Chest Pain References
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Angina-like esophageal pain: differentiation from cardiac pain by history.
Davies HA, Jones DB, Rhodes J, Newcombe RG
J Clin Gastroenterol, 7: 6, 1985 Dec, 477-81

Consecutive patients coming as an emergency with chest pain due to
myocardial ischemia or esophageal disease were interviewed on admission to
the hospital, before they had been fully investigated. Classical features of
angina pectoris were equally common in both groups and "crescendo angina"
was often found in patients with esophageal disease. Features that helped to
distinguish esophageal from cardiac pain were: an atypical response to
exercise, pain that continued as a background ache, retrosternal pain
without lateral radiation, pain that disturbed sleep, and the presence of
certain esophageal symptoms. A positive diagnosis will be made more often in
cases of suspected but unsubstantiated coronary disease by clinicians who
are aware that esophageal pain and angina may be indistinguishable.

Right arm involvement and pain extension can help to differentiate coronary
diseases from chest pain of other origin: a prospective emergency ward study
of 278 consecutive patients admitted for chest pain.
Berger JP, Buclin T, Haller E, Van Melle G, Yersin B
J Intern Med, 227: 3, 1990 Mar, 165-72

In a prospective study of 278 consecutive patients admitted to an emergency
ward for chest pain, the 115 clinical and paraclinical parameters available
at the time of admission were evaluated by computer comparison with the
final diagnoses. The most valuable items for making the diagnosis were
classified according to their sensitivity, specificity and predictive value.
Among the 278 patients, 100 individuals had myocardial infarctions (MI), 47
had unstable angina, 25 had stable angina and 106 patients had a
non-coronary disease. The twelve most sensitive items for distinguishing MI
from other conditions were the following: sudden onset of pain (70%);
duration of more than 60 min (88%); constriction and squeezing (79%);
oppression (75%); prior anginal attacks (61%); sex male (72%); age over 60
years (74%); abnormal heart auscultation (62%); abnormal electrocardiogram
(ECG) (98%); segment (ST) disturbances (86%); increased glucose level (77%);
CKMB fraction greater than 6% of total creatine kinase (CK) level (63%).
Among the twelve most specific items, also with the best positive predictive
value, irradiation in the right arm is of most importance; among the 51
patients with right arm involvement, 48 suffered from a coronary disease and
41 from a myocardial infarction. The largest extension of pain was reported
in the latter group. It is concluded that chest pain with a wide irradiation
involving the right arm strongly suggests that a myocardial infarction is
ongoing.

[Criteria for differential diagnosis in cardial symptoms; left- or
right-sided chest pain?]
Beunderman R, Sramek M, Koster RW, Garssen B, van Dis H
Ned Tijdschr Geneeskd, 134: 46, 1990 Nov 17, 2249-52

We studied the localization of pain in the acute phase of myocardial
infarction in comparison with localization in non-cardiac chest pain.
Myocardial infarction patients could not be differentiated from patients
with non-cardiac chest pain in localization of pain on mid-chest, left side
of the chest and left arm. However, myocardial infarction patients reported
pain on the right side of the chest and in the right arm twice as often as
non-cardiac chest pain patients. Results are similar when patients indicated
the localization of the pain symptoms on attending the Emergency Coronary
Care Unit, or when asked five days later. Pain symptoms on the right side of
the chest and the right arm differentiate better between myocardial
infarction and non-cardiac chest pain than the 'classical' symptom pattern.

Does it help to undiagnose angina?
Dart AM, Davies HA, Griffith T, Henderson AH
Eur Heart J, 4: 7, 1983 Jul, 461-2

We reported recently the results of re-evaluating a series of 64 patients
still experiencing pain originally diagnosed as angina but with normal
coronary arteriograms. A musculoskeletal cause for the chest pain was
established in 38 and an oesophageal cause in 17 of these patients. We here
report these patients' self-assessment of their pain 2 years after this
diagnostic reclassification. It is clear that the effects of a diagnosis of
angina are not easily rescinded even when the non-cardiac cause of the chest
pain is identified.

Failure of information as an intervention to modify clinical management. A
time-series trial in patients with acute chest pain.
Lee TH, Pearson SD, Johnson PA, Garcia TB, Weisberg MC, Guadagnoli E, Cook
EF, Goldman L
Ann Intern Med, 122: 6, 1995 Mar 15, 434-7

OBJECTIVE: To test whether a low-intensity, nonintrusive intervention improved
the efficiency of management of patients with acute chest pain. DESIGN:
Time-series trial with six 14-week cycles, each including a 5-week
intervention period and a 5-week control period separated by 2-week "washout"
periods. SETTING: Urban teaching hospital. PATIENTS: 1921 patients aged 30
years or older with acute chest pain unexplained by local trauma or chest
radiograph. INTERVENTION: Risk estimates and triage recommendations were made
available to physicians at the time of emergency department evaluation and,
for hospitalized patients, on a daily basis before morning rounds. Flowsheets
and stickers, but no direct human contact, were used to transmit this
information. MEASUREMENTS: Rates of admission to the hospital and coronary
care unit, inpatient costs, and lengths of stay. RESULTS: Rates of admission
during intervention and control periods were similar in both the hospital (52%
and 51%, respectively) and the coronary care unit (10% and 10%, respectively).
Total lengths of stay in the hospital were similar (4.9 +/- 5.9 days and 4.9
+/- 5.7 days, respectively), as were average total costs ($7822 +/- $13,217
and $7955 +/- $13,400, respectively). No differences in management were
detected for the subgroup of patients with low clinical risk for acute
myocardial infarction. CONCLUSIONS: The use of information alone--without
direct human contact--did not affect management of patients with acute chest
pain at this hospital. Although this low-intensity intervention might be more
effective for other conditions and in other settings, our data support the use
of other strategies to affect physician decision making.

