A Typical Patient – Cardiovascular Disease

00:00 So, here’s our patient, Mr. AB. He’s got a pretty typical story for angina pectoris. I would like to get some more information from him though. For example, does he have risk factors for atherosclerosis? We have talked about this a number of times in earlier lectures. Does the patient have high blood pressure? Does he have high cholesterol? Does he have diabetes mellitus? Is he a cigarette smoker? Cigarette smoking markedly increases the risk for coronary heart disease and for stroke.

00:33 In other words, it increases the risk for atherosclerosis. Does the patient have high blood lipids? Is he obese? That is, has he got a big stomach bulging out in front? Does he have high LDL cholesterol that, in part, is related to a diet rich in saturated fat and calories and lots of sugar, lots of carbohydrates? Also, what’s his blood pressure? Is his blood pressure elevated? And in fact, we are going to then move, having taken a history, we have found that Mr. AB has some risk factors. He is a smoker, he has high blood pressure and in a moment we are going to check his lipids to see what they are. But first, we are going to do an examination on him. When we do the examination, as you can see, he does have high blood pressure, at least at that moment in the office. Often we will want him to check some blood pressures at home to make sure that this wasn’t just the excitement of the office visit that caused that high blood pressure. At least here, it’s 155- 165/ 90 mmHg. That’s markedly elevated. Remember, the normal’s 120/80 mmHg. In an older person, we might tolerate systolic blood pressure up to... into the 140s, but for a man in middle age like… like Mr. AB, this is high blood pressure. But, in addition, when we listen to him, we hear a systolic murmur. Now, what are systolic murmurs? Systolic murmurs tell us that there’s turbulent blood flow somewhere in the cardiovascular system. In this case, turbulent blood flow coming out of the heart. The location of the murmur and the quality of the murmur tells us, “Oh, I think this man may have aortic stenosis.” As we are going to hear in the valvular heart disease lecture, atherosclerosis is a major cause not only of narrowing in the blood vessels in the heart, but it also contributes to hardening and thickening and calcification in the aortic valve. Remember? That’s the valve that leads from the left ventricle out into the aorta. And that this narrowing in the aortic valve actually imposes a great extra workload on the ventricle because it has to squeeze extra hard to get blood out into the aorta. This is a very easy-to-diagnose murmur with your stethoscope and let me show you what it sounds like. It sounds a little bit like this: “HOHM, HOHM, HOHM,” as opposed to the normal person’s heart, which is, “Lub-dub, lub-dub, lub-dub.” In this patient, you will hear, “Lub-CHUH, lub-CHUH, lub-CHUH.” So, you can see that this sound is telling us there’s some obstruction in the cardiovascular system. Aortic stenosis, as you will learn in the valvular heart disease lecture, is the commonest valvular heart disease.

03:28 It’s extremely common in elderly individuals who, of course, also have a lot of atherosclerotic disease. In addition, you also notice that this patient has a little swelling in their legs, so called “peripheral edema.” This swelling is actually a sign that the cardiovascular system is under stress and that it’s retaining salt and water in excess of what should be done by the body under normal conditions and some of that excess fluid and water gets into the legs. We will also talk, when we do the lecture on heart failure, that sometimes that excess fluid gets into the lungs and makes people markedly short of breath.

04:08 So, now, we have put it all together and it appears to us that this patient has atherosclerotic coronary artery disease with narrowings in the coronary arteries. He has risks for atherosclerosis, he has symptoms that are suggestive and he has findings on physical exam that suggest, “Hey, maybe it’s not just narrowings in the coronary arteries, but even a narrowing in the aortic valve.” And so, we are going to move on to do some confirmatory tests. But, we have already got pretty good idea that this is a patient with atherosclerosis, probably with a fairly significant aortic stenosis and he may well also have coronary artery disease. Well, let’s see. Okay. So, we are going to do some… the simple tests first. We do an electrocardiogram, we do a standard chest x-ray and then we do an echocardiogram where we actually can see the aortic valve. And if the echo confirms that we are seeing some aortic stenosis, we may even go on to do a cardiac catheterization. If there were no aortic stenosis, but the patient had the same symptoms, we might do a stress test to confirm that we are seeing lack of blood flow in the heart during exercise. And of course, we are going to be doing some blood tests.

05:34 We are going to be looking - is the kidney function normal? Is the patient anemic, that is do they have enough red blood cells? And of course, we are going to be looking at lipids. And in fact, when we do the lipids in Mr. AB, no surprise, they are markedly abnormal. You can see his total cholesterol is elevated at 249… we like to… mg% We like to see a value that’s under 200 mg%. You will see that he has an elevated LDL cholesterol. Remember, we like to see that number 70 or 80 or certainly under 100, his is quite elevated. And he also has a low HDL cholesterol. So, he has a low good cholesterol and his triglycerides are a little bit slightly elevated, but not significantly so. So, his major issue - he has hyperlipidemia of the type with a high LDL cholesterol and a low HDL cholesterol, the pattern which is also associated with the atherosclerotic process.

06:39 We, of course, have done… the other blood tests are okay. The chest x-ray is all right, doesn’t show us anything very exciting. The cardiogram shows a little bit of thickening of the left ventricle, perhaps because of the aortic stenosis, but most important, the echo shows us quite severe aortic stenosis and his left ventricular ejection fraction, that is the percentage of blood that the ventricle squeezes out with each beat is actually low.

