A 46-year-old man comes to the emergency department due to chest pain and shortness of breath over the last 10 hours. The pain is sharp and does not radiate. He says that taking shallow breaths helps to avoid the pain. He considers himself healthy and has never had symptoms like this before. The patient takes over-the-counter antacids for frequent heartburn. He has a 25-pack-year smoking history, but does not use alcohol or recreational drugs. His father died from a myocardial infarction at age 47. He works as a long-haul truck driver. Temperature is 36.7 C (98 F), blood pressure is 110/70 mm Hg, pulse is 110/min, and respirations are 31/min. BMI is 29 kg/m2. ECG shows sinus tachycardia. Chest x-ray is shown:
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What is the most likely diagnosis in this patient?
This patient's clinical presentation – pleuritic chest pain, dyspnea, tachypnea, and tachycardia in a long-distance truck driver – is most consistent with acute pulmonary embolism (PE). Other signs and symptoms of PE include cough, hemoptysis, and/or lower extremity pain or swelling (ie, deep venous thrombosis). Some patients may be asymptomatic or have other nonspecific symptoms (eg, lightheadedness).
Chest x-ray is commonly normal in acute PE (as in this patient), but it can help rule out other causes of chest pain and dyspnea (eg, pneumonia, pneumothorax, aortic dissection, pericardial effusion). Sometimes, chest x-ray shows nonspecific findings that may be associated with PE (eg, atelectasis, pleural effusion), and occasionally it may show one of several findings that are highly suggestive of PE:
Westermark sign: peripheral hyperlucency of the pulmonary arterial tree resulting from blood flow being cut off by the PE.
Hampton hump: peripheral, wedge-shaped lung opacity representing pulmonary infarction. An ipsilateral pleural effusion is also commonly present with this sign (pulmonary infarction is the typical cause of PE-associated pleural effusion).
Fleischner sign: Enlargement of the pulmonary artery resulting from increased pressure proximal to the PE.
Regardless of chest x-ray findings, chest CT angiography is the gold standard in confirming and ruling out acute PE.
(Choice A) Acute myocardial infarction must be considered in the differential diagnosis of chest pain and dyspnea, especially in patients who smoke or have family history of premature coronary heart disease. Chest x-ray is commonly normal, but this patient's pleuritic chest pain and lack of ischemic ECG changes make the diagnosis less likely.
(Choice B) An ascending aortic dissection typically presents with sudden-onset, tearing chest and back pain in the setting of uncontrolled hypertension. Chest x-ray may reveal a widened mediastinum or an irregular aortic contour with inward displacement of atherosclerotic calcification.
(Choice C) Peptic ulcer perforation presents with acute abdominal pain with radiation to the back or right shoulder and signs of peritonitis. Upright chest x-ray may reveal pneumoperitoneum (gas within the peritoneal cavity) with free air under the diaphragm.
(Choice D) Patients with pneumothorax (air in the pleural space) typically present with pleuritic chest pain and/or dyspnea. Chest x-ray reveals a peripheral or apical radiolucency, along with absence of distal lung markings.
Educational objective:
Acute pulmonary embolism (PE) typically presents with dyspnea, pleuritic chest pain, tachypnea, and tachycardia. Chest x-ray is commonly normal or shows nonspecific findings, but it can help rule out other competing diagnoses (eg, pneumonia, pneumothorax) and occasionally shows findings highly suggestive of PE.