The pulse rate, although expected to be 12 to
16 beats slower at each comparable level of
work intensity, was only slightly changed. But
more strikingly, the systolic pressure which
had risen 35% above its resting value toward
the peak load in the control test, now increased
slightly more than only 15% above the resting
level. The resting diastolic pressure was slightly
lower than during the control test, and remain-
ed constant throughout the test. Such an insig-
nificant blood pressure response to this type of
work test has been considered indicative’ of my-
ocardial insufficiency“. Since the continuously
monitored ECG, obtained from one screening
chest lead, showed normal tracings, the test was
continued to an energy demand which had been
easily maintained during the latter part of the
training. Considering the slight decrease in hody
weight from 105.5 to 102.5 Kg. the peak loads
— pre- and post-training — were almost iden-
tical.

Following this test dizziness occurred while
taking a warm shower. Upon reclining the blood
pressure was 120/80 mm Hg, apparently very
low for this previously hypertensive individual.
Raising the legs, feeding sugar and sipping cof-
fee (the last meal had been the night before)
brought on an uneventful recovery, and the sub-
ject returned to his job. Four hours later he
again complained of light-headedness. He near-
ly fainted in his attempt to walk back to the
laboratory in an outside temperature near
100°F. A standard electrocardiogram revealed
evidence of an acute inferoseptal myocardial in-
farction (Figure 2). The patient was hospital-
ized.

Samples of venous blood drawn prior to the
clinical manifestation of myocardial infarction
revealed pre- and post-exercise elevation of the

serum glutamic oxaloacetic transaminase
(SGOT) of 85 and 120 units respectively.

i DoE we

Ficure 2:
showed a deep
present in II, Ill, aVf, V, V,

The standard electrocardiogram obtained 4 hours after the second work capacity test
Q deflection in II, Il and aVf. Positive junction displacement was
‘«, These findings were compatible with an acute infero-

septal myocardial infarction which probably involved the lateral region.

—3—



Environmental conflicts decreased in intensity
and frequency in the post-infarct period. This was
due in part, at least, to strong supportive psycho-
therapy aime’ at helping the patient understand
the genesis of his emotional disturbances. In addi-
tion, a conference held with his employers led to
measures that were instituted to improve the
employer-employee relationship without destroying
the patient’s ego and self-confidence.

A single obiique lead ECG (Figure 8) was
recorded during each test since the coronary
occlusion ‘“’, It consistently recorded a deep
Q deflection with an inverted T. No abnormal
RS-T junction displacement occurred during
work or recovery in any of these tests.

nV,

t Fi

-tim

tn .

Ficure 8:

i" 1a t me if
Post Bvewese - 2 min.

The oblique lead ECG was used to record the exercise electrocardiogram. A repre-
sentative example of tracings obtained in this patient is shown

here. There was a

deep Q deflection with an inverted T wave. These findings were comoatible with a
moderately recent myocardial infarction. During work no significant RS-T displace-

ment occurred.

DISCUSSION

The value of adequate physical activity as a
therapeutic adjunct in the treatment of an un-
complicated myocardial infarction is not clearly
defined by experimental investigation. Sub-
jective and objective improvement in such
patients participating in a physical training
program has been observed by Hellerstein.
Dalton*” reported his efforts to return 900
cardiac patients to appropriate jobs, and expres-
sed the opinion that exercising such patients
provides better results than keeping them in-
active. He emphasized, however, the great need

for quantitating such observations.

A quantitative and qualitative evaluation of
the capacity for functional adjustments to vary-
ing physiological demands appears to be as
important as the recording of the electrocardio-
gram. Much more has:to be learned about the
qualitative differences in cardiorespiratory re-
sponses to work between normal and coronary
artery disease prone individuals. One available
method is the study of the cardiorespiratory re-
actions to known work intensities. The amounts
of oxygen required have to be supplied to the
active tissue by the arterial blood. Therefore,
the determination of cardiac output and arterio-
venous oxygen difference, should render valu-
able information concerning possible differences

—38—


A re-evaluation of work capacity was ascer-
tained during the 7th week post-infarction. A
marked restoration of cardiopulmonary adap-
tive capacity became evident when compared
with the results obtained 5 weeks earlier (Fig-
ure 3). The lower heart rate and augmented
blood pressure at any given workload was indi-
cative of improved cardiac dynamics. This im-
proved response suggested that the patient could
return to his regular job.