Lee TH; Cook EF; Weisberg M; Sargent RK; Wilson C; Goldman L
Acute chest pain in the emergency room. Identification and examination of
low-risk patients.
Arch Intern Med, 145: 1, 1985 Jan, 65-9

Clinical and laboratory data from 596 patients who came to an emergency room
complaining of chest pain indicated that no single variable could identify
low-risk patients as well as a normal ECG. A combination of three
variables--sharp or stabbing pain, no history of angina or myocardial
infarction, and pain with pleuritic or positional components or pain that
was reproduced by palpation of the chest wall--defined a very-low-risk group
in which ECGs did not add accuracy to the evaluation and were potentially
misleading; however, only 48 patients (8%) fell into this category. Standard
cardiac enzyme levels were of almost no use as an emergency room indicator
of myocardial infarction. These findings emphasize the difficulty of
identifying patients at low risk for myocardial infarction or unstable
angina in the emergency room without consideration of many factors from the
history, the physical examination, and the ECG.

Millaire A; Ducloux G; Marquand A; Vaksmann G
[Nitroglycerin and angina with angiographically normal coronary vessels.
Clinical effects and effects on esophageal motility]
Arch Mal Coeur Vaiss, 82: 1, 1989 Jan, 63-8

In order to determine whether the presence of a retrosternal pain sensitive
to nitroglycerin is predictive of the finding of esophageal dyskinesia in
patients with normal coronary angiography and negative methylergonovine
test, we administered 0.8 mg of a nitroglycerin spray during esophageal
manometry and after a methylergonovine or edrophonium provocation test. The
effects of nitroglycerin on esophageal motility were recorded and compared
with clinical data. Forty patients (21 men, 19 women, mean age 54 +/- 8
years) entered the study. In 22 of them (55 p. 100) the retrosternal pain
was relieved by nitroglycerin within less than 5 minutes; the provocation
test was positive in 10 cases (25 p. 100). In all patients nitroglycerin
produced a highly significant decrease in the duration and amplitude of
esophageal contractions. Among the 10 patients with esophageal dyskinesia,
the duration of contractions was significantly more reduced (p less than
0.005) in those with nitroglycerin-sensitive pain (6 patients) than in those
with nitroglycerin-resistant pain. These 6 patients, therefore, could be
regarded clinically and manometrically as "responders" to nitroglycerin. Two
of them had gastro-esophageal reflux. In contrast, among patients without
induced esophageal dyskinesia the effects of nitroglycerin on manometry were
the same irrespective of whether or not pain was usually relieved by
nitroglycerin. The fact that pain was nitroglycerin-sensitive had no
predictive value concerning the finding of esophageal dyskinesia by the
provocation test (non-significant X2 test). We conclude that the clinical
and manometric effects of nitroglycerin were concordant only in patients
with induced esophageal dyskinesia; patients who responded to nitroglycerin
could have a gastro-esophageal reflux.(ABSTRACT TRUNCATED AT 250 WORDS)

Chauhan A; Petch MC; Schofield PM
Effect of oesophageal acid insti
llation on coronary blood flow.
Lancet, 341: 8856, 1993 May 22, 1309-10

To assess whether gastrointestinal factors can cause chest pain ("linked
angina"), we studied the effect of oesophageal stimulation with acid on
coronary blood flow in 20 syndrome X patients. Coronary blood flow velocity
(CBFV) was measured with an intracoronary doppler catheter positioned in the
proximal left anterior descending coronary artery. Acid stimulation produced
typical anginal pain in 11 patients. Mean CBFV was significantly reduced
from 7.3 (SD 4.0) to 4.4 (2.8) cm/s. Gastro-oesophageal reflux leading to
reduced coronary blood flow may be a mechanism to explain linked angina.

Mellow MH; Simpson AG; Watt L; Schoolmeester L; Haye OL
Esophageal acid perfusion in coronary artery disease. Induction of
myocardial ischemia.
Gastroenterology, 85: 2, 1983 Aug, 306-12

Although coronary artery disease and gastroesophageal reflux disease are
common conditions which, therefore, may coexist, it is unknown whether or
not the presence of one affects the other. We performed esophageal acid
perfusion tests, with concurrent blood pressure, heart rate, and 12-lead
electrocardiographic monitoring, in 37 patients, 25 with angiographically
documented coronary disease and 12 with normal coronary arteries.
Rate-pressure product, an index of myocardial work load, was calculated. In
patients with coronary disease who developed chest pain during acid
perfusion, rate-pressure product increased from 10.0 +/- 1.0 x 10(3) (mean
+/- SEM) basally to 15.2 +/- 1.5 x 10(3) (p less than 0.001), and 3 of 9
patients showed concomitant electrocardiogram evidence of myocardial
ischemia. In addition, in coronary disease, 64% of patients with infrequent
or absent reflux symptoms by history had positive acid perfusion tests, and
56% of patients with coronary disease who developed pain during esophageal
acid perfusion could not distinguish that pain from their usual angina. We
conclude that in coronary disease, acid perfusion (and, presumably,
gastroesophageal reflux) resulting in chest pain causes rate-pressure
product elevation and can induce myocardial ischemia. The presence of
esophageal acid sensitivity is not accurately predicted by clinical history
in coronary disease, and pain of esophageal origin is often confused with
angina.

