CCH_chest_PainDifferential Diagnosis

CLINICAL PRESENTATION

The historical features of chest pain are useful in establishing the “pretest” probability for each disease in the differential diagnosis. Such probabilities guide the choice and interpretation of further diagnostic tests.

Acute myocardial infarction (AMI) produces a nonlocalized pressure, ache, or burning, the intensity of which ranges from minimal discomfort to severe pain. The pain is usually substernal and in the left chest, but can occur between the umbilicus and the neck. It frequently radiates to the shoulder or left arm and lasts several hours.

Stuttering presentations may last 12 to 24 hours. Determining the onset of constant pain is essential in deciding whether the patient is eligible for acute reperfusion therapy. Dyspnea, diaphoresis, nausea, and weakness are frequently associated symptoms. Occasionally, pain is felt only in a referred area, such as the arm, or via the vagus nerve, in the ear. Patients with AMI, particularly the elderly and diabetic patients, often present without pain (1), and this diagnosis must be suspected with the presentation of syncope or confusion.

Pain features not suggestive of AMI include stabbing, knife-like sensations or radiation to areas outside of cervicothoracic nerve segments, such as the legs or flanks (6). Very brief pain (lasting less than 5 seconds) or pain that is clearly pleuritic or exactly reproduced by bending or palpation is very unlikely to be of coronary origin (12).

The pain of angina is similar to that of AMI but is of shorter duration. A clear exertional pattern is helpful to the diagnosis; pain can also be provoked by effort, emotion, or exposure to cold. Prompt relief within 5 minutes from sublingual nitroglycerin is suggestive of angina but can also occur with esophageal spasm or placebo. Pain that is relieved with exertion and brought on by rest is not anginal. Angina is unstable when it increases in severity (duration, intensity, frequency), occurs with reduced activity or at rest, or has been present for less than 4 weeks. This diagnosis requires hospital admission or risk stratification prior to discharge from the ED.

Aortic dissection classically produces a severe tearing pain in the anterior chest radiating to the back, flank, or arm. The patient sometimes feels pain traveling down the back or flank as the dissection extends distally. The pain is frequently described as being migratory. Its onset is sudden, but it may be intermittent or wax and wane. Uncommonly, it presents as a myocardial infarction or as a chronic pain that has become worse. The pain has no relieving factors, and writhing, diaphoresis, dyspnea, nausea, and vomiting are commonly associated. A common error is to dismiss the diagnosis of aortic dissection because the pain gets better with nitroglycerin. This may be due to a decrease in the intraluminal pressure of the aorta after nitroglycerin. Associated symptoms, such as weakness, paralysis, syncope, and numbness or pain in an extremity, are also common and more specific for dissection.

Pericarditis produces a sharp or aching pain in the precordium that may radiate to the scapula, neck, or shoulder. Unlike AMI, it has a long duration (days), and can be continuous and severe or pleuritic. It is usually made worse by lying down or breathing; thus, the associated “shortness of breath.” Patients may insist on leaning forward to make themselves more comfortable.

Myocarditis can present with associated pericarditis. It also uncommonly masquerades as a myocardial infarction (13). Antecedent viral illness and younger age are diagnostic clues, but an in-hospital evaluation is necessary for definitive diagnosis of this uncommon cause of chest pain.

The most common presentation of pulmonary embolism (PE) is dyspnea, pleuritic pain, or hemoptysis (20). About 85% of cases of PE present with one or more of these nonspecific symptoms. Tachypnea is common, but tachycardia is found in only a minority of proven cases of PE. Large pulmonary emboli can produce circulatory collapse with syncope due to acute pulmonary hypertension and right heart failure. PE is mistaken for AMI about 7% of the time (20). Chest pain that is strictly reproducible is not consistent with PE, but rarely is present in these patients.

Pneumothorax may produce a severe, sudden stabbing pain in the affected side, or it may be asymptomatic. It has no characteristic pain radiation. It is made worse by breathing, is relieved by splinting, and is associated with shortness of breath and nonproductive cough. Pleurisy, an inflammation of the parietal pleura, is similar but does not have the associated symptoms or radiographic findings. Pneumonia can also cause pleuritic pain, but its association with productive cough, shortness of breath (at rest or exertion), and fever is often a helpful differentiating feature.

Pain may be due to an esophageal source. Pain from esophageal spasm is often indistinguishable from angina in quality, intensity, location, and radiation. Spasm has been described as a perfect mimic of acute myocardial ischemia. Esophageal reflux is a midline epigastric discomfort usually described as indigestion or burning. It lasts minutes to hours, and is worse after eating and lying down. It is associated with belching but not shortness of breath, and tends to be chronic; it may be associated with an acid taste.

TABLE 6.1. COMMON CAUSES OF CHEST PAIN

Organ System/Etiology	Chest Pain	Associated Symptoms
AMI, acute myocardial infarction; CHF, congestive heart failure; GI, gastrointestinal.
CARDIOVASCULAR
Acute myocardial infarction	Pressure, aching, burning	Dyspnea, palpitations, nausea, diaphoresis, radiation
Aortic dissection	Sudden, severe, tearing	Back pain, neurovascular deficits
Unstable angina	Same as AMI except episodic	Same as AMI
Pericarditis	Sharp, pleuritic, positional	Fever, dyspnea
Myocarditis	Same as AMI or pericarditis	Dyspnea, palpitations, CHF
RESPIRATORY
Pulmonary embolus	Sharp pleuritic or central ache	Dyspnea, cough, hemoptysis, leg swelling, risk factors
Pneumothorax	Sudden, sharp, pleuritic	Dyspnea, cough
Pneumomediastinum	Variable	Risks: cocaine, COPD, iatrogenic procedures
Pneumonia	Sharp, pleuritic	Cough, fever, dyspnea
Pleuritis	Sharp, pleuritic	Cough, fever
Mediastinitis	Variable	Fever, dyspnea, sepsis
Tumor	Chronic, variable	Weight loss
ESOPHAGEAL
Rupture: Boerhaave	Sudden, severe	Vomiting, hematemesis
Esophageal spasm	Similar to AMI	Reflux, nausea
Reflux esophagitis	Burning, worse supine	Reflux, nausea, sore throat
ABDOMINAL DISORDERS
Gastrointestinal	Constant, related to food	Vomiting, abdominal pain, GI bleeding
Cholecystitis	Constant or colicky	Vomiting, abdominal pain, jaundice, fever
Ruptured ectopic pregnancy	Sharp, pleuritic	Abdominal pain, vaginal bleeding, shoulder pain
MUSCULOSKELETAL
Ruptured cervical disc	Pain on neck movement	Neurologic signs, pain referred in root distribution
Costochondritis	Sharp, pleuritic	Localized tenderness and inflammation
Herpes zoster	Burning, lancinating	Dermatomal distribution of pain, rash, paresthesias
Postherpetic neuralgia	Burning, lancinating	History of zoster

• ir" />View table