Low extracellular K+ increases intracellular Ca2+ oscillation and injury by activating the reverse mode Na+-Ca2+ exchanger and inhibiting the Na+, K+ ATPase in rat cardiomyocytes

These results suggest that increased calcium oscillations mediate the exacerbating reperfusion injury with low K+ on myocytes, and inhibition of Na+, K+ ATPase activity and increase of reverse-mode NCX activity contribute to these effects.