This patient's most likely diagnosis is acute myocardial infarction. The pain associated with this diagnosis is deep and visceral; it is typically described as heavy, squeezing, and crushing, and less commonly as stabbing or burning. It is similar in character to the discomfort of angina pectoris but commonly occurs at rest, is usually more severe, and lasts longer. Unlike angina, it is not relieved with rest if precipitated by exertion. Typically, the pain involves the central portion of the chest and/or the epigastrium, and, on occasion, it radiates to the arms. Less common sites of radiation include the abdomen, back, lower jaw, and neck. It is often accompanied by weakness, sweating, nausea, vomiting, anxiety, and a sense of impending doom. Additional physical exam findings include anxiousness, restlessness, pallor, diaphoresis, cool extremities, an S3 or S4 gallop, paradoxical splitting of the second heart sound, a transient midsystolic or late systolic apical systolic murmur due to dysfunction of the mitral valve, pericardial friction rub with transmural STEMI. Notable ECG findings include ST-T segment (>1-mm elevation or depression) and T-wave (inversion) changes suggest ischemia; Q-wave suggests accomplished infarction; ST-elevation is absent in unstable angina and NSTEMI; new bundle branch block or sustained ventricular tachycardia indicates a higher risk of progression to infarction.
Burning epigastric pain is the most classic symptom of peptic ulcer disease. The pain also may be described as sharp, dull, an ache, or an "empty" or "hungry" feeling. Pain may be relieved by ingestion of milk, food, or antacids, presumably due to buffering and/or dilution of acid.
Pneumonia is characterized by acute or subacute onset of fever, cough with or without sputum production, and dyspnea. Other common symptoms include sweats, chills, rigors, chest discomfort, pleurisy, hemoptysis, fatigue, myalgias, anorexia, headache, and abdominal pain. Common physical findings include fever or hypothermia, tachypnea, tachycardia, and arterial oxygen desaturation. Many patients appear acutely ill. Chest examination often reveals inspiratory crackles and bronchial breath sounds. Dullness to percussion may be observed if lobar consolidation or a parapneumonic pleural effusion is present.
Pericarditis is usually preceded by viral infections, especially infections with coxsackieviruses and echoviruses. It is characterized by chest pain, which is usually pleuritic and postural (relieved by sitting). The pain is substernal but may radiate to the neck, shoulders, back, or epigastrium. Dyspnea may also be present and the patient is often febrile. A pericardial friction rub is characteristic. The ECG usually shows generalized ST and T wave changes and may manifest a characteristic progression beginning with diffuse ST elevation, followed by a return to baseline and then to T wave inversion.
Nearly all pulmonary emboli arise from deep venous thrombosis (DVT) in the lower extremity or pelvic veins. Risk factors for DVT and PE are similar in children and adults and include conditions that impair venous return, conditions that cause endothelial injury or dysfunction, and underlying hypercoagulability disorders. Larger emboli cause acute dyspnea, pleuritic chest pain, or both. Dyspnea may be intermittent or occur only with exercise. Less common symptoms include cough and hemoptysis. The most common signs of PE are tachycardia and tachypnea. Less commonly, patients have hypotension, a loud 2nd heart sound (S2) due to a loud pulmonic component (P2), and crackles or wheezing. ECG most often shows tachycardia and various ST-T wave abnormalities, which are not specific for PE. An S1Q3T3 or a new right bundle branch block may indicate the effect of abrupt rise in right ventricular pressure on right ventricular conduction; these findings are moderately specific but insensitive for PE.