Phase II

After resumption of his normal work, R.D.C.
began a physical exercise program and adhered
to it regularly during the following weeks. A
walking speed of 3.4 mph was selected for the
supervised work-outs on a treadmill. Again, with
alternating periods of effort and rest, gradually
increasing the former and shortening the lat-
ter, cardiovascular response to exercise improv-
ed steadily.

On occasions when the heart rate attained
rates of 140 per minute, the subjective impres-
sions about the individual’s general appearance
guided the observers in lessening or adjusting
the demands. Frequently, sweating was not ac-
companied by a healthy looking flushing of the
body surface, but by a grayish pallor. It was
because of this that the treadmill exercises were
terminated and two simple ball games intro-
duced into the training program.

180.

60:

The advantage of these games is their simplicity.
In one game a player throws a basketball (eventu-
ally a medicine ball) across a fairly high net; the
other player has to catch and to return it from the
location where caught. Throwing beyond or out of
established boundary lines, not catching the- ball,
or not clearing the net properly scores for the op-
ponent. In the second game a volley ball is hit
with the hand or fist in such a way that it bounces
from the players field across a slightly lowered
tennis net into the opponent’s field. Only one
bounce is allowed before the opponent returns the
ball in exactly the same manner. For the return
each player has the choice of bouncing the ball
back immediately or after he has played it
by either one or two additional bouncing actions
into a better aggressive position. Although these
games are undemanding in special skills, they re-

juire continuous body movements in all possible
directions and result in high energy expenditures.
By adjusting the rules and regulations to the play-
ers capacity, the games have a highly competitive
note.

This change in the training routine led to
several remarkable observations. The patient en-
joyed playing these games and worked harder
than he realized, becoming more relaxed despite
a highly competitive attitude. During play he
developed a natural peripheral vaso-dilatation
instead of the grayish pallor observed during
treadmill work. Electrocardiograms telemetered
during the games revealed that heart rates near
160 per minute were tolerated without the
slightest symptoms of distress. These high rates
were recorded when the patient played against
opponents giving him fierce competition. On the
other hand, against players with less experience,
he dominated the game and, in saving efforts,
demonstrated lower heart rates (Figure 4).

R 5 10 15

20 25 30 35 40

Time in Minutes.

Ficune 4: The heart rate responses of R.D.C. during competitive ball games against various
opponents. These continuous pulse recordings were made approximately 16 to 20

weeks after the coronary incident.

—5—



Phase II

In the hospital, activities were initially lim-
ited to bathroom privileges. Dietary intake was
limited to 1200 calories per day. The propor-
tion of saturated to unsaturated fat was not

altered.

Additional history revealed that the patient had
been under severe emotional stress during the
week prior to his infarction. It was during this
period that a chronic employer-employee conflict
reached a new peak with the patient coming out
second best, in his opinion; his son left the home
for military service in an atmosphere clouded by
misunderstanding and hostility; and the patient’s
wife and ex-daughter-in-law clashed over the idea
of possible marital reconciliation with their son.
Two days prior to hospitalization the patient ex.
perienced malaise and several episodes of epigas-
tric distress characterized as indigestion. The next
day he was observed to be ashen and sweating
while talking with his neighbors.

During the second week in the hospital the
patient was allowed to walk down the hall sev-
eral times a day. On the 15th day the biody-
namic potential, i.e., the adaptability of the
cardiorespiratory system to increased energy
demands, was evaluated with a modified work
capacity test”,

>

Blood Pressure Ventilation
iJ

Pulse Rate

This test is conducted in a manner similar to
the standard work capacity test with the following
exceptions: The treadmill speed is 2.0 mph (53.6
m/min) and walking begins on a horizontal level.
This provides a load nearly twice the basal metab-
olic rate. After intervals of 3 minutes, the tread-
mill bed is raised 3.5% each time, thus provid-
ing load increases equivalent to metabolic rates of
approximately 3, 4, etc., times the BMR. For the
appropriate termination of the test the same cri-
teria are used as in the standard work test, with
two exceptions: The experimental subject—usually
an ambulatory patient—is free to stop at any time
for any reason; secondly, the load of seven mets
(multiples of BMR) is never exceeded because a
further steepening of the slope (beyond 17.5%)
becomes too difficult to negotiate for the majority
of people in a relatively poor state of health.

