ARTERIO-SCLEROSIS: ITS NATURE AND ITS CAUSES
The thickening chiefly of the middle coat of the arteries that we find
in this disease is the first pathological sign, and it implies that
morbid structural changes have begun; but long before this occurs, the
predisposing causes have been at work. The actual structural change
is the visible effect of the law that over-use of a muscle produces
over-growth or hypertrophy. This is not a law of disease, but of
purposeful utility, designed to meet emergencies of life. Still there
is a further law in nature, that long-continued excessive use of any
muscle leads to a form of hypertrophy which cannot maintain its
vitality, but degenerates. Arteries must be treated as muscles, for
their muscular coats contract and dilate, as circumstances demand,
under the control of the nervous system.
Dr. George Oliver, in his third edition of _Studies in Blood Pressure_,
among his fundamental data lays down this law:
“Though the left ventricle--dispensing its blood under a high pressure
into the aorta--is the master hand in maintaining the arterial blood
pressure, the height to which that pressure rises depends primarily
on the resistance encountered in the peripheral arterial system, and
in the capillaries, and, secondly, on the response of the ventricle
to overcome that resistance. Given a normal ventricle the arterial
tonus largely determines the ventricular response and the level of the
arterial blood pressure; and this is the keynote of the physiological
and pathological variations of that pressure.”
Arterial tension may be described thus: During the resting-time of the
heart, between each beat, the circulation of the blood is maintained by
the contractile power of the arteries, which steadily urges the blood
onwards into the capillary vessels, and so into the veins. This power
is known as arterial tension or pressure, and it is estimated fairly
accurately by the sphygmomanometer. A large number of observations have
taught us what is the average pressure at different ages of life, and
thus we are able to talk about a normal or abnormal pressure.
If we hope to understand and successfully treat abnormal pressure
and sclerosis, we must visualize the whole of this picture clearly,
wisely, and in its due proportions. This we have not always done.
The heart man, as Osler wittily said, “tinkers at the pump,” while
the pressure man, with his manometer, concentrates on the pipes. To
give a scientific description and explanation of the physics of the
circulation is far beyond me, and would be inappropriate in a small
practical work of this sort, but a study of some elaborate standard
work, such as Sir Clifford Allbutt’s _Diseases of the Arteries_, or
Halliburton’s _Physiology_, would do much to give a fair understanding
of this intricate subject: but, as they so often acknowledge, the
vital problem of the circulation, with its ever-changing demands, both
general and local, can hardly be solved by the known laws of physics.
Heat and cold, joy and grief, anger and fear, acting through the nerves
of the vaso-motor system, all help to complicate the problem and often
to confuse cause and effect.
As far as we can as yet judge, the first objective symptom that
points to threatening sclerosis is a more or less continuous rise of
systolic pressure, as measured by the sphygmomanometer (the use of this
instrument is imperative). The following extract from the _Lancet_
January 8, 1916, puts the matter very clearly: “The clinical value of
observations on Blood Pressure is doubted only by those who have never
made them. It is true that the finger can detect some difference in
pulse tension, but it is often entirely at fault, since it can only
estimate total pressure, thus missing a high pressure, if the volume
be small. In the same way, although the hand can detect differences of
temperature, it cannot replace the thermometer. The sphygmomanometer
has enlarged our ideas, cleared up difficulties in diagnosis, and
helped in prognosis. This has naturally reacted on treatment; it has
enlarged our ideas on ‘heart failure.’ The heart is adjusted to work
at certain pressures, and though within considerable limits it can
adjust itself to variations, those limits may be exceeded.”
There are subjective signs, especially in middle age, which point the
same way, but we can seldom get hold of patients at this early stage.
These are chiefly shortness of breath, on slight exertion, which makes
a man realize that he has almost suddenly got out of condition, that
the elasticity of youth has gone; a feeling of brain fatigue, quite
out of proportion to the work done; sometimes giddiness and tinnitus,
especially on stooping. Whether these symptoms appear before there is
a rise of pressure it is difficult to say, but they should certainly
in all cases suggest blood pressure testing. The key to the patient’s
future then lies first in our hands, and then in his, life or death,
health or disease, a full working life and happiness or incapacity
and failure. The examination must be carefully made and frequently.
