCX) and favors ‘reverse mode’ of the NCX, which increases intracellular and diastolic Ca and contributes to diastolic dysfunction. Increased SR Ca leak leads to reduced SR Ca load and reduced contractility, and also contributes to increased intracellular Ca. (To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/ars.)