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Heart rate changes in physicians during daily “stressful” tasks
Journal
of Psychosomatic
Research,
HEART
RATE CHANGES IN PHYSICIANS DAILY “STRESSFUL” TASKS”?
GORDON
1963, Vol.
7, pp
147 to 150.
Pergamon
Press
Ltd.
Printed
in Northern
Ireland
DURING
H. IRA, JR., ROBERT E. WHALEN AND MORTON D. BOGDONOFF (Receiwd 2 May 1963)
THE
daily activities of all individuals encompass, from time to time, situations which are associated with heightened degrees of emotional arousal. We usually refer to these situations as “stressful”, and we have recognized that such feelings as anxiety, Over the past decades investifear, anger, or rage may occur during these experiences. gations of the physiologic responses that accompany intense feeling states have been made either in the laboratory during induced emotional arousal or following some actual stressful experience in daily life. The development of miniaturized telemetering equipment has made it possible for certain physiologic responses to be recorded before, during, and after, an, actual stressful situation, and this report is concerned with observations of heart rate utilizing such a technique. The subjects of this study were physicians working in this medical center. The daily activities of physicians include several experiences which may be considered to be “stressful”. For the purposes of initial observation three situations were chosen: (1) The mid-day staff conference during which patient history presentations and discussion were conducted, (2) medical student presentations of patient examinations during attending staff ward rounds, and (3) diagnostic cardiac catheterization in the cardiac catheter laboratory. These situations were accompanied by varying degrees of anxiety in all physicians, and were considered by all participants to fit the general category of “stressful”. The individual variations in the physiologic response are of particular interest, however, and form the content of this report. METHOD The method used in this laboratory for radiotelemetry of the pulse rate has been previously reported [l]. The several modifications used in this study, included the following: the electrocardiogram, after being transmitted from the subject to the central receiving station, was also recorded on magnetic tape for future playback on standard electrocardiographic paper. This allowed subsequent direct measurement of the R-R interval providing a check on the value of heart rate recorded by the cardiotachometer. For the mid-day staff conferences, the physician who was to present the patient history was brought to the laboratory prior to the conference and the electrocardiograph transmitter applied. Anterior and lateral chest leads were used and the transmitter was worn either in a shirt pocket or in a speciallyfitted holster. The heart rate was recorded during the entire hour of the conference: before, during and after the actual patient presentation. The mean rates were calculated for each period in addition to the peak change during the presentation. The medical students observed during ward rounds were recorded throughout the full morning rounds, which also included periods of time when the student was not presenting a patient history, but merely observing other members of the group. The physician performing the cardiac catheterization wasrecorded from approximately a half hour before, to the final completion of the study. Particular stressful moments during the procedure were * From the Department of Medicine, Duke University Medical Center, Durham, NC., U.S.A. I’ Supported in part by the Duke University Center for the Study of Aging (H-3582, M-2109), U.S. P.H.S. Grant HE-07563, The Life Insurance Medical Research Fund, The Walter Inman Fund, and The Irwin Strasburger Memorial Medical Foundation. 147
148
GORDON
H. IRA,JR.,ROBERTE.WHALEN
and MORTOND.BOGDONOFF
noted by an independent observer. During these observations, urine collections were also made for measurement of the excretion of catecholamines before, during, and after the cathetization. The bio-assay method of Von Euler was used to determine the urinary catecholamines [2]. Twenty-four conference presentations were monitored. Three physicians were observed on two There were 11 interns, 4 residents, occasions. The age range was 25-37 years [mean 28.6 years]. 5 fellows and one senior staff member. Twelve cardiac catheterizations by three cardiology fellows were studied, seven sessions with catecholamine excretion collections. Two ward round presentations were recorded on two medical students. RESULTS
The mean heart rate during noon conference presentation was 115, with a mean peak of 138. One physician ran a mean rate during presentation of 149, with a peak of 188. The mean rate prior to presentation was 100 and the mean rate after presentation was 85. The mean rate during cardiac catherization was 104, with a mean high of 125 and a mean low of 78. The mean heart rate during ward rounds presentation was 97 with a peak of 145 and a low of 59. Fig. 1 depicts the pattern of the heart rate for a resident during a patient presenOf particular note are the sharp rises that occur when tation at the noon conference.