Lam HG; Dekker W; Kan G; van Berg Henegouwen GP; Smout AJ
Esophageal dysfunction as a cause of angina pectoris ("linked angina"): does
it exist?
Am J Med, 96: 4, 1994 Apr, 359-64

PURPOSE: The differentiation between cardiac and esophageal causes of
retrosternal chest pain is notoriously difficult. Theoretically, cardiac and
esophageal causes may coexist. It has also been reported that gastroesophageal
reflux and esophageal motor abnormalities may elicit myocardial ischemia and
chest pain, a phenomenon called linked angina pectoris. The aim of this study
was to assess the incidence of esophageal abnormalities as a cause of
retrosternal chest pain in patients with previously documented coronary artery
disease.
PATIENTS AND METHODS: Thirty consecutive patients were studied, all of whom
had undergone coronary arteriography. The patients were studied after they
were admitted to the coronary care unit with an attack of typical chest pain.
On electrocardiograms (ECGs) taken during pain, 15 patients (group I) had new
signs of ischemia; the other 15 patients (group II) did not. In none of the
patients were cardiac enzymes elevated. As soon as possible, but within 2
hours after admission, combined 24-hour recording of esophageal pressure and
pH was performed. During chest pain, 12-lead ECG recording was carried out.
RESULTS: In group I, all 15 patients experienced one or more pain episodes
during admission, 25 of which were associated with ischemic
electrocardiographic changes. The other two episodes were reflux-related. Only
one of the 25 ischemia-associated pain episodes was also reflux-related, ie,
it was preceded by a reflux episode. In group II, 19 chest pain episodes
occurred in 11 patients. None of these was associated with
electrocardiographic changes, but 8 were associated with reflux (42%) and 8
with abnormal esophageal motility (42%).
CONCLUSION: Linked angina is a rare phenomenon.

Gignoux C; Bost R; Hostein J; Turberg Y; Denis P; Cohard M; Wolf JE; Fournet J
Role of upper esophageal reflex and belch reflex dysfunctions in noncardiac
chest pain.
Dig Dis Sci, 38: 10, 1993 Oct, 1909-14

Fifty-four patients examined for noncardiac chest pain (NCCP), showing no
esophageal motor disorder or gastroesophageal reflux disease compatible with
NCCP, were subjected to an intraesophageal balloon distension test and a study
of the belching reflex provoked by intraesophageal air injection. Thirty-three
control subjects were also studied, allowing us to define high-threshold
belchers (group I) as those who belched during two of three 40-ml distensions
and low-threshold belchers (group II) as those who did not. The balloon
distension test induced NCCP in 64% of the patients in group I, and in 14% of
the patients in group II (P < 0.01). High-threshold belching was a factor
favoring the positivity of the balloon distension test. This result supports
the hypothesis that esophageal distension by air due to a belching disorder
may be the mechanism responsible for NCCP in some patients with an abnormal
sensitivity to balloon distension.

Gignoux C; Bost R; Hostein J; Turberg Y; Denis P; Cohard M; Wolf JE; Fournet J
Role of upper esophageal reflex and belch reflex dysfunctions in noncardiac
chest pain.
Dig Dis Sci, 38: 10, 1993 Oct, 1909-14

Fifty-four patients examined for noncardiac chest pain (NCCP), showing no
esophageal motor disorder or gastroesophageal reflux disease compatible with
NCCP, were subjected to an intraesophageal balloon distension test and a study
of the belching reflex provoked by intraesophageal air injection. Thirty-three
control subjects were also studied, allowing us to define high-threshold
belchers (group I) as those who belched during two of three 40-ml distensions
and low-threshold belchers (group II) as those who did not. The balloon
distension test induced NCCP in 64% of the patients in group I, and in 14% of
the patients in group II (P < 0.01). High-threshold belching was a factor
favoring the positivity of the balloon distension test. This result supports
the hypothesis that esophageal distension by air due to a belching disorder
may be the mechanism responsible for NCCP in some patients with an abnormal
sensitivity to balloon distension.

Kahrilas PJ; Dodds WJ; Hogan WJ
Dysfunction of the belch reflex. A cause of incapacitating chest pain.
Gastroenterology, 93: 4, 1987 Oct, 818-22

We report a 25-yr-old woman who suffered incapacitating chest pain caused by
upper esophageal sphincter (UES) dysfunction. She presented with a long
history of severe episodic chest pain associated with gurgling noises in her
chest and was unable to belch despite feeling a need to do so during pain
episodes. Fluoroscopic and manometric studies confirmed that the patient's
chest pain and gurgling noise were associated with dysfunction of the belch
reflex. Although reflux of gas from the stomach into the esophageal body
occurred normally, the extreme esophageal distention resulting from the gas
reflux failed to trigger UES relaxation. Consequently, there was no venting
of gas across the UES. The gurgling noise was caused by the gastroesophageal
reflux of gas and the pain was associated with profound esophageal
distention. A manometric study of the UES revealed absent or incomplete UES
relaxation in response to abrupt esophageal distention by gastroesophageal
gas reflux, so that the nadir of UES pressure always exceeded esophageal
body pressure. The distended esophagus was repeatedly cleared by secondary
peristalsis. To our knowledge this is the first description of chest pain
caused by dysfunction of the belch reflex. We speculate that the mechanism
described in this patient may account for a subgroup of patients with "chest
pain of esophageal origin."

