This patient’s EKG demonstrates alternating amplitudes of QRS complexes, a phenomenon known as electrical alternans. This is caused by the heart swinging back and forth within a large pericardial effusion. The patient is tachycardic and borderline hypotensive, which should raise concern over impending cardiac tamponade. The next best investigation to definitively diagnose a large pericardial effusion with possible tamponade would be a cardiac sonogram (Choice B). This investigation could also guide treatment with pericardiocentesis in the event of hemodynamic decompensation and the development of obstructive shock. Other EKG signs of a large pericardial effusion are diffusely low QRS voltages and sinus tachycardia. Chest radiography (Choice C) may show an enlarged cardiac silhouette in this case and evaluate for alternative diagnoses (i.e. pneumothorax, pleural effusions, pneumonia, atelectasis), however, cardiac echocardiography is the best next investigation. CT pulmonary angiography (Choice D) would demonstrate the presence of a pericardial effusion along with differences in cardiac chamber size indicative of tamponade. Still, bedside cardiac sonogram is a faster test that prevents a delay in diagnosis. Sending a potentially unstable patient for a CT scan may also be dangerous. Arterial blood gas testing (Choice A) has no role in diagnosing pericardial effusion or cardiac tamponade. Correct Answer: B

All patients who present to the emergency department with chest pain should be evaluated for the top life-threatening conditions causing chest pain. Some of these include myocardial infarction, pulmonary embolism, esophageal rupture, tension pneumothorax, cardiac tamponade, and aortic dissection. Many of these diagnoses can be ruled-out or deemed less likely with a detailed history, physical exam, EKG, and sometimes imaging and blood testing. This patient presents with vague, burning chest pain, nausea, and tachycardia on exam. Pulmonary embolism (Choice A) is hinted by the patient’s tachycardia, but the patient has no tachypnea or risk factors mentioned for PE. Additionally, the chest X-ray findings demonstrate an abnormality that can explain the patient’s symptoms. Pancreatitis (Choice B) and Gastroesophageal reflux disorder (Choice D) are also possible diagnoses, especially with the location and description of the patient’s pain. However, Chest X-ray imaging offers an explanation for the patient’s symptoms. The patient’s Chest X-ray demonstrates the presence of pneumoperitoneum. In the presence of NSAID use, this radiological finding raises concern over a perforated viscus from advanced peptic ulcer disease (Choice C). Peptic ulcer disease (PUD) is most commonly caused by Helicobacter pylori infection, but NSAIDs, iron supplements, alcohol, cocaine, corrosive substance ingestions, and local infections can cause PUD. PUD is a clinical diagnosis which can be confirmed visually via endoscopy. The treatment for PUD includes initiation of a proton pump inhibitor (H2-receptor blockers are 2nd line), avoiding the inciting agent, and H.pylori antibiotic regimens in confirmed H.pylori cases. The treatment for a perforated peptic ulcer with pneumoperitoneum is IV fluids, IV antibiotics, Nasogastric tube placement, and surgical consultation for repair.