Figure 3 shows that the blood pressure was
much lower than before the myocardial infare-
tion, but its gradual increase during work was
an indication of a satisfactory recovery of the
damaged heart muscle. After this evaluation the
patient was allowed to ambulate freely, and was
discharged on the 17th post-infarct day. He did
well at home and a program of regular daily
exercises was initiated several days later. Exer-
cise was performed as interval training on the
treadmill and under careful supervision its in-
tensity and duration was increased each day.

R.D.C. 54 wm

20

TIME

Ficure 3:
capacity test two weeks po
second modified work capaci

90
60 10
3 6 9 12 15 18

Opes yUeD 10g

IN MINUTES

A gradual but steady increase in systolic pressure occurred during the modified work
infarction. The diast.
test 7 weeks post-infarction showed evidence of in-

Pressure remained constant. A

creased cardiorespiratory efficiency and no evidence of any underlying myocardial

insufficiency.


Ficure 6:

Resting blood pressure, serum cholesterol and
body weight changed dramatically during the
three phases of observation (Figure 7). The
original hypertension gave way to a mild hypo-
tension as an effect of heart trauma but revert-

R.0.C. 64 wm

—_—— 4-8-63—
11-12-63 ——

Ssh 88855 e883

Pulse Rate

gga aa ee

10 15 20

TIME IN MINUTES— PERCENT GRADE

Twenty weeks of regular physical training post coronary infarction have not only
restored but improved the pre-infarct capacity for making cardiorespiratory adjust-
ments to increased metabolic demands. While work capacity, initially, was rated as
“poor to fair,” the repeat test, although not continued toward physiological limita-
tions, revealed a “good” functional potential.

ed slowly to a normotensive state which per- output, declined from 106 to 81 kg.

Ficure 7:

Systolic

3

3

mm Hg

Diastotic

Blood Pressure,

8

08 88

RDC.
84. wm

Cholesterol
mgm per 100 mi

ase

Weight Ko

The initial evaluation revealed that the patient had high blood pressure, an elevated
serum cholesterol concentration and that he was overweight. The blood pressure de-
clined during the first three weeks, but the pattern became erratic during the next
three week period. A relative hypotension persisted during the early hospital period.
Since recovery it has remained in normotensive ranges. The serum cholesterol cl nged
Jittle in the pre-infarct period. With the training and caloric restriction it fell gradu-
ally reaching @ rather constant normal level of 188 mg per 100 ml. Vigorous caloric
restriction without altering the proportion of saturated to unsaturated fat led to a
25 kg weight loss during the period of observation.

—T—

sisted. The originally elevated cholesterol value
of 280 mgm per 100 ml decreased considerably
and was 188 mgm per 100 ml on the last exam-
ination. Body weight, as a consequence of re-
stricting caloric intake and increasing caloric


AM 64-2

THE EFFECT OF PHYSICAL CONDITIONING
ON AN INDIVIDUAL BEFORE AND AFTER
SUFFERING A MYOCARDIAL INFRACTION

John Naughton

Bruno Balke

Francis Nagle
Biodynamics Branch

Approved by , Released by
Stomley A Meilad nn ft Whe
Srantey R. Mower, M.D. M. S. Ware, M.D.

Dmector, CARI Feverat Ain SurcEON

FEDERAL AVIATION AGENCY
Office of Aviation Medicine
Civil Aeromedical Research Institute
Oklahoma City, Oklahoma
January 1964



patient will work well within his range of phy-
siological capabilities. He should therefore
benefit, not suffer from such a program. The
effects of such a therapeutic approach are prob-
ably as much psychological as well as physio-
logical. The improved physiological status
should in itself promote an emotional climate of
confidence and a state of well-being. It seems
reasonable to conclude that if the coronary per-
sonality is characterized by a sense of striving
for undefined goals and a state of chronic dis-
satisfaction®®, then a program of physical com-
petition might provide tangible, realizeable
goals which, once achieved, would be satisfy-
ing. Such an approach seems more rational than
the potentially demasculinizing regimens im-
posed on cardiac patients by long-term estrogen
therapy.”