Gnecchi Ruscone T, Guzzetti S, Lombardi F, Lombardi R
Lack of association between prodromes nausea and vomiting, and specific
electrocardiographic patterns of acute myocardial infarction.
Int J Cardiol 1986 Apr;11(1):17-23

We conducted an observational study on 164 patients consecutively admitted to
our coronary care unit in order to evaluate the predictive role of cardiac
prodromes nausea and vomiting, in distinguishing a particular
electrocardiographic pattern (Q wave versus non-Q wave and localisation) of an
acute myocardial infarction. Patients with the prodromes made up 47.0% of all
Q wave myocardial infarction and 59.4% in those without Q wave myocardial
infarction. Furthermore, patients had nausea and vomiting in 25.0% of all Q
wave myocardial infarction and in 31.2% of all non-Q wave infarction. No
significant differences were found in the patients who experienced nausea and
vomiting in the localisation (anterior versus inferior) of myocardial
infarction. Our findings indicate that the cardiac prodromes of nausea and
vomiting do not play any particular role in predicting a specific
electrocardiographic pattern of acute myocardial infarction.

Jayes RL Jr, Beshansky JR, D'Agostino-RB, Selker-HP.
Do patients' coronary risk factor reports predict acute cardiac ischemia
in the emergency department? A multicenter study.
Department of Medicine, New England Medical Center, Boston, MA 02111.

The objective of the present study was to determine whether the
presence of the classical coronary risk factors increases the likelihood of
acute cardiac ischemia beyond that expected from clinical presentation and
electrocardiogram. Clinical data and reports of classical coronary risk
factors were collected prospectively from 1743 patients without clinically
obvious coronary disease. Patients were selected from 5773 emergency
department patients at 6 hospitals who presented with symptoms suggesting
acute ischemia. We used logistic regression to determine the relative risk
of each risk factor report for acute ischemia. In women, the presence of
classical risk factor reports does not increase the risk of acute ischemia.
In men, only diabetes and family history of myocardial infarction
significantly increase the risk (p less than 0.05). The relative risks are
2.4 and 2.1, respectively, and are small compared to those conferred by
chest pain (12.1), an abnormal ST segment (8.7), or an abnormal T wave
(5.3). For a patient presenting to the emergency department, the classical
coronary risk factors convey minimal risk for acute cardiac ischemia,
especially when compared to the overwhelming importance of the chief
complaint and the ECG.

Murata GH
Evaluating chest pain in the emergency department
West J Med 1993; 159:61-8

Chest pain is one of the most difficult diagnostic problems for physicians
working in an emergency department. In this setting, more malpractice dollars
are awarded for missed myocardial infarction than for any other physician
error. This problem usually occurs when the patient has atypical symptoms, the
physician is inexperienced, or the diagnosis is not considered. The clinical
manifestations of myocardial infarction vary greatly, and patients with
"atypical" presentations have a poorer prognosis than those with classic
symptoms. Although no feature of a patient's history excludes infarction with
certainty, pain that is sharp, positional, pleuritic, or reproduced by
palpation indicates a lower probability of acute ischemic heart disease. New
immunochemical methods and serial sampling strategies have increased the
sensitivity of creatine kinase-MB as an indicator for the disorder. Recent
investigations have also established the prognostic value of the initial
electrocardiogram. These methods allow emergency physicians to assess the risk
of complications and to perform triage when there is a shortage of beds in the
coronary care unit. Emergency physicians must also consider other diseases for
which coronary care might be beneficial.

Ting HH, Lee TH, Soukup JR, et al.
Impact of physician experience on triage of emergency room patients with acute
chest pain at three teaching hospitals
Am J Med 1991; 91:401-8

PURPOSE: To determine whether the experience of the physician (as measured by
postgraduate training level or time during the academic year) who performs the
initial evaluation affects the triage of patients with acute chest pain.
PATIENTS AND METHODS: Prospective data on the presenting clinical features,
initial triage, final diagnosis, and complications were collected for 7,857
patients who presented to the emergency rooms of three teaching hospitals,
including 1,118 (14%) with acute myocardial infarction (AMI), 2,477 (32%) with
acute ischemic heart disease (AIHD) (i.e., AMI or unstable angina), and 335
(4%) with major complications. The experience of the evaluating physicians,
who were in their first three postgraduate years in 93% of cases, was measured
in three ways: (1) postgraduate training level, (2) month during the academic
year, and (3) number of patients with acute chest pain previously evaluated.
Multivariate logistic regression analyses that adjusted for hospital site and
20 clinical variables estimated the odds ratios for admission to the coronary
care unit (CCU) and hospital associated with each incremental increase in
physician experience. RESULTS: With more experience (as measured by
postgraduate training level or time during the academic year), the sensitivity
of physicians for admitting patients with AMI, AIHD, or major complications to
the hospital increased. For example, each incremental increase in postgraduate
training level carried a 1.4 increase in the adjusted odds ratio for admission
of a patient with AIHD to the hospital (p less than 0.05), corresponding to an
increase in the probability of admission from 93% to 97%. However, increasing
physician experience was also associated with an elevated false-positive rate
in admitting patients without these diagnoses to the CCU and hospital. Thus,
each incremental increase in postgraduate training level carried a 1.2
increase in the adjusted odds ratio for admission of a patient without AIHD to
the CCU and hospital (p less than 0.005), corresponding to an increase in the
probability of admission from 34% to 47%. By receiver operating characteristic
curve (ROC) regression analyses, these changes in triage patterns were
consistent with movement along a single ROC curve, rather than a shift to a
new or better ROC curve. CONCLUSIONS: As the experience of the physician who
performed the initial evaluation increased, there was a lower threshold for
admitting all patients with and without AMI, AIHD, or major complications to
the CCU and hospital without a detectable improvement in diagnostic accuracy.