The best time to take pressure is about two hours after food, when
there has been a time of physical quiet, and no hurry or emotion. The
position should be either recumbent or sitting in a chair, with the arm
resting on a table (the muscles of the arm should not be in action),
and the wrist should be on the same level as the heart. Pressure
readings are higher when standing than sitting, and when sitting than
lying down, the difference being from four to eight millimetres. In the
early stages pressure varies a good deal, and will not show a rise at
all times of day; in the early morning particularly it is often quite
normal.
The question now arises, What is the normal? For our purpose we may
leave out the question of pressures in childhood and early life, and
may take the following figures as a fair average for our calculation:--
From 40 years of age to 50, 130 mm. to 135 mm.
50 " " 60, 135 mm. to 145 mm.
60 " " 70, 140 mm. to 150 mm.
I think there can be no doubt that there is a period, often of months,
when there is only increased contraction of the muscular coats of the
arteries. This is due to the increased strain of life generally, and is
in consonance with our experience generally of muscular overgrowth and
overwork. Huchard called this “the pre-sclerotic stage.”
I think we may say that any pressures at about fifty years of age
below 120 mm. are a sign of debility, and above 150 mm. are signs of
threatening arterial trouble. Over sixty there is a natural tendency
to hardening of the arteries, and many men seem to lead healthy lives
with a pressure of 160 mm. Still, with a pressure of that height
they cannot afford to put any excessive strain on their arteries. At
about eighty there is a decided tendency for pressure to fall, even if
there has been plus pressure before. It is rare to find high pressure
over ninety for the reason that people who live to that age must have
had healthy hearts and arteries all the time, but even in them we not
infrequently find passing rises; these are often missed, but they
cause much mental distress and even delusions, but at this age, under
treatment, the pressure soon falls and the mind clears. I had one lady
who lived to ninety-seven, and during the last six years of her life
she had visions and slight delusions when her pressure rose, but in the
intervals her mind was quite clear. She learned to recognize the cause
of her trouble.
This rule of normality stands pretty true for the majority of people,
but in practice we find a good many individual exceptions: in such,
the personal equation has to be solved. Women often, even in advanced
age, have very low pressures, even 120 mm. to 125 mm., and seem to
carry on quite well. They again get a period of high pressure about
the climacteric, which with careful treatment disappears, and their
subsequent years from about fifty-five to seventy-five are often the
best and the happiest working years of their lives. It is not uncommon
both in men and women who have led strenuous but healthy lives to find,
about sixty, steady pressures of 160 mm. to 170 mm., without causing
any symptoms of illness or distress. These people, though one cannot
consider them safe lives from the insurance point of view, have learned
to manage themselves and seem to have set up a new, personal normal
which is an effective compromise. If one has been able by careful
observation to satisfy oneself about such a case, it would certainly
be unwise to try to lower that pressure point. Even in cases where
there is manifest disease of some standing, one has to find out the
best working point of pressure for the individual. They can live and
work fairly comfortably at 160 mm. or 170 mm., but if you lower the
pressure to 140 mm. or 150 mm., their hearts get irregular and they
feel good for nothing; but I think we may make a working rule that
a pressure of 180 mm. and over should be lowered; the danger to the
cerebral arteries is too great. Even in the early stages a careful
watch should be kept on the kidneys. If albumen appears, it makes the
prognosis more grave, but it should cause no despair. Mahomed and the
early observers thought that kidney disease was almost inevitable
sooner or later, but further experience has shown us that many cases
live for years and then die without albuminuria. In other cases it is
often transient and responds to treatment.
Hitherto I have only dealt with systolic pressure, but the diastolic
pressure in senility and sclerosis is a matter of much importance, and
helps us both in treatment and prognosis. Brunton said: “The systolic
pressure shows the maximum height to which blood pressure is raised
by the wave of blood driven into the aorta by the contraction of
the left ventricle. It thus indicates in a general way the strength
of the ventricle. The diastolic pressure shows the minimum to which
the blood pressure sinks during the interval when no blood is coming
into the aorta from the heart, and the arterial system is emptying
itself through the capillaries into the veins. It therefore indicates
generally the degree of contraction or relaxation of the capillaries.”
