Medical research; Hypertension and hypotension

The following program is produced by the University of Michigan broadcasting service under a grant of aid from the National Educational Television and Radio Center in cooperation with the National Association of educational broadcasters. Hyper and hypotension a program from the series human behavior social and medical research produced by the University of Michigan Broadcasting Service. These programs have been developed from interviews with men and women who have the too often on glamorous job of basic research. Research in medicine the physical sciences social sciences and the behavioral sciences. Occasionally you will hear what may seem like a stranger or an unfamiliar sound. These are the sounds of the participants office laboratory or his clinic where the interview was first recorded. You will hear today Dr. Harriet P. dustman of the research department at the Cleveland Clinic and my name is Glenn Phillips. It's a fairly safe guess but everyone knows of a member of his family who

suffers from hypertension or high blood pressure. This health hazard is still one of the leading causes of death. But progress has been made through research. As to statistics will show for example from 1952 through 1957 research resulted in a decline of an average of 19 and a half percent of the deaths caused by this disease. This includes both high blood pressure with heart trouble and without heart trouble. The result was achieved largely through basic research on anti-hypertensive drugs. There is still a long journey ahead. There are still over 80000 deaths annually caused directly by hypertension. The opposite of hypertension is of course hypotension low blood pressure. Dr. Dunston defines hyper and hypotension hypertension refers to elevated blood pressure and hypotension

to pressure reading that is abnormally low. Well I think that we should be a bit more precise about this and emphasize that what we are referring to. Levels which have a range which have been which has been established. From many many blood pressure readings and blood pressure levels that are found to be above the normal range hypertensive levels and below the normal range. Hyper tense of levels in the past there has been a feeling that anxiety and high blood pressure had some correlation. However DR-DOS to suggest that this is a fallacy and rather amused me and I did a double take on it. I have hypertension refer to the blood pressure level and

to. Any anxiety tension. Nervous anxiety can occur in people with normal blood pressure low blood pressure with elevated blood pressure. The term nervous anxiety is not a reference to the blood pressure level. In answer to the question Does nervous anxiety cause hypertension. Dr Justin said well this is very hard to say. There are certainly some people with high blood pressure who are nervous and anxious. And it has been suggested that some types of emotional abnormalities are associated with high blood pressure which is the cause and which is the horse. Whether there is any interrelationship. I'm not prepared to say you may be wondering as I was if one who is a hypertensive patient should avoid stress.

We've had some interesting experiences in these in this particular sphere. I have treated a large number of hypertensive patients and they all take their blood pressures at home we have to do this because so that we can know how well the medicines are working and we have found that there are many patients patients who have no elevation of their blood pressure under considerable emotional stress and that's on the one hand and on the other hand there will be patients who whose blood pressure rises when they are subjected to emotional stress. Therefore one can only conclude that there must be at times a relationship but that this is not a hard and fast one. After all we all have to live hypertensive people as well as normal tens of people and how we are going to live and never be subjected to emotional strain is beyond my sphere of comprehension.

So I think the thing that one has to remember or think about is that. There may be a relationship but it is not necessarily a hard and fast relationship. We do not know this. We do not know the fastness of the relationship and the patient who is under treatment can not ready himself sick about not being exposed to stresses and strains because this will be a stress and a strain. Is it possible to say what the cause of hypertension is. We cannot label a cause. There are many causes of hypertension. I like to look upon hypertension as being like fever. We all know that fever has many causes. So likewise does hypertension. And I think that I can assure you right know that although we presently recognize many causes that there are other

causes that we do not yet know enough to recognize. But let us discuss the ones that we do know and let us. Divide these into various areas and let start start at the top of the of the body. Let's start with brain. Now the brain is the seat of extensive blood pressure control mechanisms. And this these control mechanisms are expressed through the peripheral nerves that go to the blood vessels. So this would be a logical place to put all types of causes of hypertension. But we are unable to do this at the moment. All we can say is that the very occasional patient with a brain tumor has hypertension and that the occasional patient with polio that kind of polio which affects the brain stem well may become

