 Let's continue on and discuss how different medications can affect different measurements in patients that have angina. So we're specifically going to pair nitrates, beta blockers, and nitrates and beta blockers used together and find out how they affect blood pressure, heart rate, endostoc volume, contractility, ejection time, and myocardial oxygen consumption. First and foremost, nitrates. Nitrates work by vasodilating because of an increase in nitric oxide, which increases smooth muscle relaxation. So with nitrates, vasodilating is going to decrease our blood pressure. Beta blockers also will decrease our blood pressure, and when we combine the two together, we see a decrease in blood pressure as well. When using nitrates, the heart rate actually can go up. It's not a effect of the actual medication, but a reflex from the bottoming out of our blood pressure and a reflex increase in our heart rate for the body trying to compensate. Beta blockers, obviously, are blocking those beta one receptors. Those beta one receptors, when they are blocked, are going to cause a decrease in our heart rate. And when we use nitrates and beta blockers together, we don't see that reflex tachycardia. So we can see a decrease in our heart rate. With nitrates, because they are vasodilating, they are going to reduce our end diastolic volume. However, on the contrary, with beta blockers, because all beta blockers are doing is slowing down the heart, is they're going to increase our end diastolic volume. They have little effect on the vasculature and more effect on the actual contractility of the heart. So we will see an increase in the end diastolic volume. And when we combine nitrates and beta blockers together, we actually see a decrease in our end diastolic volume. In regards to contractility, with nitrates, as we see with heart rate, we can get a reflex increase in our contractility with nitrates. Beta blockers will cause a decrease in contractility, because that is one of the effects of blocking those beta receptors. When we put nitrates and beta blockers together, because we had a slight increase or a reflex increase in nitrates and a decrease in beta blockers, we typically are going to see little to no effect on the contractility with these two medications prescribed in combination. The ejection time with nitrates is going to be decreased. The ejection time with beta blockers will be increased. It's slowing our heart rate down. And as far as combining nitrates and beta blockers together, our ejection time has little to no effect here once again. And finally, our myocardial oxygen demand. For nitrates, we have a decrease in our myocardial oxygen demand. This is going to be important when we're talking about angina or ischemia, because we want to decrease the amount of oxygen that's needed by the tissue when we're having issues with providing oxygen to that tissue. With beta blockers, we also see a decrease in our myocardial oxygen consumption when we have a lower heart rate. The heart does not need as much oxygen, so it has a decrease in our consumption. If we combine nitrates and beta blockers together, the myocardial oxygen demand is decreased significantly. So we have a great reduction in our myocardial oxygen demand with a dual therapy, nitrates and beta blockers.