How can a cardiologist insert a catheter into a patients right femoral artery and then see the heart?

Cardiac cath: Cardiologists routinely access the arterial vessels at the top of either leg, the femoral artery, or from the arm, the radial artery. From here the catheter, or a guide wire is then fed through the arterial circulation into the heart. Just above the heart catheters are changed over a wire to access the left and right coronary arteries and the left ventricle.