By taking a cross section of our heart, we basically expose the four different chambers. So if we're examining the heart from this angle, we have the right side and the left side. So this is the right side of the heart, the left side of the heart, the right atrium, right ventricle, the left atrium and our left ventricle. So let's begin by looking at the different sections of the lecture cardiogram. So we have a wave known as the P wave. We have an upside down Q wave, an upside down S wave.