Johnson PA, Lee TH, Cook EF, Rouan GW, Goldman L
Effect of race on the presentation and management of patients with acute chest
pain [see comments]
Ann Intern Med 1993; 118:593-601

OBJECTIVE: To compare racial differences in clinical presentation, natural
history, and access to medical care and procedures among emergency-department
patients with acute chest pain. DESIGN: Prospective follow-up study of
consecutive patients coming to the emergency department because of acute chest
pain. SETTING: Two university medical centers. PATIENTS: A total of 3031
patients who were 30 years or older and who came to the emergency department
with acute chest pain from 1984 to 1986. MAIN RESULTS: African-Americans
tended to have slightly, but not always significantly, lower rates of acute
myocardial infarction, acute ischemic heart disease, and major complications,
after adjusting for presenting symptoms and signs; the adjusted odds ratios
for African-Americans were as follows: 0.77 (95% CI, 0.54 to 1.1) for acute
myocardial infarction, 0.75 (CI, 0.59 to 0.95) for ischemic heart disease, and
0.79 (CI, 0.45 to 1.4) for death or major complications. Clinical factors
classically associated with acute myocardial infarction were equally
predictive in African-Americans and whites. After adjustments were made for
multiple clinical factors, a lower proportion of African-Americans were
admitted to the hospital (odds ratio, 0.69; CI, 0.56 to 0.84), and, once
admitted, were somewhat less likely to be triaged to the coronary care unit
(odds ratio, 0.81; CI, 0.65 to 1.0). In adjusted analyses, African-Americans
were as likely to undergo cardiac catheterization as whites (odds ratio, 0.86;
CI, 0.64 to 1.2) but were less likely to undergo coronary artery bypass
procedures once severity of coronary disease was included in the analysis
(odds ratio, 0.24; CI, 0.08 to 0.71). CONCLUSION: African-Americans and whites
had a similar presentation and natural history of acute myocardial infarction
and, after adjusting for probability of clinical events, similar access to
most medical care and cardiac procedures. However, the rate of coronary artery
bypass procedures was much lower among African-Americans than among whites.
Reasons for this difference should be studied.

Lee TH, Cook EF, Weisberg MC, et al.
Impact of the availability of a prior electrocardiogram on the triage of the
patient with acute chest pain [see comments]
J Gen Intern Med 1990; 5:381-8

STUDY OBJECTIVE: To determine whether information from a prior
electrocardiogram (ECG) improves diagnostic accuracy in the emergency
department (ED) evaluation of patients with acute chest pain. DESIGN: Analysis
of prospectively collected data from a cohort study. SETTING: Emergency
departments of four community and three university hospitals. PATIENTS: 5,673
patients aged greater than or equal to 30 years who presented to the EDs of
participating hospitals for evaluation of acute chest pain, including 772
(14%) with acute myocardial infarction (AMI). MEASUREMENTS AND MAIN RESULTS:
After adjusting for clinical characteristics, no significant difference was
found in the sensitivities of admission to the hospital or to the coronary
care unit (CCU) between AMI patients with and without prior ECGs available for
review. However, non-AMI patients with prior ECGs available for review were
more likely to avoid CCU admission than were non-AMI patients without prior
ECGs. This improvement in specificity was most marked in the 2,024 patients
whose current ED ECGs had changes consistent with ischemia or infarction: when
a prior ECG was available, non-AMI patients were more than twice as likely to
be discharged (26% vs. 12%) and about 1.5 times as likely to avoid CCU
admission (39% vs. 27%) (both p less than 0.0001). Admission rates of AMI
patients with and without prior ECGs were similar. CONCLUSION: When the
current ECG is consistent with ischemia or infarction, the availability of a
prior ECG for comparison to determine whether the ECG changes are old or new
improves diagnostic accuracy and triage decisions by reducing the admission of
patients without AMI or acute ischemic heart disease (increased specificity)
without reducing the admission of patients with these diagnoses (unchanged
sensitivity).