FIG. 1
he brings the patient into the conference room, and then again when starting the presentation. Fig. 2 illustrates another resident during two phases of the conference: initially during the first presentation by another physician, and then later during his own presentation. The catecholamine excretion rates are summarized in Table 1 showing all values to be essentially within normal limits except for R.S., who had a high nor-adrenaline excretion rate before and during the procedure, returning to normal levels following the study. A.C. demonstrated a consistent decrease in the nor-epinephrine excretion R.W. demonstrated a slight increase in rate during the entire course of the morning. adrenaline excretion during and after the study, this being most marked during study
149
Heart rate changes in physicians during “daily stressful” tasks
I
I
FIG. 2 number three. On that day, he encountered some difficulty during the procedure. The absolute values for the catecholamine excretion rates do not, however, correlate directly with the degree of difficulty of the procedure, although there was a definite difference in the degree of experience between subjects R.W. and R.S., and the latter reported a fair degree of concern about conducting cardiac catheterizations. TABLE
1 .--URINARY
CAWCHOLAMINE
EXCRETION,
OF A CARDIAC
Subject 1.
Study No.
R.W.
1 2 3 Mean
2. A.C.
1 2 3 Mean
3. R.S.
1
BEFORE,
CATHEl
Before A* 1.18 NAT 1.48 A 1.12 NA 1.40 A 0.078 NA 0.861 A 0.91 NA 1.35 A 0.70 NA 3.38 A 0.869 NA 3.31 A 0.786 NA 3.45 A 0.78 NA 3.38 A 1.76 NA
DURING,
ERIZATION
10.90
([(g/l
AND
AFTER
THE PERFORMANCE
HR)
During A NA A NA A NA A NA A NA A NA A NA A NA A NA
1.73 1.73 1.33 1.05 1.66 2.16 1.08 1.15 0.781 2.75 0.632 2.02 0.891 2.84 0.77 2.54 6.10 9.20
After A NA A NA A NA A NA A NA A NA A NA A NA A NA
2.20 1.73 1.51 1.10 1.51 2.18 1.79 1.66 1.78 2.31 0.639 1.39 1.12 2.25 1.18 1.98 0.421 1.17
* A-Adrenaline t NA-Nor-adrenaline DISCUSSION
These observations are presented to graphically document the magnitude and duration of the heart rate responses that occur during some of the so-called “usual” task of young physicians in this medical centre. These tasks are generally considered to be “stressful” by the individuals performing them, though none of the physicians were aware of the heart rate increases that were observed. Physicians variously described themselves as “tense . . . nervous . . . anxious to do a good job . . . afraid that something would go wrong . . .” Many reported feelings of “tightening up” just before G
GORDON H. IRA, JR., ROBERT E. WHALEN and MORTON D. BOGDONOFF
150 patient voice
presentations,
and several
and extremities.
One
were
subject
aware
thought
of dryness
he noted
of the mouth,
“palpitations”.