For practical purposes we want to know the pulse pressure, and this
is roughly estimated by subtracting the diastolic from the systolic.
A systolic pressure of 140 and a diastolic of 100 would give a pulse
pressure of 40, which is about right. Any pulse pressure of over 40
points to hyper-tension, and under 20 to hypo-tension. The diastolic
pressure is more constant than systolic pressure, and is not so
susceptible to disturbing external influences; it is therefore a surer
guide in estimating hyper-tension. A continuous diastolic pressure
of over 100 certainly points to continuous hyper-tension. If the
difference between the systolic and the diastolic is normal, about 30
to 40, we may conclude that the heart’s impulse is normal, and that
even in conditions of marked sclerosis there is efficient compensation.
Sir Clifford Allbutt says (in _Diseases of the Arteries_, vol. i,
p. 92): “It is in the experience of us all that, as the walls of the
great vessels lose their elasticity, the systolic pressure mounts above
its proportion to the diastolic which falls. In aortic regurgitation
the difference between the systolic and diastolic figures may be
enormous, as much as 105 mm. to 210 mm. In a certain ‘Adams Stokes’
case of my own, at a pulse rate of 32, the systolic pressure was
180, the diastolic 90 mm. Thus, with the difference between the two
pressures waxing as the resilience wanes, the blood pressure moves
more suddenly and largely, bangs more, and thus racks the machinery.
The greater vaso-motor lability in youth has a like effect, but the
vessels are then much more resilient and energy is stored. In an early
hyperpietic, or nephritic subject the systolic exorbitancy may be
considerable or variable, while the diastolic is steadily in excess.
As age advances the amplitude increases to 80 and upwards; a systolic
pressure of 160 mm. may be associated with a diastolic of 75 mm. or
80 mm.”
Dr. H. C. Mann says: “That as compensation fails, the diastolic
pressure begins to fall, and the systolic becomes irregular.” It must
seem very difficult for a beginner, or even for an experienced busy
practitioner, to find his way through all these devious by-paths, which
must look to him often to be blind alleys and to lead nowhere, but out
of the welter a few good and sound working principles emerge.
“_Firstly_, that at middle age and afterwards the knowledge of an
habitual systolic pressure is of first-rate importance.
“_Secondly_, that this knowledge can be confirmed and sometimes
rectified by knowledge of the diastolic pressure (manifest valvular
diseases of the heart, especially aortic regurgitation, are excluded);
and that a continuous rise of systolic and diastolic pressure point
conclusively to threatening or confirmed arterio-sclerosis.
“_Thirdly_, that a steady ratio between the two pressures, even
when much above normal, is a sign that the heart is doing its work
well; and conversely, a falling diastolic ratio is a sign of failing
compensation.”
Dr. Louis M. Warfield, in his work on Arterio-Sclerosis, says: “It is
most important to estimate accurately the diastolic pressure as well
as the systolic, for only in this way can we obtain any data of value
regarding the driving power of the heart and the condition of the
vaso-motor. A high systolic pressure does not necessarily mean that a
great deal of blood is forced into the capillaries. Actually it may
mean that very little blood enters the periphery. The heart wastes
its strength in dilating constricted vessels without carrying on the
circulation adequately. The pulse pressure is the difference between
the systolic and diastolic pressure, and practically represents the
heart lode.”
All these considerations demonstrate the importance of watching closely
the pump as well as the pipes.
In the above figures I am presuming that the auscultatory method of
determining pressure has been used. It must also be manifest that, the
earlier treatment begins, the more sure will be the success. It may be
that all our theories will meet the ultimate fate of so many others and
be abandoned, or partially disproved, but the practical therapeutic
results will remain--an increased capacity for work and considerable
prolongation of the later years of life.
For a short and graphic description of the two methods of estimating
pressures I am poaching from an excellent book called _Blood-pressure
Technique Simplified_, by Dr. W. H. Cowing, of America (pp. 12–15):--
“There are two methods of determining blood pressure, that by
oscillation, and that by auscultation.
“We will first describe the method by oscillation.
“Place the bag over the arm with the two tubes well under the arm and
over the brachial artery. Wrap the remainder of the sleeve around
the arm much the same as you would apply a bandage, tucking at
least six inches of the sleeve under the last fold. Then place the
sphygmomanometer in one tube and the bulb in another, and you are ready
for reading. Care should be taken not to put the sleeve on tight enough
to cause any apprehensive feeling in the patient.
