A thorough description of the pain is an essential first step in the diagnosis of chest pain
Quality of the pain
The patient with myocardial ischemia often vigorously denies feeling chest "pain." More typical descriptions include squeezing, tightness, pressure, constriction, strangling, burning, heart burn, fullness in the chest, a band-like sensation, knot in the center of the chest, lump in the throat, ache, heavy weight on chest (elephant sitting on chest), like a bra too tight, and toothache (when there is radiation to the lower jaw). In some cases, the patient cannot qualify the nature of the discomfort, but places his or her fist in the center of the chest (the "Levine sign").
A "sharp" or "stabbing" pain with a pleuritic or positional component that is fully reproducible by palpation, in patients who have no history of angina or myocardial infarction, probably have low-risk for the episode being ischemic.
Region or location of pain
Ischemic pain is a diffuse discomfort that may be difficult to localize. Pain that localizes to a small area on the chest is more likely of chest wall or pleural origin rather than visceral. Referred pain is an exception.
Radiation The pain of myocardial ischemia may radiate to the neck, throat, lower jaw, teeth, upper extremity, or shoulder. A wide extension of chest pain radiation increases the probability that it is due to myocardial infarction. Radiation to the right arm may be a particularly useful finding. In one study 48 of 51 patients who presented to an emergency department with chest pain that radiated to the right arm suffered from coronary disease; 41 had a myocardial infarction. Radiation to both arms is an even stronger predictor of acute myocardial infarction. Acute cholecystitis can present with right shoulder pain, although concomitant right upper quadrant or epigastric pain is more typical than chest discomfort. Chest pain that radiates between the scapulae may be due to aortic dissection.
The time course of the onset of chest pain may be a very useful distinguishing feature:
- The pain associated with a pneumothorax or a vascular event such as aortic dissection or acute pulmonary embolism typically has an abrupt onset with the greatest intensity of pain at the beginning.
- The onset of ischemic pain is most often gradual with an increasing intensity over time. A crescendo pattern of pain can also be caused by esophageal disease.
- "Functional" or nontraumatic musculo-skeletal chest pain might have a much more vague onset.
- The duration of pain is also helpful. Chest discomfort that lasts only for seconds or pain that is constant over weeks is not due to ischemia. A span of years without progression makes it more likely that the origin of pain is functional.
- The pain from myocardial ischemia generally lasts for a few minutes; it may be more prolonged in the setting of a myocardial infarction.
- Myocardial ischemia may demonstrate a circadian pattern. It is more likely to occur in the morning than in the afternoon, correlating with an increase in sympathetic tone.