hypertensive. And likewise during the crises of acute Porfirio which is a rare abnormality in blood pigment metabolism that during these crises hypertension may occur always obvious I think that we have not defined the basic causes of hypertension that must be within the central nervous system. But for the time being we have to leave that aspect and go on. No. Young adults in children. There is an important cause of hypertension which comes from a congenital defect of the aorta which is a large but large broad fuzz hole that carries the blood away from the heart. That is the major viaduct in a sense. This is a congenital knowing of the aorta in the chest and this abnormality is called correct ation of

the aorta. This is an important cause of hypertension in young people. Now there is a type of hypertension which occurs in elderly people in which there is an elevation of the systolic blood pressure and we can go into the differences between systolic and diastolic blood pressure. Later on Mr. Philips if you want and that this is due to a loss of elastic tissue in the aorta so the vessel becomes more rigid. This is termed systolic hypertension and it is not of any great importance. However it should be mentioned. Now there are tumors of the adrenal glands that can cause high blood pressure. And the you know the adrenal gland is composed of a cortex and Amidala outside and inside o There are tumors of the cortex which can cause high blood pressure one defined at the University of Michigan if you

want me to give you a plug by Dr. Khan and referred to as primary aldosterone ism meaning that this tumor C creates a particular type of adrenal cortical hormones. Then there are other types of adrenal cortical tumors that can be associated with hypertension. So a very important although not numerically significant cause of hypertension comes from a tumor of the Madonna the inside of the adrenal gland. And this tumor is called a fee a chromosome Toma that this tumor is capable of causing hypertension because it C creates large amounts of nor adrenaline adrenaline and these are substances which cause the blood vessels to become narrow and therefore raise the blood pressure the blood pressure. The last category of the causes of hypertension has to do with the kidneys the kidneys are very

important in the regulation of blood pressure. In some way although we do not know this way. We do know is that probably kidney or as we call it renal hypertension is the most frequent of the so-called secondary hypertension zz. And when one and there are types of kidney disease there are many types of kidney disease that can be associated with high blood pressure. If there is a narrowing of the blood supply. Or. A spot in one of the major blood vessels going to run or both kidneys the blood pressure can rot. This we call renal artery disease. Then if the tissue of the kidney itself becomes affected either through luminary alone affrighted us or a pile owner Freitas which many

people still refer to as Bright's disease. There likewise can be hypertension. Now the kidney is covered by a very thin capsule and if something happens to this capsule if for instance during the course of a football injury there is a blood clot forms under the capsule. This can compress the kidney substance itself and lead to hypertension. Now this particular type of renal hypertension is very rare. The other types those associated with commercial know Freitas pounder Freitas or renal artery disease are the more frequent causes kinds of renal hypertension. I think that about sums up the causes of hypertension. These are the causes that we recognize but it must be stated that not all patients have hypertension do this cause and the greatest number of patients who are hypertensive have what we call

essential hypertension. And this merely means that we do not define. We cannot define the cause. This makes their hypertension no less real no less severe. It merely means that our research has not brought us yet to the point where we can that we know the cause of hypertension in those patients who are considered to have essential hypertension. With the varying causes of the disease is it true that there are also different forms of hypertension. Yes there are hypertension is an extremely varied disease. We probably ought to refer to it really as hypertensive cardiovascular disease we ought to include in the terminology the fact that there is hypertension that there can be heart disease and that and that there certainly is blood vessel disease. But we can paint for you very shortly the

scope or the spectrum. Of this illness. It can range from. Only the finding of an elevated blood pressure without any signs of disease at whole. And can go on from there through an elevated blood pressure with signs of an symptoms of cardiac enlargement of the heart and eventually heart failure. All right. Many many years later the development of a stroke or a heart attack or something like this but it can be a disease which carries no threat to human life or it can be one which shortens life span. Yes but shortens it by only a few years. And in the meantime the patient has not felt uncomfortable has not been ill. He has been known to have hypertension for years and then at the age of 65

