Chest Pain Evaluation
Introduction
Complaints of pain localized to the chest pose a diagnostic challenge. Many
individuals with chest pain have a benign course due to a self-limiting musculoskeletal
process. However, appropriate and dedicated attention must be paid to each individual to
approach the most likely clinical etiology. The young active duty population is not immune
to atherosclerotic coronary artery disease causing angina pectoris or myocardial
infarction.
Sources of Chest Pain
Chest pain may be arbitrarily categorized as arising from:
- The heart, great vessels, and pericardium.
- The gastrointestinal tract.
- The lungs and pleura.
- The chest wall.
Diagnostic Challenge
Identification of ischemic chest pain requires a high index of suspicion. When the
diagnosis of myocardial infarction is overlooked and patients are sent home, the mortality
during the next 72 hours is about 25 percent in comparison with about 6 percent for
patients with infarction who are hospitalized. We are, therefore, liberal in admissions
for evaluation of coronary artery disease. The incidence of acute myocardial infarction in
patients hospitalized with acute chest pain is between 25 to 30 percent. Still,
identification of those individuals with unstable angina or an acute myocardial infarction
may pose considerable uncertainty. Despite conservative admission rates clinicians
misdiagnose approximately 5-10 percent of patients with myocardial infarction.
History
The history dominates decision making. Elements of the history important in
discriminating cardiac from noncardiac chest pain are quality, severity, duration and
frequency. Knowledge of exacerbating features and maneuvers that tend to ameliorate the
discomfort provide insight. Cardiac risk factors should not overly influence clinical
thinking. The presence of risk factors simply implies that an individual is more likely to
develop overt signs of atherosclerotic heart disease in the years ahead than a person who
does not have such markers. They are supportive of an appropriate clinical history, but by
no means provide exclusionary criteria.
Pain Character
Chest pain of coronary ischemic origin is classically a dull heavy pressure. Still,
an endless list of adjectives has been used to describe the unpleasant feeling of angina
pectoris. This discomfort may be confined to the chest or there may be associated aching
in one or both arms, more often the left. Neck or mandibular pain or aching confined to
the shoulder, wrist, elbow, or forearm may manifest solely or in concert with typical
chest pressure. Myocardial ischemia is seldom the cause of discomfort in an area that is
no larger than the tip of a finger. Suspect also is the radiation of pain to the digits.
Brief bursts of pain lasting seconds or discomfort that persists continuously for days at
a time is not due to myocardial ischemia. Effort or emotional stress commonly provokes
angina. However, angina may occur at rest if perfusion is significantly compromised. Pain
subsides within 1 to 5 minutes if the evoking activity is discontinued. Nitroglycerin
hastens this relief.
Role of the
Electrocardiogram (ECG)
The 12-lead ECG has limited value in excluding the presence of coronary artery
disease. Excluding the diagnosis of angina pectoris or myocardial infarction because of a
normal ECG is as great an error as inferring a diagnosis of atherosclerotic coronary
artery disease from the incorrect interpretation of nonspecific electrocardiographic
abnormalities
Cocaine Use and Chest Pain
Cocaine use is temporally related to the development of acute chest pain and has
been associated with acute myocardial infarction. Cocaine causes decreased coronary blood
flow through vasoconstriction. There is speculation that rhabdomyolysis, a known
complication of cocaine use, may effect thoracic musculature providing another mechanism
for the chest pain. All patients presenting for evaluation should be questioned about
cocaine use. A urine drug screen is advisable.
Cardiovascular Origin
Aortic dissection is a diagnosis often overlooked when evaluating chest pain.
Although uncommon, its consequences are devastating. Pain is typically abrupt and sharp in
its onset, with radiation to the infrascapular region. A murmur of aortic insufficiency
may be appreciated. The ECG shows no sign of acute myocardial infarction unless dissection
involves the coronary ostia. Hypertension may be an antecedent risk. Recognizing this
disorder in the differential improves the likelihood of diagnosis and needed emergent
treatment. Acute pericarditis is a result of inflammation of the pericardium characterized
by chest pain, a pericardial friction rub, an elevated erythrocyte sedimentation rate
(ESR), and serial electrocardiographic abnormalities.