Whether or not patients treated in this man-
ner will have greater longevity with fewer com-
plications from their underlying disease than
do other cardiac patients needs further study.
We feel that longevity is just one of the prob-
lems. Is it not a more important consideration
that the patient be able to have a fruitful, mean-
ingful and comfortable existence while he is
“living?”

SUMMARY

A 54 year old white male with hypertension,
obesity and elevated serum cholesterol level
volunteered for a physical training program.
During the sixth week he became ill and a re-
peat work capacity test revealed physiological
evidences of myocardial insufficiency. The pre-
exercise SGOT was elevated. A routine ECG
four hours later revealed evidence of an acute
inferoseptal myocardial infarction.

The course of the disease was uneventful and
uncomplicated. One month post-infarct the
patient resumed a physical activity program
which provided for a slow increase in metabolic
demands compatible with his capacity. Repeat
work capacity tests 20 and 23 weeks post-infarct
showed that he responded to training in exactly
the same manner as has been observed in
normal, healthy individuals. At that time he was
normotensive with a normal serum cholesterol

concentration and near-normal body weight. The
capacity for adequate cardiorespiratory adjust-
ments to high metabolic demands was rated as
“good.”

REFERENCES

1. White, P. D., Rusk, H. A., Williams, B., and Lee, P.R.:
Cardiovascular Rehabilitation. The Blakiston Co., 1957.

2. Morris, J. N., Heady, J. A., Raffle, P. A. B., Roberts, C,
G. and Parks, S. W.: Cornary Heart Disease and Physical
Activity of Work. Lancet 2:1053, 1111, 1953.

3. Raab, W.: Prevention of Degenerative Heart Disease by
Neurovegitative Reconditioning. Public Health Reports
78:317, 1963.

4. Taylor, H, L.: Coronary Heart Disease in Physically
Active and lentary Populations. J. Spts. Med. and
Phys. Fitness, 2:73, 1962.

5. Smodlaka, V.: Interval Training in Heart Disease. J.
Spts. Med. and Phys. Fitness, 3:93, 1963.

6, Hellerstein, H. K., Hirsch, E. Z., Allen, W. C. L., Polster,
S. and Zucker, N.: Reconditioning of the Coronary Pa-
tient, A Preliminary Report. Coronary Heart Disease, pg
448, Grune and Stratton, 1963,

7, Balke, B.: Experimental Evaluation of Work Capacity
as Related to Chronological and Physiological Aging,
CARI Report No. 63-18.

8. Balke, B.: A Test of Physical Performance Based on the
Cardiovascular and Respiratory Response to Gradually
Increased Work. Proj. No. 21-32-004, Report No. 1, April
1952, Sch. of Aviation Medicine, Randolph Field, Texas.

9. Balke, B., Grillo, G., Konecci, E. and Luft, U.: Work
fapacity after Blood Donation. J. Appl. Physiology 7:231,
954.

10. Naughton, J., Sevelius, G. and Balke, B.: Physiological
Responses of Normal and Pathological Subjects to a
Modified Work Capacity Test. J. Spts. Med. and Phys,
Fitness (In Press).

11. Lindeman, R., Kyriakopolous, J. and Conrad, L.: Evalua-
tion of a new Single, Oblique Chest Lead for the Detec-
tion of Electrocardiographic Abnormalities. Am. Heart J.,
64:24, 1962.

12. Dalton, S. C.: Discussion of “Interval Training in Heart
Disease.” J. Spts. Med. and Phys. Fitness, 3:99, 1963.

13. Chapman, C. B. and Fraser, R. S.: Cardiovascular Fune-
tion in Patients with Healed Myocardial Infarction.
J. Lab. and Clin, Med., 42:794, 1953.