tautness
of the
(His rate was 96
and there was no arrhythmia during the presentation.) The high heart rates that did occur-and for sustained periods of time-indicate In the interviews of to us that these daily tasks do represent “stressful” situations. physicians conducted following the telemetering observations, the usual report was that the stress was only “moderate”. The event, however, had a much more dramatic impact upon the cardiac rate mechanism. In the studies in which urinary excretion rates of adrenaline and nor-adrenaline were measured, the absolute values were not high in any study except one (R.S.). In one subject (R.W.) there was a trend for the adrenaline excretion to rise, but not to any marked degree. In view of the recent evidence indicating that the bioassay procedure will measure only a fraction of the total amount excreted [3], it may be that the method is unable to detect a significant change that corresponds to the marked change in cardiac rate. The eventual meaning of these rate changes upon the integrity of the cardiovascular system is, of course, a matter for speculation. The one clear implication of the observations of this study, however, is that these “stressful” experiences, if sustained by individuals with marginal cardiac reserve, might well anticipate discomfort if the “stress” is sufficiently prolonged. Finally, this study indicates that the methods of telemetry, as applied to the tasks of daily experience, can provide us with useful information on the physiological changes that occur during these tasks. SUMMARY Radiotelemetry recording
cians-in-training tasks
of the electrocardiogram
the heart
were
catheterization
rate during
and
recorded,
medical
so-called students.
including
by clinical
fellows,
conference
has
provided
“stressful” Observations
presentation
and ward-round
a technique
life situations during
for constantly
in a group 38 various
by staff
presentations
of physi“stressful”
physicians,
cardiac
by medical
students.
Marked and sharp rises in heart rates occurred in almost all subjects. The peakchanges were most often of short duration, but in some individuals sustained levels of tachycardia persisted throughout several minutes to over an hour of observation. Urinary catecholamine excretion rates were also measured during the performance of cardiac catheterizations and significant increases in adrenaline excretion were observed in association with the prolonged tachycardia. REFERENCES
I. IRA GORDON H., Jr. and BOCDONOFFM. D. Application of Radiotelemetry
in Man for Continuous Recording of Heart Rate. J. After. Med. Ass. 180, 976 (1962). 2. VON EULER U. S. The Distribution of Sympathin N and Sympathin A in Spleen and Splenic Nerves of Cattle. Acfa. Plrjxiol. Stand. 19, 207 (1949). 3. LABROSSE E. H., AXELROU J.. KOPIN I. J. and KETY, S. S. Metabolism of 7-H3-Epinepllrine-dbitartrate in Normal Young Men. J. Clin. Itwest. 40, 253, (1961).
of Psychosomatic
Research,
HEART
RATE CHANGES IN PHYSICIANS DAILY “STRESSFUL” TASKS”?
GORDON
1963, Vol.
7, pp
147 to 150.
Pergamon
Press
Ltd.
Printed
in Northern
Ireland
DURING
H. IRA, JR., ROBERT E. WHALEN AND MORTON D. BOGDONOFF (Receiwd 2 May 1963)
THE
daily activities of all individuals encompass, from time to time, situations which are associated with heightened degrees of emotional arousal. We usually refer to these situations as “stressful”, and we have recognized that such feelings as anxiety, Over the past decades investifear, anger, or rage may occur during these experiences. gations of the physiologic responses that accompany intense feeling states have been made either in the laboratory during induced emotional arousal or following some actual stressful experience in daily life. The development of miniaturized telemetering equipment has made it possible for certain physiologic responses to be recorded before, during, and after, an, actual stressful situation, and this report is concerned with observations of heart rate utilizing such a technique. The subjects of this study were physicians working in this medical center. The daily activities of physicians include several experiences which may be considered to be “stressful”. For the purposes of initial observation three situations were chosen: (1) The mid-day staff conference during which patient history presentations and discussion were conducted, (2) medical student presentations of patient examinations during attending staff ward rounds, and (3) diagnostic cardiac catheterization in the cardiac catheter laboratory. These situations were accompanied by varying degrees of anxiety in all physicians, and were considered by all participants to fit the general category of “stressful”. The