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 sod. 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 drug. 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 blood pressure reading that is abnormally low. Well I think that we should be a bit more persuasive about this and emphasize that. What we are referring to. Which have a range which I've done which has been established from many many blood pressure readings and blood pressure levels that are found to be above the normal range type hypertensive levels and those below the normal range high potency 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.

Hypertension refers to the blood pressure level and to. Any anxiety tension or. 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. Dunston said well this is very hard to say. There are certainly some people with high blood pressure who are nervous and anxious. And that has been suggested that some types of emotional abnormalities are associated with high blood pressure which is the cause and which is the horse or 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 and these and this particular steer 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. 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 cannot run by 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 or coerce. 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 runs that we do know. Let us divide these into various areas and let start start at the top of the of the body. Lets 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 narrowing 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 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 then 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. Cohen 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 snore adrenaline and 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 a kidney or as we call it renal hypertension is the most frequent of the so-called secondary hypertension. 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 the Ameri alone or Freitas or a pylon or Freitas which many

people still refer to as Bright's disease that 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 the murder under 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 our 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 our 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 the scope or the spectrum. Of this illness. It can range the was. Only the finding of an elevated blood pressure without any signs of disease at all 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 a has a stroke or a heart attack and that is it. Well this you could not say is 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 film a scope. They will begin to appear some haemorrhages and there may be some zing of a lot 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 talking 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 for 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. The answer to this question Mr. Phillips is going to depend upon. The person of whom you ask the question. I have no firm conviction or vested interest. And so 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 fast relationship to this. I think this probably came to pass because of the finding that hypertension could be treated by a low side. So diet 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 is 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 importantly. 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 presence in the hypertensive patients. It has been known for some time that hypertension seems to.

Arteriosclerosis. That's not good. I better get a weasel word in there. Let's just let me state the fact that the hypertensive patient is more prone to arteriosclerosis than the patient of the same age who has 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 arterial sclerosis. 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 process 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. dusty 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 taught by physicians that they have low blood pressure and the patient oft times I regret to say this the physician. I hope to relate their symptoms of anxiety and easy fatigue ability to a low blood pressure level. This is too bad because the normal range of blood pressure is so broad that right a 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 hypotension either since 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 postural 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 on 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. And 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. Now 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 the field and have helped to define the types of hypertension that come from renal artery disease. Dr. Page you know here at the Cleveland Clinic have worked 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 and discussing hyper and hypo tension. Next week you will hear Dr. John Kinross write the 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 of E.B. Radio Network.