Gastrointestinal (GI) Tract
Pain arising from the gastrointestinal
tract, especially the esophagus, may give rise to chest discomfort
that is similar to angina pectoris. Gastroesophageal reflux disease is
the most common esophageal cause of noncardiac chest pain. Patients
describe the discomfort as a burning sensation or squeezing pain
located in the retrosternal area between the xyphoid and the
suprasternal notch. Clues to the diagnosis include an association of
symptoms with meals, posture, and relief by belching or antacids.
Medical management involves dietary modifications, smoking cessation,
and histamine type 2 (H2) antagonists or antacids. GI referral is
warranted when these interventions are unsuccessful in alleviating
symptoms. The pain of peptic ulcer disease may also be appreciated
high in the epigastrium or lower chest. The relationship to meals and
relative lack of response to nitroglycerine should help distinguish
this pain from angina pectoris.
Esophageal Spasm
Diffuse esophageal spasm is a neuromuscular disorder of the esophagus characterized
by chest pain and difficulty in swallowing. Note that nitroglycerin promptly relieves
esophageal spasm causing confusion in the diagnosis. Vigorous disordered contractions in
the body of the esophagus are induced by ingestion of cold liquids or normal swallowing
during a meal. Anxiety and stress are also common precipitating factors. There is usually
no exertional component but increased abdominal pressure from lifting, sit-ups, or running
can cause reflux. Diagnosis rests on history and verification of esophageal spasm by
manometric studies.
Pulmonary Origin
Pain of pulmonary origin characteristically has a distinct pleuritic
quality varying with the respiratory cycle. Intercostal nerves supply sensory afferents to
the costar parietal pleura. Inflammation arising from this region is appreciated in the
adjacent chest wall. Referred pain originating in the diaphragm is appreciated in the
ipsilateral shoulder. Differentiating features of pulmonic from musculoskeletal pain are
the more intense nature of pleuritic pain and the worsening of musculoskeletal pain by
extension, abduction, or adduction of the arm and shoulder. Pain centered around involved
muscle groups may also distinguish musculoskeletal from pleuritic chest pain.
-
Spontaneous pneumothorax tends to occur in young adult males producing sharp pleuritic
chest discomfort and dyspnea.
-
Pulmonary embolus may produce pleuritic pain, however, dyspnea, and tachypnea are most
frequent. Inciting factors for pulmonary embolus include the post-operative period after
long recumbent or inactive periods and following trauma where the same immobility may
result in venous stasis and thrombosis.
Chest Wall
Tietze's syndrome or costochondritis is a self-limiting discomfort. Its quality is
sharp or burning and is exacerbated by mechanical activity of the chest wall, specifically
respiration. The second or third costal cartilages on either side are the most common area
of involvement, but any of the costochondral articulations can be involved. Nonsteroidal
anti-inflammatory agents or aspirin may offer temporary relief but reassurance tends to be
as useful.
Other Possible Etiologies
Rarely, no etiology is found on standard evaluation of chest pain from the
cardiology or gastrointestinal consultation. Consideration of panic disorder should also
be included in the differential. Recent studies of some individuals with unexplained chest
pain and normal coronary arteries reveal abnormalities of flow in the cardiac
microcirculation and/or esophageal causes of chest pain. Visceral hypersensitivity may
also link non-chest pain and irritable bowel syndrome.
Summary
No individual variable separates patients with coronary chest pain from other likely
etiologies. Additive information gathered from a carefully directed history is necessary.
A combination of variables (sharp or stabbing pain, no history of angina or myocardial
infarction, and pain with pleuritic or positional components or pain reproduced by
palpation) define a very low risk group for having unstable angina or a myocardial
infarction. A cautious, yet practical, approach to the evaluation of chest pain with close
attention to symptoms and physical examination with further targeted testing and referral
leads to appropriate management.
References
-
Hurst JW, Atherosclerotic coronary heart disease: historical benchmarks, methods of
study and clinical features, differential diagnosis and clinical spectrum. In the Heart
Arteries and Veins. New York, NY. McGraw Hill Inc 1990, pp. 961-1028.
Reviewed by CAPT K. F. Strosahl, MC, USN, Cardiology/Computer
Assisted Program of Cardiology Specialty Leader, Cardiovascular Disease
Division, Portsmouth Naval Hospital, Portsmouth, VA (1999). |
Preface
· Administrative Section
· Clinical Section
The
General Medical Officer Manual , NAVMEDPUB 5134, January 1, 2000
Bureau
of Medicine and Surgery, Department of the Navy, 2300 E Street NW, Washington, D.C.,
20372-5300
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