What is the fine-grained topic of the following text: Calcium salts such as calcium gluconate and calcium chloride work to improve cellular contractility by increasing the concentration gradient of calcium in the extracellular fluid, driving calcium intracellularly via unblocked channels.5 However, remember that calcium (as with many of these treatment options) works upstream of the calcium channel, and the effect of calcium salts has shown to be variable. Only return the topic.
The effect of calcium salts on cellular contractility