14. Chapman, C. B., and Fraser, R. S.: III. Cardiovascular
Response to Exercise in Patients with Healed Myocardial
Infarction. Circulation 9:347, 1954,

15. Naughton, J., Balke, B., and Poarch, A.: Modified Work
Capacity Studies in Individuals with and without Coro-
nary Artery Disease. J. Spts. Med. and Phys. Fitness
(In Press).

16. Balke, B., Naughton, J. and Sevelius, G.: Cardiac Output
and Stroke Volume within Man’s Potential Range of
Energy Expenditure. Abs. Excerpta Medica, Int. Congress
Series No. 48, Read at the XXII International Congress
of Physiological Sciences, Leiden 1962,

17. Eckstein, R. W.: Effect of Exercise and Coronary Nar-
rowing on Coronary Collateral Circulation. Circulation
Res. 5:230, 1957,

18. Cathey, C., Jones, H. B., Naughton, J., Hammersten, J. F.
and Wolf,'S.; The Relation of Life ‘Stress to the concen:
tration of Serum Lipids in Patients with Coronary

pi
Disease. The Am. J. of Med. Sci., 244:421, 1962.
19. Stamler, J. Pick, R. Katz, L. Pick, A., Kaplan, B,
Berkson, D. and Century, D.: Effectiveness of Estrogens

for Therapy of Myocardial Infarction in Middle-Age
Men. JAMA, 183:632, 1953.

—10—


between healthy people and cardiac patients.
Chapman’? '* following this approach report-
ed however that the coronary patient increased
cardiac output during work in exactly the same
manner as is found in normal individuals.

Experiments in our laboratories” have indi-
cated that an evaluation of work capacity alone
was insufficient to differentiate the “normal
healthy” man from the individual who either
had or was going to have a coronary occlusion.
This could only mean that an intact myocardi-
um, that was not acutely damaged, could furnish
the blood flow needed to meet the demands of
any submaximal work task. The suspicion
existed, however, that any acute coronary in-
sufficiency leading to a relative myocardial in-
sufficiency was apt to have an effect on cardiac
dynamics.

We thought that this effect would be reflected
in the pulse pressure and pulse rate response
recorded during the work performance. The
cardiac efficiency of a well-developed, power-
ful heart is usually expressed by greater stroke
volumes at lower heart rates. On the other hand,
in cases of general physical fatigue, in the juve-
nile growing phase and in any myocardial in-
sufficiency the heart rate is rapid and the vol-
ume of blood leaving the heart during systole
is relatively small.

As it is, the heart rate can be counted readily,
but there is no rapid, simple method available
for measuring stroke volume. However, the
observation has been made that changes in
energy demands from rest to work and during
exercise caused relative changes of blood pres-
sure quantitatively indicative of the simultane-
ously occurring changes of stroke volume’.
Therefore, the heart rate and blood pressure
pattern during the treadmill test revealed some
clues about the hemodynamic response of the
test subjects. It was assumed that the relatively
diminished stroke volume in the case of myo-
cardial insufficiency should be manifested by
only a slight increase of the systolic pressure
with increasing work intensities.

That such physiological conditions do exist
was readily demonstrated in this patient. The
initial test response (Figure 1) revealed that
he possessed a low work capacity and that he
had a sustained elevation of his diastolic pres-

sure. The response to work indicated that he
raised the cardiac output by increasing both
stroke volume and heart rate.

During the second test one would have expect-
ed to find evidence of an increased cardiac
efficiency. Instead, the physiological adapta-
tion to work was accomplished by a relatively
rapid heart rate with only a minimal elevation
of systolic pressure, suggesting the possibility
of a heretofore unsuspected myocardial insuffi-
ciency. Its existence was confirmed by the ele-
vated SGOT levels and the electrocardiogram.
The clinical history and elevated pre-exercise
SGOT indicated that the infarction had occurred
before this second test.

Whether or not the physical training hastened
the onset of or lessened the consequences of the
infarct is not known. Some investigators have

_ suggested that training may be advantageous in

lessening the severity of a coronary occlusion
by stimulating the development of increased
collateral circulation. Eckstein*” demonstrated
that exercise was a stimulus to increased coro-
nary collateral circulation in dogs when relative
coronary insufficiency had been surgically in-
duced.

