No. As handsonanatomist mentions it has to do with blood flow to the myocardium(heart muscle itself). The heart muscle itself only receives oxygen during diastole(relaxation), but as heart rate increases the relative length of diastole shortens compared to systole(heart contraction). TLDR; your heart gets tired because it only gets oxygen while relaxed, and the relative amount of time spent relaxing is less.
Mine: is a possessive pronoun. Example :That is mine. My: is a possessive adjective. Example : That is my car. This is my iPodâ --- - This iPod is mine. This is my pen ------ This pen is mine. This is my car ------ This car is mine. Those are my paintings ------ those paintings are mine.
Strictly speaking there is some difference between the two words. A statue is a large sculpture of a person or an animal. It is usually made of stone or any other metal like bronze. On the other hand, a sculpture is a work of art, and it is produced by carving stone or wood or any other material for that matter.