“Place the finger lightly over the radial artery and send the pressure
in the cuff to the point where the pulse has entirely disappeared,
then advance the hand about 2 cm. above this point of disappearance,
then release the air gradually and note the first perceptible pulse
wave felt by the palpating finger at the wrist. This represents the
true systolic or maximal pressure.
“Having now obtained the systolic or maximal pressure, release the air
gradually by means of the escapement valve, and note where the largest
oscillation or movement of the hand takes place, and the lowest point
of this largest oscillation is the diastolic or minimal pressure.
“For example, if the largest oscillation occurred between the divisions
90 to 96, 90, being the lowest, would be the reading.
“It is well to bear in mind to keep the eye concentrated on the scale
divisions, for the travel of the hand can be accurately determined when
this is done.
“In determining systolic (maximal) pressure, the pulse becomes more
feeble as the pressure advances, and when taken with the ends of the
fingers, the pressure of the fingers is involuntarily increased, so
that a very sensitive pulse may be closed off entirely by the finger
pressure; while, if taken with the ends of the fingers resting on the
upper curve of the bone of the wrist, permitting the balls of the
fingers to rest lightly over the radial, thus bringing in contact with
the pulse the most sensitive part of the fingers, any extra pressure
that might result would be directed against the bone and not the pulse.
“_Method by Auscultation._--This is by far the most accurate method
of determining the blood-pressure, and the results obtained in this
way should be free from error, or the dangers of personal equation in
palpating the artery at the wrist.
“_Systolic or Maximal Pressure._--Bare the arm and adjust the sleeve
well up; place the stethoscope over the brachial artery about 1 cm.
below the border of the cuff, then constrict the arm by inflating the
bag until no sound is heard in the artery through the stethoscope. At
this point release the air slowly by means of the escapement valve, and
soon a clear, clicking sound will be heard, which indicates the first
passage of the blood stream below the constricting arm band and is the
true systolic or maximal pressure.
“_Diastolic or Minimal Pressure._--Still gradually releasing the air,
this clear, clicking tone (first phase) is followed by a low tone or
murmur (second phase), and this murmur is followed by a loud, clear
tone (third phase), this in turn by a perceptibly dull tone (fourth
phase), and this dull tone represents the diastolic or minimal pressure.
“Below are given the five different phases of tone to be heard in the
auscultatory blood-pressure phenomena as found by Louis M. Warfield,
A.B., M.D., and confirmed by his clinical observations on animals.
“The first phase is due to the sudden expansion of the collapsed
portion of the artery below the cuff and to the rapidity of the blood
flow. This causes the first sharp clicking sound which measures the
systolic pressure.
“The second, or murmur and sound phase is due to the whorls in the
blood stream, as the pressure is further released and the part of the
artery below the cuff begins to fill with blood.
“The third tone phase is due to the greater expansion of the artery and
to the lowered velocity in the artery. A loud tone may be produced by
a stiff artery and a slow stream or by an elastic artery and a rapid
stream. This tone is clear cut, and in general is louder than the first
phase.
“The fourth phase is a transition from the third, and becomes duller in
sound as the artery approaches the normal size.
“The fifth phase, no-sound phase, occurs when the pressure in the cuff
exerts no compression on the artery and the vessel is full throughout
its length.”
He also says that blood pressure always depends on four factors, viz.:
1. Cardiac energy.
2. Peripheral resistance.
3. Elasticity of the arterial walls.
4. The amount of blood in circulation.
It is very important to remember these and to give due value to each
of them. With regard to No. 4, it is doubtful if this is of as much
importance as has been thought or as one would at first think; the
mass of blood in the body has such a large reserve of stowage room in
the muscles and in the internal viscera, that its effect on general
arterial pressure must be slight. The viscosity of this fluid is
probably of far more importance. If one bleeds a case of high pressure
freely, the pressure will fall, but only for a short time; the blood
is thinned, but the loss in mass is quickly restored by absorption
from the watery tissues of the body, and in a very few days the
viscosity returns to its former point. Bleeding is thus very good for
emergencies, such as threatening apoplexy or cardiac dyspnœa, but is of
little permanent use in the routine treatment of high pressure.