The course following the patient’s uneventful
recovery was quite remarkable. He volunteered
to continue a training program. The systolic
pressure: response to low energy demands 2 and
7 weeks post-infarct (Figure 3) suggested a
more efficient myocardium than was present
during the second standard work capacity test.
The added stimulation of physical training led
to physiological effects similar to those seen in
normal healthy individuals. These’ included a
lower resting pulse rate, lowering of the blood
pressure and greater cardiorespiratory efficien-
cy. In the final standard work capacity test
there was no way to differentiate his perform-
ance from that of a healthy individual, trained
or untrained.

Several of the questions raised by the idea of
physically training cardiac patients have been
partly answered by this experiment. As suspect-
ed from an earlier report*”, the uncomplicated

asymptomatic, healed myocardial infarct patient
does react to physical training in the same man-
ner as normal individuals. In a well-supervised,
gradually progressing training program the

—9—



The next modified work capacity test was
performed 12 weeks after returning to his job.

‘The patient performed this test with ease and
had a response similar to that usually seen only
in better trained individuals (Figure 5). Pulse
rates were 20 to 40 beats per minute lower than
at identical work rates during the third week
post-infarct. Resting blood pressure was normal

60
40

with a response during work much like that ob-
served in normal healthy people. Minute ventil-
ation values of 10 to 15 liters per minute less
for any given grade on the treadmill suggested
a lessening of respiratory effort. Since this test
had not provided the intensities of work needed
to ascertain the potential adaptive capacity of
the heart, the standard treadmill test was per-
formed 3 weeks later.

R.D.C. 54 wm

aos

20
160

130
100

70
150

120
90
60

Blood Pressure Ventilation

Pulse Rate

@PBID 3USD Jed

Time in Minutes

Ficure 5: The post-trai

response to a modified work capacity test is compared with that

two weeks post-infarct. At rest there is a much slower pulse rate with a wider pulse
pressure. During work there was greater elevation of the systolic pressure with a very
slow rise in pulse rate to 120/min at the test's termination. For the first time a
decline in diastolic pressure was recorded during work. Increased ventilatory efficiency
is demonstrated by the decreased minute ventilation at each comparable work load.

The results of this test were plotted and com-
pared with the values obtained in the initial
work capacity test in Phase I (Figure 6). The
resting blood pressure was “normal.” The sys-
tolic pressure increased commensurate with
work intensities and similarly as in normal sub-
jects. The diastolic pressure showed the decline
usually observed in better conditioned exami-
nees. The response of heart rate as well as pul-
monary ventilation were evidence of improved

cardiorespiratory economy. Physiological limit-
ations were not evident when this test was termi-
nated at a pulse rate of 168/min. In view of the
disease history, no attempts were made at this
time to evaluate the maximum aerobic capacity.
Even at this level of energy expenditure a work
performance was achieved slightly superior to
the average fitness level of a normal healthy
male population, and greater than his perform-
ance capacity before the myocardial infarction.

—6—


During rest blood pressure was 162/120 mm
Hg, heart rate 80 per minute, serum cholesterol
285 mgm per 100 ml; body weight was 106 kg
and height 176 cm.

The cardiovascular and respiratory adjust-
ments to the gradually increasing work demands
are illustrated in Figure 1. The peak level of
aerobic work capacity attained was indicative
of a level of physical fitness classified as
“poor,” slightly below the average value obtain-
ed from studying a large male population.

Following this evaluation of work capacity
an interval training program was begun and ad-
hered to on 5 out of 7 days. Initially, working
and resting intervals of 30 or 45 seconds fol-
lowed each other for periods of 20 minutes;
these were gradually increased to 40 minute
periods. Exercise consisted of walking on the
treadmill at a speed of 3.4 mph on varying
grades, depending on the functional response
to given work intensities.

