Provocation
The patient should be asked about factors that provoke or make the pain worse:

• Discomfort that reliably occurs with eating is suggestive of upper gastrointestinal disease.

• Postprandial chest pain may be due to gastrointestinal or cardiac disease; in the latter case it can be a marker of severe myocardial ischemia (eg, left main or three-vessel CAD.

• Chest discomfort provoked by exertion is a classic symptom of angina, although esophageal pain can present similarly.

• Other factors that may provoke ischemic pain include cold, emotional stress, meals, or sexual intercourse.

• Pain made worse by swallowing is likely of esophageal origin.

• Body position or movement, as well as deep breathing, may exacerbate chest pain of musculoskeletal origin.

• Truly pleuritic chest pain is worsened by respiration and may be exacerbated when lying down.

• Causes of pleuritic chest pain include pulmonary embolism, pneumothorax, viral or idiopathic pleurisy, pneumonia, and a pleuropericarditis

Palliation
Factors that make the pain better should be established:

• Pain that

  is reliably and repeatedly palliated by antacids or food is likely of gastro-esophageal origin.

• Pain that responds to sublingual nitroglycerin may be of either esophageal

  or cardiac etiology.

• Relief of pain following the administration of a "GI cocktail" (eg, viscous lidocaine and antacid) does not reliably distinguish gastrointestinal from ischemic chest pain. On the other hand, pain that abates with cessation of activity strongly suggests an ischemic origin.

• The pain of pericarditis typically improves with sitting up and leaning forward.

Severity
The severity of pain is not a useful predictor of CAD. As many as one-third of myocardial infarctions may go unnoticed by the patient.