Johnson PA, Goldman L, Orav EJ, et al.
Gender differences in the management of acute chest pain. Support for the
"Yentl syndrome"
J Gen Intern Med 1996; 11:209-17

OBJECTIVE: To determine whether evaluation and management of males and females
differ after presentation to the emergency department with acute chest pain.
DESIGN: Prospective cohort study with follow-up at 1 month. SETTING: Urban
teaching hospital. PATIENTS: The study population included 1,411 patients who
were 30 years of age or older who visited the emergency department with acute
chest pain from October 1990 through May 1992. These 1,411 patients represent
69% of the 2,056 patients approached for consent. The utilization of exercise
stress testing as outpatients was measured for a subset of 954 patients who
were interviewed at 1 month after their presentation. MEASUREMENTS/MAIN
RESULTS: After controlling for clinical and nonclinical predictors, women were
less likely to be admitted to the hospital (adjusted odds ratio [OR] 0.68; 95%
confidence interval [CI] 0.47, 0.99). Among the 954 patients with 1-month
follow-up, women were less likely than men to undergo an exercise stress test
during the first month after presentation, with borderline statistical
significance after adjusting for the interaction between gender and admission
to the hospital (adjusted OR 0.30; 95% CI 0.09, 1.0). Among the patients who
were admitted to the hospital, women were as likely as men to undergo exercise
stress testing (adjusted OR 0.81; 95% CI 0.57, 1.2) but were less likely to
undergo cardiac catheterization (adjusted OR 0.44; 95% CI 0.25, 0.80).
CONCLUSIONS: Gender-based differences in management may occur at several
stages in the evaluation of patients with acute chest pain. Observed
differences in use of invasive procedures between men and women may be due in
part to lower rates of exercise test use and admission to the hospital for
evaluation of acute chest pain.

Pearson SD, Goldman L, Orav EJ, et al.
Triage decisions for emergency department patients with chest pain: do
physicians' risk attitudes make the difference?
J Gen Intern Med 1995; 10:557-64

OBJECTIVE: To determine whether physicians' risk attitudes correlate with
their triage decisions for emergency department patients with acute chest
pain. DESIGN: Cohort. SETTING: The emergency department of a university
teaching hospital. PATIENTS: Patients presenting to the emergency department
with a chief complaint of acute chest pain. PHYSICIANS: All physicians who
were primarily responsible for the emergency department triage of at least one
patient with acute chest pain from July 1990 to July 1991. METHODS: The
physicians' risk attitudes were assessed by two methods: 1) a new,
six-question risk-taking scale adapted from the Jackson Personality Index
(JPI), and 2) the Stress from Uncertainty Scale (SUS). RESULTS: The physicians
who had high risk-taking scores ("risk seekers") admitted only 31% of the
patients they evaluated, compared with admission rates of 44% for the medium
scores and 53% for the physicians who had low risk-taking scores ("risk
avoiders"), p < 0.001. After adjustment for clinical factors, the patients
triaged by the risk-seeking physicians had half the odds of admission [odds
ratio (OR) 0.51, 95% confidence interval (95% CI) 0.27 to 0.97], and the
patients triaged by the risk-avoiding physicians had nearly twice the odds of
admission (OR 1.83, 95% CI 1.10 to 3.03) of the patients triaged by the
medium-risk scoring physicians. The SUS did not correlate significantly with
admission rates. Of the 92 patients released home by the risk-seeking
physicians, 91 (99%) were known to be alive four to six weeks afterwards and
one was lost to follow-up; among the 66 patients released by the risk-avoiding
physicians, 64 (97%) were known to be alive at four to six weeks, one was lost
to follow-up, and one died of ischemic heart disease during a subsequent
hospitalization (p = NS). CONCLUSIONS: The physicians' risk attitudes as
measured by a brief risk-taking scale correlated significantly with their
rates of admission for emergency department patients with acute chest pain.
These data do not suggest that the risk-seeking physicians achieved lower
admission rates by releasing more patients who needed to be in the hospital,
but an adequate evaluation of the appropriateness of triage decisions of
risk-seeking and risk-avoiding physicians will require further study.

Pearson SD, Goldman L, Garcia TB, Cook EF, Lee TH
Physician response to a prediction rule for the triage of emergency department
patients with chest pain
J Gen Intern Med 1994; 9:241-7

OBJECTIVE: To determine the response of physicians to a noncoercive prediction
rule for the triage of emergency department patients with chest pain. DESIGN:
Prospective time-series intervention study. SETTING: A university hospital
emergency department. PARTICIPANTS/PATIENTS: 68 physicians, all of whom were
responsible for the triage of at least one of 252 patients presenting to the
emergency department with a chief complaint of acute chest pain. INTERVENTION:
A previously validated algorithmic prediction rule that was attached to the
back of patient data forms in the emergency department. MEASUREMENTS:
Patients' clinical data were recorded by the examining physician in the
emergency department or by a research nurse blinded to patient outcome. The
physicians recorded their own estimates of the risk of acute myocardial
infarction and their reactions to the prediction rule in a self-administered
questionnaire completed at the time of triage. MAIN RESULTS AND CONCLUSIONS:
The physicians reported that they looked at the prediction rule during the
triage of 115 (46%) of the 252 patients. The likelihood of using the
prediction rule decreased significantly with increasing level of physician
training. The most common reasons given for disregarding the prediction rule
were confidence in unaided decision making and lack of time. The physicians
reported that of the 115 cases for which the prediction rule was used, only
one triage decision (1%) was changed by it. Future research should explore how
prediction rules can be designed and implemented to surmount the barriers
highlighted by these data.