individual variations in the physiologic response are of particular interest, however, and form the content of this report. METHOD The method used in this laboratory for radiotelemetry of the pulse rate has been previously reported [l]. The several modifications used in this study, included the following: the electrocardiogram, after being transmitted from the subject to the central receiving station, was also recorded on magnetic tape for future playback on standard electrocardiographic paper. This allowed subsequent direct measurement of the R-R interval providing a check on the value of heart rate recorded by the cardiotachometer. For the mid-day staff conferences, the physician who was to present the patient history was brought to the laboratory prior to the conference and the electrocardiograph transmitter applied. Anterior and lateral chest leads were used and the transmitter was worn either in a shirt pocket or in a speciallyfitted holster. The heart rate was recorded during the entire hour of the conference: before, during and after the actual patient presentation. The mean rates were calculated for each period in addition to the peak change during the presentation. The medical students observed during ward rounds were recorded throughout the full morning rounds, which also included periods of time when the student was not presenting a patient history, but merely observing other members of the group. The physician performing the cardiac catheterization wasrecorded from approximately a half hour before, to the final completion of the study. Particular stressful moments during the procedure were * From the Department of Medicine, Duke University Medical Center, Durham, NC., U.S.A. I’ Supported in part by the Duke University Center for the Study of Aging (H-3582, M-2109), U.S. P.H.S. Grant HE-07563, The Life Insurance Medical Research Fund, The Walter Inman Fund, and The Irwin Strasburger Memorial Medical Foundation. 147
148
GORDON
H. IRA,JR.,ROBERTE.WHALEN
and MORTOND.BOGDONOFF
noted by an independent observer. During these observations, urine collections were also made for measurement of the excretion of catecholamines before, during, and after the cathetization. The bio-assay method of Von Euler was used to determine the urinary catecholamines [2]. Twenty-four conference presentations were monitored. Three physicians were observed on two There were 11 interns, 4 residents, occasions. The age range was 25-37 years [mean 28.6 years]. 5 fellows and one senior staff member. Twelve cardiac catheterizations by three cardiology fellows were studied, seven sessions with catecholamine excretion collections. Two ward round presentations were recorded on two medical students. RESULTS
The mean heart rate during noon conference presentation was 115, with a mean peak of 138. One physician ran a mean rate during presentation of 149, with a peak of 188. The mean rate prior to presentation was 100 and the mean rate after presentation was 85. The mean rate during cardiac catherization was 104, with a mean high of 125 and a mean low of 78. The mean heart rate during ward rounds presentation was 97 with a peak of 145 and a low of 59. Fig. 1 depicts the pattern of the heart rate for a resident during a patient presenOf particular note are the sharp rises that occur when tation at the noon conference.
FIG. 1
he brings the patient into the conference room, and then again when starting the presentation. Fig. 2 illustrates another resident during two phases of the conference: initially during the first presentation by another physician, and then later during his own presentation. The catecholamine excretion rates are summarized in Table 1 showing all values to be essentially within normal limits except for R.S., who had a high nor-adrenaline excretion rate before and during the procedure, returning to normal levels following the study. A.C. demonstrated a consistent decrease in the nor-epinephrine excretion R.W. demonstrated a slight increase in rate during the entire course of the morning. adrenaline excretion during and after the study, this being most marked during study
149
Heart rate changes in physicians during “daily stressful” tasks
I
I
FIG. 2 number three. On that day, he encountered some difficulty during the procedure. The absolute values for the catecholamine excretion rates do not, however, correlate directly with the degree of difficulty of the procedure, although there was a definite difference in the degree of experience between subjects R.W. and R.S., and the latter reported a fair degree of concern about conducting cardiac catheterizations. TABLE
1 .--URINARY
CAWCHOLAMINE
EXCRETION,
OF A CARDIAC
Subject 1.
Study No.
R.W.