Sir Clifford Allbutt, wisely and correctly, I think, divides most
examples of abnormal high pressure into hyperpiesis, which describes
this symptom alone, and into senile atheroma. Clinically this is
important, for hyperpiesis, which generally comes on about fifty to
sixty, is a very serious disease, which, untreated, destroys life in a
few years, whereas senile atheroma may go on till advanced old age,
crippling energy perhaps, but in many cases hardly shortening life
at all. The former generally ends in cerebral hæmorrhage, cardiac
degeneration or Bright’s disease, but senile atheroma may escape all of
these. In hyperpiesis raised pressure is continuous and tends steadily
to increase; in atheroma there are times of high pressure, but as the
disease advances the pressure is often normal or subnormal, its gravity
depending much on the seat of the atheroma.
Are we justified in regarding arterio-sclerosis as a true disease? I
think not. One cannot justly compare it with entity diseases, such
as the acute infections, as cancer, as tuberculosis, or the diseases
that affect the brain and the spinal cord. It is, I think, one of the
penalties of an artificial over-civilization, of social, business and
competitive pressure, unwise in quantity and unscientific in method.
Unfitted, as yet, in development, and lacking the necessary knowledge,
men strive after a higher stage of evolution, or after illusions
which they think to be so. For a while they seem to succeed, but
involution and premature degeneration are the inevitable consequences.
To attain their “ambitious” ends they live and work intensely, stoking
their furnaces with far too much food, alcohol and other unnatural
stimulants. Intemperate in work, intemperate in living, prodigal in
waste, they come to an untimely end.
Such is the description of one type of case that we often meet, but
there is another and a sadder class, where unfavourable circumstances
through the greater part of life, pressure of poverty and ceaseless
anxiety for others, produce a careworn existence, with no joy or
colour in it, and often insomnia. Such as these, in spite of a sober,
abstemious life, often get sclerosis. Their pulses are small and
thready, but hard, and often deceive the finger. Paralysis from small
cerebral hæmorrhage is the frequent end. We may take it as an axiom
that happiness lowers pressure, while grief and care raise it. We must
all of us feel this as a personal truth, though we may not be able
to test it with a manometer. It is not only the cat that care kills.
In melancholia the pressure is almost always well above normal; in
maniacal conditions generally below.
Few of us know how to work with our brains; psychology has as yet
taught us but little of method and of practical value, though for this
we must blame ourselves rather than the psychologists. We drive our
conscious minds with few or no intervals of rest till brain exhaustion
comes; then the machinery gets out of control and the screw races;
so come insomnia and poor, confused results, with disappointment and
depression. We talk glibly about the sub-conscious mind, and are now
and again struck with some evidence of its working existence, but we
few of us use it systematically as our servant--the most competent
servant that exists, and one that never gives notice as long as life
lasts. Our upper story, in which we suppose our conscious-thought
machine works, is like a loft full of noisy machinery that often needs
oiling and that often gets out of order. Its physical motor power gets
slack or runs right down, and the output is poor or ceases. Sleep and
rest alone will restore it and set it going again.
Our sub-conscious mind seems to be almost independent of our physical
life; it works more or less continuously while the conscious mind is
working, fooling or sleeping. To continue the loft simile: beneath the
machine loft, with its clatter and dust, is a quiet darkened room, in
which our sub-conscious mind lives and functions in its own quiet
way. Men who know how to use it say that, when their conscious minds
become exhausted and have come to an impasse, all they have to do is
to open the trapdoor and pass the apparently insoluble problem down
into the quiet room below. They then banish the subject from their
minds completely, rest, play, or take up some other line of thought,
and by and by, in a day or two perhaps, when they are not thinking of
it, the problem turns up solved. There is no sense of fatigue or of
conscious effort in this process: it is just the old adage of sleeping
over a difficulty. Many of the world’s great inventors have, knowingly
or sometimes unknowingly, made their great discoveries in this way.