Pearson SD, Lee TH, Lindsey E, et al.
The impact of membership in a health maintenance organization on hospital
admission rates for acute chest pain
Health Serv Res 1994; 29:59-74

OBJECTIVE. We evaluate the impact of membership in a staff-model health
maintenance organization (HMO) on hospital admission rates for patients
presenting to an emergency department with acute chest pain. DATA SOURCES AND
STUDY SETTING. Primary prospective data were gathered from all 3,006 patients
presenting with a chief complaint of chest pain to the emergency department
(ED) of a university teaching hospital from October 1987 to November 1989.
STUDY DESIGN. Prospective cohort analysis used clinical data to stratify
patients into groups at high (> or = 25%), medium (8-24%), and low risk (< or
= 7%) of acute myocardial infarction (AMI). Insurance status was determined as
either HMO, Medicare, commercial, Medicaid, or self-pay. Triage decisions were
recorded, and patient outcomes of AMI and other final diagnoses were
determined for all patients. DATA COLLECTION METHODS. Clinical data were
recorded by the physicians in the ED as part of a detailed protocol. Insurance
data were recorded separately by the ED staff as part of the hospital
administrative database. Patient outcomes were recorded daily by research
nurses for hospitalized patients; for patients who were discharged from the
ED, telephone or physician follow-up was accomplished within seven days after
discharge. PRINCIPAL FINDINGS. HMO patients were more likely to be admitted to
the hospital than patients in other insurance groups in both the medium- and
low-risk patient categories. Within the low-risk category, after controlling
for clinical differences in a multiple logistic model, HMO membership retained
an independent positive association with hospital admission compared to all
other insurance groups except Medicaid. CONCLUSIONS. For patients with acute
chest pain who were at medium and low risk of acute myocardial infarction, HMO
membership was associated with higher rates of hospital admission. These
findings suggest that organizational factors beyond financial incentives may
exercise an important influence on hospitalization rates for HMO patients.

Krumholz HM, Friesinger GC, Cook EF, et al.
Relationship of age with eligibility for thrombolytic therapy and mortality
among patients with suspected acute myocardial infarction
J Am Geriatr Soc 1994; 42:127-31

OBJECTIVE: To determine the relationship of age and the percentage of patients
presenting to the emergency department with myocardial infarction who meet
conventional electrocardiographic and time-to-presentation criteria for
thrombolytic therapy. DESIGN: Prospective cohort study. SETTING: Emergency
departments of three university hospitals and four community hospitals.
PATIENTS: Patients enrolled in the Multicenter Chest Pain Study, an
investigation of patients aged 30 years or older presenting to the emergency
department with the chief complaint of anterior, precordial, or left lateral
chest pain unexplained by obvious local trauma or abnormalities on the chest
radiograph. INTERVENTIONS: None. MEASUREMENTS: The frequency of patients who
presented with conventional electrocardiographic and time-to-presentation
criteria for thrombolysis. MAIN RESULTS: Of a total of 12,140 patients who
were enrolled in the Multicenter Chest Pain Study, 10,850 had information
about their electrocardiogram and their time-to-presentation. Acute myocardial
infarction occurred in 1,584 patients, 746 of whom were over age 65. Among
patients presenting to the emergency department with acute myocardial
infarction, the proportion who arrived within 6 hours of the onset of pain and
had ST-segment elevation or pathologic Q-waves not known to be old decreased
significantly with increasing age, from 34% in patients under 65 years to 18%
for those 75 years and older. In addition, comorbidities that would have
contraindicated thrombolytic therapy were present in an additional 12% of
myocardial infarction patients who were older than 65 years. CONCLUSION:
Although other analyses have shown that thrombolytic therapy is cost-effective
for eligible elderly patients with acute myocardial infarction, only a small
percentage of very elderly patients who present to the emergency department
with acute myocardial infarctions meet current eligibility criteria to receive
it, so thrombolysis is unlikely to narrow the difference in mortality rates
for young as compared with elderly patients with acute infarctions.

Rouan GW, Lee TH, Cook EF, et al.
Clinical characteristics and outcome of acute myocardial infarction in
patients with initially normal or nonspecific electrocardiograms (a report
from the Multicenter Chest Pain Study)
Am J Cardiol 1989; 64:1087-92

To determine the prevalence and characteristics of acute myocardial infarction
(AMI) patients who present to emergency departments with normal or nonspecific
electrocardiograms (ECGs), data were analyzed from 7,115 consecutive patients
in the Multicenter Chest Pain Study. AMI patients with normal or nonspecific
initial ECGs (n = 107) were less likely to have a past history of coronary
artery disease or to be diaphoretic on presentation (p less than 0.01) than
AMI patients with initial ECGs highly suggestive of AMI (n = 811). The overall
probability of AMI among patients with chest pain and initially normal or
nonspecific ECGs was 3%, but ranged from less than 1 to 17% depending on the
patient's age and sex and whether the patient had pressure-type pain or pain
radiating to the shoulder, neck or arms. Among initially admitted patients,
the time elapsed between onset of pain and presentation was similar in both
groups. However, the time between onset of pain and definitive diagnosis of
AMI by enzymes or clinical course was longer in patients with initially normal
or nonspecific electrocardiograms (8.3 vs 7.5 hours, p less than 0.05), their
peak creatine kinase levels were lower (mean 643 vs 1,032 mg/dl, p less than
0.001) and their mortality was slightly lower (6 vs 12%, p = 0.10). These
findings suggest that AMI patients with initially normal or nonspecific ECGs
may have a less severe short-term clinical outcome.

