The action potential is a sudden positive shift in the cardiomyocyte's cellular membrane potential, termed depolarization. Depolarization not only initiates contraction within the affected cardiomyocyte (Described in Cardiac Excitation-Contraction Coupling), but also initiates depolarization of adjacent cardiomyocytes.
Polar Coordinates The coordinate system which depicts the points from the pole to the certain distance at a particular angle is known as âpolar coordinatesâ. The positive horizontal axis in which that particular angle rotates is named as âpolar axisâ.
When we know a point in Polar Coordinates (r, Î¸), and we want it in Cartesian Coordinates (x,y) we solve a right triangle with a known long side and angle : Answer: the point (13, 22.6Â°) is almost exactly (12, 5) in Cartesian Coordinates. So, to convert from Polar Coordinates (r, Î¸) to Cartesian Coordinates (x,y) : 1  x = r Ã cos(Î¸).