Chest pain

Scope of the problem Acute chest pain is the presenting complaint in roughly 3% of emergency department (ED) patients. The diagnostic possibilities range from the immediately life-threatening (acute coronary syndrome [ACS], comprised of acute myocardial infarction [AMI] and unstable angina [USA], aortic dissection, pulmonary embolism [PE] and ruptured esophagus) to the self-limiting (chest wall strain), and the common (gastroesophageal reflux disease) to the unusual (herpes zoster). Although the etiology of the chest pain may remain unidentified in a significant proportion of patients, which can be frustrating to both the patient and provider, it is imperative that the clinician recognizes and treats life-threatening causes. Anatomic essentials When considering the differential diagnosis of the patient with chest pain, it is helpful to consider the five organ systems in the thorax: cardiac (heart and pericardium), pulmonary (lungs and pleura), gastrointestinal (esophagus and upper abdominal contents), vascular (aorta and great vessels) and musculoskeletal (chest wall). Visceral pain from internal structures such as the heart, lungs, esophagus and aorta may be difficult for the patient to define. Pain may be described as a discomfort or strange sensation, and it is often challenging for the patient to discern an exact location. Somatic pain from chest wall structures is often more localizable and easier for the patient to characterize. Pain may be sharp or stabbing, brought on by movement or position, and can often be pinpointed. Referred pain from irritation or inflammation of the upper abdominal contents may be perceived as pain in the chest or upper back. A differential diagnosis based on these structures is given in Table 17.1.