Cunningham MA, Lee TH, Cook EF, et al.
The effect of gender on the probability of myocardial infarction among
emergency department patients with acute chest pain: a report from the
Multicenter Chest Pain Study Group
J Gen Intern Med 1989; 4:392-8

OBJECTIVE: To identify differences in the incidences of myocardial infarction
in women and men with chest pain. DESIGN: Prospective multicenter cohort
study. SETTING: Emergency rooms of three university and four community
hospitals. PATIENTS: 7,734 emergency room patients with acute chest pain.
MEASUREMENTS AND MAIN RESULTS: Myocardial infarction was diagnosed in 10% of
the 3,896 women, compared with 19% of the 3,838 men, yielding an age-adjusted
relative risk of myocardial infarction for women of 0.54 (95% confidence
interval 0.48, 0.60). Physicians were equally adept at admitting women and men
with myocardial infarctions, but men without myocardial infarction or unstable
angina were significantly more likely to be admitted than were women without
these diagnoses. Most clinical and electrocardiographic features indicating a
risk of myocardial infarction were present in both women and men, but several
high-risk features were less commonly present in women. After adjusting for
the other factors that correlate with each patient's probability of having
acute myocardial infarction, the relative risk of myocardial infarction was
the same in women as men when the emergency department electrocardiogram
showed the classic changes associated with acute myocardial infarction, but
the risk was 40% lower in women when such electrocardiographic changes were
not present. CONCLUSIONS: Clinical features that predict myocardial infarction
in men predict myocardial infarction in women to a similar extent. However,
female gender is associated with about a 40% lower rate of myocardial
infarction except when classic electrocardiographic evidence is present on the
emergency department electrocardiogram.

Lee TH, Weisberg MC, Brand DA, Rouan GW, Goldman L
Candidates for thrombolysis among emergency room patients with acute chest
pain. Potential true- and false-positive rates [see comments]
Ann Intern Med 1989; 110:957-62

STUDY OBJECTIVE: To assess the potential clinical impact of thrombolytic
therapy for acute myocardial infarction by determining true-positive and
false-positive rates of criteria for eligibility among emergency room patients
with acute chest pain. DESIGN: Prospective multicenter cohort study. SETTING:
Emergency rooms of three university and four community hospitals. PATIENTS:
Emergency room patients (7734) with acute chest pain. MEASUREMENTS AND MAIN
RESULTS: Only 261 (23%) of 1118 patients with acute myocardial infarctions
were 75 years of age or younger, presented within 4 hours of the onset of
pain, and had emergency room electrocardiograms showing probable acute
myocardial infarction: 60 (0.9%) of the 6616 patients without infarction also
met these criteria (positive predictive value, 261/321 = 81%; CI, 77% to 86%).
The positive predictive value could increase to about 88% (CI, 82% to 93%) if
eligibility were based on the official hospital electrocardiogram reading.
CONCLUSIONS: Because experience from published studies suggests that about one
third of patients who meet these three eligibility criteria have other
contraindications to thrombolysis, we estimate that about 15% of patients with
acute myocardial infarction would meet the criteria for eligibility for
thrombolysis that have been used in clinical trials at the time of emergency
room presentation. Further, for every eight patients with true-positive
results who are treated, one to two patients with false-positive results may
also be treated if decisions are based on the interpretation of a single
electrocardiogram.

Goldman L, Weinberg M, Weisberg M, et al.
A computer-derived protocol to aid in the diagnosis of emergency room patients
with acute chest pain
N Engl J Med 1982; 307:588-96

To determine whether data available to physicians in the emergency room can
accurately identify which patients with acute chest pain are having myocardial
infarctions, we analyzed 482 patients at one hospital. Using recursive
partitioning analysis, we constructed a decision protocol in the format of a
simple flow chart to identify infarction on the basis of nine clinical
factors. In prospective testing on 468 other patients at a second hospital,
the protocol performed as well as the physicians. Moreover, an integration of
the protocol with the physicians' judgments resulted in a classification
system that preserved sensitivity for detecting infarctions, significantly
improved the specificity (from 67 per cent to 77 per cent, P less than 0.01)
and positive predictive value (from 34 per cent to 42 per cent, P = 0.016) of
admission to an intensive-care area. The protocol identified a subgroup of 107
patients among whom only 5 per cent had infarctions and for whom admission to
non-intensive-care areas might be appropriate. This decision protocol warrants
further wide-scale prospective testing but is not ready for routine clinical
use.

Goldman L, Cook EF, Brand DA, et al.
A computer protocol to predict myocardial infarction in emergency department
patients with chest pain
N Engl J Med 1988; 318:797-803

To achieve more appropriate triage to the coronary care unit of patients
presenting with acute chest pain, we used clinical data on 1379 patients at
two hospitals to construct a simple computer protocol to predict the presence
of myocardial infarction. When we tested this protocol prospectively in 4770
patients at two university hospitals and four community hospitals, the
computer-derived protocol had a significantly higher specificity (74 vs. 71
percent) in predicting the absence of infarction than physicians deciding
whether to admit patients to the coronary care unit, and it had a similar
sensitivity in detecting the presence of infarction (88.0 vs. 87.8 percent).
Decisions based solely on the computer protocol would have reduced the
admission of patients without infarction to the coronary care unit by 11.5
percent without adversely affecting the admission of patients in whom emergent
complications developed that required intensive care. Although this protocol
should not be used to override careful clinical judgment in individual cases,
the computer protocol for the most part yields accurate estimates of the
probability of myocardial infarction. Decisions about admission to the
coronary care unit based on the protocol would have been as effective as those
actually made by the unaided physicians who cared for the patients, and less
costly. Whether physicians who are aided by the protocol perform better than
unaided physicians cannot be determined without further study.