66 has has a stroke or a heart attack. And that is it. Well this you could not say it's a very damaging and disastrous illness but it is part of the whole disease then you can come to a step into a disease of more severity in which these complications occur at an earlier age say the person in his 40s gets heart failure. Or he has some type of a vascular accident if we wish to call it that he gets a stroke or an infarct or or a heart attack or something like that. Or there may again begin to appear in his eyes in the back of his eyes which you can only see with a special instrument called an off Soma scope. They will begin to appear some haemorrhages and there may be some oozing of out of the blood vessels and this week these we call actually date. These may interfere with his vision so one of the symptoms of this may be blurring of vision.

Still and yet that person if treated may well live all his normal life span. Oh I'm not on top I have been talking all this time about what is called benign essential hypertension. Now obviously if the hypertension shortens life span it isn't very benign but it is still cause of this. This is presently an important designation because then we go through the most severe form of hypertension which is called malignant hypertension. This form of hypertension is manifested by sometimes serious brain damage of a very acute type. Of damage to the eyes through the development of hemorrhage is an extra date. Severe heart failure can occur and there is always the threat of kidney failure ensuing because the vascular disease the blood vessel disease is

apt to be the most severe in the kidney. So I think that one can summarize this question by saying that hypertension is one of the most very diseases that we know about that it can range all the way from an illness which is not really an illness to a fatal illness which has its total course in only a few weeks. I believe that there is a correlation between high blood pressure and salt is held by many. Dr. Dunston expressed her beliefs in this manner answer to this question which Philips is going to depend upon. The person of whom you ask the question. I have no firm conviction or vested interest. In Salt about salt as a cause of hypertension. There is a great deal of interest presently. In trying to define whether or not the amount of salt we eat in our diets

produces the large amount of hypertension that is found in our population. There have been some studies done on this. There have been results to show that this is true. But as far as I personally am concerned there is no relationship to this. I think this probably came to pass because of the finding that hypertension could be treated by a low salt salt diet. It must be remembered that in order for these low salt diet to be effective as a treatment of hypertension they must be extremely restricted as to as to salt as to sodium which is what we particularly refer to. There can be no salt in the cooking. There again there must be many foods even naturally occurring foods which must be avoided. It is a tough thing to do

and it is the important thing is to remember that this restriction must be rigid. Now to go from that. Dietary restriction which comes down to about is less than a gram a day. To go on from that or less than much less than an hour. It's a tenth of an 0 something like that. A day to go from that up to a normal salt intake of 10 grams a day. And to say that is the cause of hypertension. I cannot do this personally. There are if you'd asked the question of somebody else they would have carried on rhapsodic play I think about this relationship I cannot do what we do know a few other things if we have time to go into it. There are as you know you can produce hypertension in animals these types of hypertension we refer to as experimental hypertension. And the interesting

thing is that we as we've come to learn more about the experimental hypertension we have found their clinical counterpart. We have found their counterparts and in human beings therefore this is a very interesting and valuable research experience. We know that many of the experimental hypertension are intensified by a high salt content in the animal's diet. Are there racial and sex differences in high blood pressure. Yes there are and they are interesting ones and they should give us important leads. But there are leads that we have not yet been able to follow up. As concerns racial differences negroes are more prone to hypertension and many their hypertension is extremely severe. I think that probably the incidence of malignant hypertension which is the severe form

of hypertension is more frequent in the Negro race than it is in the white race. There are sex differences Likewise women tolerate hypertension much better than men. There are supposedly more hypertensive women but there are fewer sick hypertensive women than there are men. Therefore hypertension is more frequent in women and less severe than it is in men. It has been noted that 90 percent of all heart and circulatory deaths are caused by arterial sclerosis and hypertension. One of the relationship between these two diseases. Yes we are very interested in Archer's sclerosis as well we should be because of its association with presence in I think that is better to say present in the hypertensive patient. It has been known for some time that hypertension seems to cause arteriosclerosis. That's not good.