07:06 What’s a normal value? Somewhere between 50 and 55 percent. He’s slightly reduced at 45%. This is not uncommon in patients with aortic stenosis. Why? Because the ventricle is working harder against the resistance of the stenotic aortic valve. He also has some hypertrophy that is some thickening of the heart muscle. So, this confirms our initial thinking from the office visit. Now, of course, what are we going to do about this? Well, we know as cardiologists that aortic stenosis, and particularly, if there’s aortic stenosis complicated by coronary disease, can be a fatal condition. In fact, if untreated, eventually, this will be fatal, and in fact, the patient has symptoms that suggest that he’s in a beginning of a dangerous phase of aortic stenosis, that is he’s having angina.

08:06 He’s having lack of blood flow in the heart. So, what do we do about it? Well, first we would do an angiogram to look at the blood vessels to see, do they need to be fixed at the time of surgery? We are also going to talk to the cardiac surgeons about replacing his aortic valve. These days, very elderly patients can be treated with a catheter replacement with the valve alongside of some coronary arteries stenting with balloon catheters.

08:37 But, most younger patients like this, will get a surgical procedure where we can get the maximum size cardiac valve into him and bypass any narrowed blood vessels at the same time. And here you just see a little diagram showing you where the aortic valve is - between the left ventricle and the aorta. This is going to be the valve that we think is diseased and we are going to have now a conversation with the patient in which we tell him about the risk of aortic stenosis, that it can be associated with sudden death, it can be associated with gradually worsening heart failure so that the patient is completely disabled. It is definitely something that needs to be fixed at this point in Mr. AB’s life before it progresses to some terrible, catastrophic event or severe heart failure, which may, to some degree, be irreversible.

09:33 Here’s an autopsy specimen from a patient who died of severe aortic stenosis. It’s easy to see how narrow the valve is. It’s all atherosclerotic and filled with calcium and all you see is what we call a little “fish mouth” - a little, tiny opening. That’s what the left ventricle has to contend to every time it tries to squeeze blood flow through that narrowed valve. You can see that, that kind of obstruction is going to be very, very challenging to the left ventricle. So, we then talk to Mr. AB about all of this.

10:11 We explain the procedure, you know, the angiogram. It does show that there’s a narrowing in the right coronary artery as well as severe aortic stenosis. We have him talk with the cardiac surgeons and he is sent for aortic valve replacement and a coronary bypass in which a vein is taken out of the leg and bypassed around the area of narrowing in the right coronary artery. So, at the end of the operation, Mr. AB is going to have a well-functioning artificial valve - a prosthetic valve, and he’s also going to have good blood flow going down his right coronary artery through the vein bypass.

10:48 Just to show you a couple of pictures, here’s a prosthetic aortic valve sewn into the aorta.

10:54 This is a typical prosthetic valve. By the way, patients have to take warfarin - a blood thinner, so that they don’t form clots on those little metal struts; clots that can embolize, for example, to the brain. And we have already talked about the dangers of embolism in patients with atrial fibrillation. In addition, here’s a little diagram and you can see a graft going onto one of the coronary arteries. The little yellow graft coming off of the… off of one of the branches of the aorta and into the heart around an area of narrowing in a coronary artery.

11:30 Well, so, our typical patient has his operation, he gets his bypass, he gets his valve. He does extremely well. In a healthy patient like this, the risk of him dying with the surgery is generally way down 1-2%. So, 98-99% chance that he’s going to do extremely well, get out of the hospital and return to a very normal lifestyle. However, we are going to make some changes in his lifestyle because we want to decrease the chance that the atherosclerotic process is going to continue. So, we refer him, of course, to cardiac rehab. And cardiac rehab, there he is given the idea that he needs to be exercising regularly, doing aerobic exercise, walking, treadmilling, bicycling, swimming, doing something most days that he’s feeling… he’s not sick with a cold or something. We are going to talk to him about a heart-healthy diet, which is one reduced in saturated fats and reduced in simple carbohydrates. For example, sugar and flour products. We are going to talk to him about the medicines he has to take. He has to take warfarin in order to prevent blood clots on the valve and he’s going to be taking some other drugs to help control his blood pressure and his lipids - Statin drugs, remember, from the last lecture? So, and the cardiac rehab nurses are experts at reinforcing all of these, both healthy and medical interventions which will help to prevent him from having further problems with atherosclerosis. He’s going to need regular blood tests to check on his lipids.

13:13 He’s going to need an occasional electrocardiogram, particularly if he complains of irregular heartbeats. He may need a rare chest x-ray, an echocardiogram once in a while to make sure that the valve is functioning okay. But most important, what he’s going to need is careful follow-up in which he talks to his doctor about how he’s doing, where we measure his blood pressure, we measure his weight, we measure his lipids and we make sure that he’s going to be continuing to do well.

13:40 So, then in summary, you will notice after the office visit, we went through some blood tests, we went through a cardiogram and a chest x-ray, an echocardiogram, a cardiac catheterization. They enabled us to make the correct diagnosis and this patient then got the correct treatment. Thank you very much. I look forward to speaking with you with the next lecture.