=

S853 oS 3

=

BLOOD PRESSURE VENTILATION

PULSE RATE
- =-=s2

The resting blood pressures recorded before
each day’s exercise slowly declined during the
first three weeks of training (Figure 7). Then,
although work capacity improved ostensibly,
these routine blood pressure measurements be-
came erratic and occasionally were close to the
original hypertensive values. No attempt was
made to establish a connection between this
cardiovascular inconsistency and any possible
interferences of a psychological nature at home
or on the job.

After six weeks of training the subject re-
turned for a re-evaluation of work capacity. He
did not look well and was not as cheerful as
usual, but insisted that he felt fine. The func-
tional response to the test task was far from that
usually seen after a period of physical training
involving increasingly greater energy expendi-
tures each day, and was also different from
measurements and observations made during
the training itself (Figure 1).

R.D.C. 54 wm

3.5 MPH

fo}

5

10 15 20

TIME IN MINUTES — PERCENT GRADE

Ficure 1:

An elevated resting blood pressure was recorded prior to the initial work capacity

test. The systolic pressure rose approximately 35% above the festing value during

the work. The diastolic pressure remained elevated. A very mi

inimal systolic pressure

elevation occurred during the second test. In addition, the pulse rate was relatively
rapid instead of being slower after the training period. These findings suggested
the existence of a myocardial insufficiency.

—2—


THE EFFECT OF PHYSICAL CONDITIONING
ON AN INDIVIDUAL BEFORE AND AFTER
SUFFERING A MYOCARDIAL INFARCTION

“John Naughton, M.D.
Bruno Balke, M.D.
Francis Nagle, Ed.D.

The value of regular physical activity in the
prevention of clinically manifest coronary ar-
tery disease has received much emphasis during
the past few years". Its place and worth in
the treatment of patients with coronary athero-
sclerosis is still an unsettled question. European
investigators have pioneered in using physical
exercise for the rehabilitation of certain cardiac
disorders. It is only recently that investigators
in this country have voiced strong opinions sup-
porting programs of physical training for many
patients with organic heart disease”.

The fact remains that basic questions concern-
ing the cardiac patient’s reaction to and capac-
ity for work are unahswered. Despite encourag-
ing reports of the beneficial effects from syste-
matic physical training on many types of heart
disease patients, there is a lack of physiological
evidence for the quality of functional responses
to work with or without training.

In this report some physiological and bio-
chemical observations recorded on an individu-
al who engaged in a program of regular physi-
cal training for the control of obesity and hy-
pertension, had a myocardial infarction, and
resumed physical conditioning after an adequate
interval of recuperation are presented.

The experimental material will be presented
in three phases: Phase I includes the physical

“Medical Department of the Oklahoma University Medical
School, Oklahoma City, Oklahoma.

Research supported in part by Public Health Service Re-
search Grant #HE-06286-03.

evaluation before a conditioning program was
started; then the progress during regular train-
ing, and the re-evaluation of work capacity after
a six-week training period. Phase II, beginning
only hours after the latter test, presents the evi-
dence of myocardial infarction and reports the
clinical and experimental data obtained from
that time until the patient’s return to work on a
part-time basis. Phase III covers the period of
re-training, its progress and its effects on the
capacity for making functional adjustments to
gradual increments in energy demands.

Phase I

The individual (RDC), a 54 year old white
male with a one year history of hypertension,
had heard about the effects of daily exercise
on blood pressure”, and volunteered for parti-
cipation in a systematic, long-range, exercise
program.

After essential measurements had been made
in the resting state the experimental subject per-
formed a standard work capacity test on a
treadmill”.

In this test procedure the treadmill speed remains
constant at 91.5 m/min and walking begins on a
grade of 1 per cent. Each minute the slope is
increased 1 per cent by tilting the treadmill bed.
Blood pressure, pulse rate and ECG are monitored
from minute-to-minute; measurements of the res-
piratory gas exchange are made every other and
during the last minute. The test is terminated at
a heart rate considered to be near maximum, usu-
ally around 180 per min, It is at this point that
the systolic pressure does not attain the previously
measured maximum height and/or a simultaneous
rise in diastolic pressure is recorded. Other indi-
cations for terminating the test are: obvious dysp-
nea, signs of pallor, claudication, or chest pain.

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