I better get a weasel word in there. Let's just let me state fact that the hypertensive patient is more prone to arteriosclerosis than the patient of the same age he was a normal but pressure. I think that this is the precise thing we do not know what is the relationship. Of hypertension to the development of arteriosclerosis. We can we will be able to find this out as the years go by and we are able to control a hypertensive patient's blood pressures at normal levels. Then we will then we can follow these people along. Over the years and find out the study the development of our tears grows as in this patient population. It is important but the relationship is. We do know at the present time no. Leaving high blood pressure for a moment Dr. dustman discussed Michael tension. Well you probably know my significant hypertension is very rare.

There are many people few words in there used to be I think who are turned by physicians that they have low blood pressure. And the patient and ofttimes and I regret to say this the physician. Up to relate their symptoms of anxiety and you see fatigue ability to a low blood pressure level. This is too bad. Because the normal range of blood pressure is so wrong that wrong blood pressure. As a cause of symptoms is extremely rare. The only situation that there are two situations in which I recognize symptomatic hypotension. The first and probably the most frequent comes with. What we call Addison's disease now Addison's disease is a

failure of adrenal cortical function. The dream cortex puts us to right hormones which are necessary in the maintenance of the healthy state. If these hormones are deficient because the gland is the glands are not working then one of the manifestations is hypertension Addison's disease is very rare. It does occur and it's one of its outstanding symptoms is hypertension. The only other cause of situation that I know of in which hypertension occurs is one that is associated with long standing diabetes and a situation in which the patient is unable to control his butt pressure in the standing position in the lung position his blood pressure is perfectly normal but when he stands up it fails. This is called posture or properly. Ortho static hypotension. People who truly suffer from hypertension.

All right we are apt to be dizzy. They are apt to have easy fatigue but hypertension as a as not a frequent problem for the few moments remaining in this program. Dr. Dunston discusses her research interest. Well I have done little or no work in the field of hypertension except to investigate some patients with who can't maintain their pressures when they stand up and therefore faint. I am primarily interested in hypertension. There's been a great deal of work done on this in the last. Two decades and there is certainly more to come. I'm interested in the hypertension as it occurs and I'm interested in the hypertensive disease. I think that one can summarize the last 10 years of my activity other people's activities to say that we have been interested in what the treatment of blood pressure

and lowering of pressure to normal levels means to the patient means to his future health means to his productivity. We've answered these questions reasonably well and then we can go on to other phases that the proper and successful therapy of hypertension prolongs life and returns a patient to the ill patient to productive life. But the fact that most of these drugs that we act on the central nervous system intrigues us and suggests to us what we already knew which is that the central nervous system has important controls of on the blood pressure. No I think that my current interest is what are these controls and can we define classes of hypertension which have their seat in the nervous system. Now the Past experience has shown us that the kidneys have had a great deal to do with

hypertension I have been most interested in that field. And I have helped to define the types of hypertension that come from renal artery disease. Dr. Page you know here at the Cleveland Clinic if we're very actively in this field for some years we have likewise been very interested in what happens when you give patients drugs that cause them to excrete salt and water in their pheromones. And these are so called diuretics which have meant a great deal to the treatment of the hypertensive patients. I've been very interested in this phase of it. Today we have heard Dr. Harriet dust discussing hyper and hypotension next week you will hear Dr. John Kinross right Baylor Medical Center Professor Gordon t heisted of the University of Minnesota and Dr. in IC Calloway of the Langley Porter neuro psychiatric institute in San

Francisco California as they discuss drugs and their application on the next program from the series. Human behavior social and medical research. The consultant for this program was Dr. Sibley Hudler of the University of Michigan School of Medicine and Philip speaking asking that you join us next week and thanking you for being with us at this time. This program has been produced by the University of Michigan broadcasting service under a grant in aid from the National Educational Television and Radio Center in cooperation with the National Association of educational broadcasters. This is the end E.B. Radio Network.