Our conscious minds are limited in motive power and always subject to
fatigue, but our sub-conscious minds rarely tire and are unlimited in
scope and power, for they are a part of our Divine inheritance, a
portion of the great undivided spiritual force that moves and governs
the universe, that slumbers not nor sleeps. To get into close touch
with this power needs persevering practice, but it is clearly of
inestimable value. We must not expect a clear and useful response
unless we have given concentrated attention to the matter in point;
a mass of ill-digested, uncertain data will remain as such; we must
be perfectly honest with our _alter ego_; it is of no use trying to
take him in. The more often and thoroughly we accustom what we call
ourselves and our sub-conscious minds to work together in a friendly
way, the better and the quicker will be the response.
The above is only a cursory sketch of a profound subject, but will
serve to show what great economies can be made in the working of our
limited human understandings.
The condition of our arteries that we call sclerosis is much more
common in the sedentary brain-worker than it is in the outdoor man. We
see it rarely in the farmer, the sailor, the labourer, unless it is as
the result of habitual intemperance; we see it rarely in the athlete.
The average blood-pressure of the indoor worker is certainly higher
than that of the open-air worker, even in perfect health.
It follows, therefore, that the more we systematize and economize
in our brain work, the less the strain on the arteries that supply
that organ with its life-blood. Few of us realize what can be done in
this direction. A much advertised system, which I need not further
particularize, has got hold of some of the right ideas and methods, and
its teaching will have a big effect in many directions. It is no new
system; like almost all wisdom, it comes from the East. The old Hindu
and Persian philosophers knew and practised it thousands of years ago,
and got results which we have not approached as yet. The foundation is
concentrated attention: we talk about giving attention to a thing, but
we most of us do it in a very perfunctory, superficial way. Kipling’s
_Kim_, which is full of old, out-of-the-way, unsuspected philosophy,
gives us a wonderful picture of concentrated attention in the contest
of observation and memory between Kim and the native boy in Lurgan
Sahib’s shop. We talk admiringly of a man with “singleness of purpose,”
but what is that but concentrated attention? We admire him because
he achieves his object, he gets there, while the ordinary man with
half-a-dozen half-concentrated purposes wanders down all sorts of side
ways and seldom arrives anywhere. In this world of keen competition
and of little leisure, waste of brain-power leads inevitably towards
disease and failure, while economy leads to health and attainment.
Beyond the question of the nature of our mental work lies the thing
worked for--the object: the importance of this from the health and
disease standpoint is very great. If the object is a worthy one,
something of use, something elevating, not only for ourselves but
for others, attainment will bring happiness and peace, and so tend
towards a healthy condition of brain. If, on the other hand, we strive
for an ignoble, selfish object, one that is almost certain to harm
others, attainment will be like Dead Sea fruit in our mouths, dry and
unsatisfying; there will be in us no sense of joy, and the injury we
have done to others will recoil on ourselves, bringing disappointment
and sorrow. These are they who walk in slippery places, while the
unthinking world, seeing not their end, regards them with envy.
By learning to use our minds wisely, intelligently and economically, we
shall accomplish far more and with far less expenditure of force; we
shall grow in the true philosophical love of a high and simple life.
The false aims, the conflicts, the disharmonies of this world will pass
us by and leave us at peace.
Arterio-sclerosis, then, except in the sad cases of heredity, is very
much of our own making; it almost comes under the heading of “an
occupation disease”; it is a natural result of non-natural conditions
of life. In the words of Isaiah: “Wherefore do ye spend money for that
which is not bread, and your labour for that which satisfieth not?”
Writers have for descriptive purposes, and in most cases rightly,
divided arterio-sclerosis into the two main types that I have described
on p. 50--the hyperpiesis type and the atheromatous; but in general
everyday practice we shall often come across cases that fall under
neither head. Raised blood pressure, even to a considerable degree,
170 mm. to 180 mm., is frequently a temporary affair only, brought
about by temporary causes, such as grief, anger, excitement or
injudicious feeding. An altered mental outlook or a dose of calomel may
banish it quickly; these cases are functional only. The wiser ones get
to recognize their symptoms and the causes: these symptoms are chiefly
a worried state of mind, irritability about little things, a sense of
brain hurry, without the power to accomplish, and there may be passing
vertigo and tinnitus. Such is the day of small things which should
never be ignored, for the day of small errors unheeded may pass on into
the long night of disease.