1 2 3 Mean
2. A.C.
1 2 3 Mean
3. R.S.
1
BEFORE,
CATHEl
Before A* 1.18 NAT 1.48 A 1.12 NA 1.40 A 0.078 NA 0.861 A 0.91 NA 1.35 A 0.70 NA 3.38 A 0.869 NA 3.31 A 0.786 NA 3.45 A 0.78 NA 3.38 A 1.76 NA
DURING,
ERIZATION
10.90
([(g/l
AND
AFTER
THE PERFORMANCE
HR)
During A NA A NA A NA A NA A NA A NA A NA A NA A NA
1.73 1.73 1.33 1.05 1.66 2.16 1.08 1.15 0.781 2.75 0.632 2.02 0.891 2.84 0.77 2.54 6.10 9.20
After A NA A NA A NA A NA A NA A NA A NA A NA A NA
2.20 1.73 1.51 1.10 1.51 2.18 1.79 1.66 1.78 2.31 0.639 1.39 1.12 2.25 1.18 1.98 0.421 1.17
* A-Adrenaline t NA-Nor-adrenaline DISCUSSION
These observations are presented to graphically document the magnitude and duration of the heart rate responses that occur during some of the so-called “usual” task of young physicians in this medical centre. These tasks are generally considered to be “stressful” by the individuals performing them, though none of the physicians were aware of the heart rate increases that were observed. Physicians variously described themselves as “tense . . . nervous . . . anxious to do a good job . . . afraid that something would go wrong . . .” Many reported feelings of “tightening up” just before G
GORDON H. IRA, JR., ROBERT E. WHALEN and MORTON D. BOGDONOFF
150 patient voice
presentations,
and several
and extremities.
One
were
subject
aware
thought
of dryness
he noted
of the mouth,
“palpitations”.
tautness
of the
(His rate was 96
and there was no arrhythmia during the presentation.) The high heart rates that did occur-and for sustained periods of time-indicate In the interviews of to us that these daily tasks do represent “stressful” situations. physicians conducted following the telemetering observations, the usual report was that the stress was only “moderate”. The event, however, had a much more dramatic impact upon the cardiac rate mechanism. In the studies in which urinary excretion rates of adrenaline and nor-adrenaline were measured, the absolute values were not high in any study except one (R.S.). In one subject (R.W.) there was a trend for the adrenaline excretion to rise, but not to any marked degree. In view of the recent evidence indicating that the bioassay procedure will measure only a fraction of the total amount excreted [3], it may be that the method is unable to detect a significant change that corresponds to the marked change in cardiac rate. The eventual meaning of these rate changes upon the integrity of the cardiovascular system is, of course, a matter for speculation. The one clear implication of the observations of this study, however, is that these “stressful” experiences, if sustained by individuals with marginal cardiac reserve, might well anticipate discomfort if the “stress” is sufficiently prolonged. Finally, this study indicates that the methods of telemetry, as applied to the tasks of daily experience, can provide us with useful information on the physiological changes that occur during these tasks. SUMMARY Radiotelemetry recording
cians-in-training tasks
of the electrocardiogram
the heart
were
catheterization
rate during
and
recorded,
medical
so-called students.
including
by clinical
fellows,
conference
has
provided
“stressful” Observations
presentation
and ward-round
a technique
life situations during
for constantly
in a group 38 various
by staff
presentations
of physi“stressful”
physicians,
cardiac
by medical
students.
Marked and sharp rises in heart rates occurred in almost all subjects. The peakchanges were most often of short duration, but in some individuals sustained levels of tachycardia persisted throughout several minutes to over an hour of observation. Urinary catecholamine excretion rates were also measured during the performance of cardiac catheterizations and significant increases in adrenaline excretion were observed in association with the prolonged tachycardia. REFERENCES
I. IRA GORDON H., Jr. and BOCDONOFFM. D. Application of Radiotelemetry
in Man for Continuous Recording of Heart Rate. J. After. Med. Ass. 180, 976 (1962). 2. VON EULER U. S. The Distribution of Sympathin N and Sympathin A in Spleen and Splenic Nerves of Cattle. Acfa. Plrjxiol. Stand. 19, 207 (1949). 3. LABROSSE E. H., AXELROU J.. KOPIN I. J. and KETY, S. S. Metabolism of 7-H3-Epinepllrine-dbitartrate in Normal Young Men. J. Clin. Itwest. 40, 253, (1961).