--From [Yale-G First Aid: Crush USMLE Step 2CK and Step 3] By Dr. Yale Gong, USMLE-Certified, Sr. Advisor of www.medicine.net
Chest pain is one of the most common symptoms for most cardiovascular diseases, respiratory diseases, and some upper abdominal disorders. Thus, its differential diagnosis is highly important.
It is the most common cause of chest pain, which is usually moderate and localized, exacerbated with inspiration, coughing, sneezing, or chest palpation (reproducible). ECG is normal. Treatment with an anti-inflammatory drug (ibuprofen, etc.) is effective.
It mostly refers to “stable angina”, a paroxysmal chest pain resulting from cardiac ischemia mostly caused by atherosclerotic coronary arteries. Stable angina is the type when the chest pain is precipitated by predictable factors (exercise, exertion, etc.). Unstable angina is angina that occurs at any time and carries more risk for myocardial infarction.
Major risk factors: Age (male > 45, female > 55 y/a), male gender, smoking, hypertension, diabetes, heredity (including race, family history < 55 y/a), atherosclerosis, dyslipidemia (LDL > 200 mg/dL, HDL < 40 mg/dL), physical inactivity, obesity, stress, excess alcohol use, and postmenopausal women.
Clinical features: 1. Pressing or squeezing chest pain radiating to the left jaw or arms, lasting for 15 sec—15 min. 2. Precipitating factors: exertion, anxiety, meals, and coldness. 3. Pain relief: Nitroglycerin, resting. 3. ECG: ST-T depression.
Treatment: (1) Nitrates; (2) Beta1 receptor blockers (Atenolol, metoprolol). (3) Ca-channel blockers (verapamil, etc.). (4) Unstable angina: Hospitalize and treat the patient with aggressive aspirin, nitrates, beta-R blockers, and heparin, and be ready for revascularization.
Myocardial infarction (MI)
MI is ischemic myocardial necrosis as a result of an abrupt reduction in the coronary blood flow to a segment of myocardium, usually due to a thrombotic occlusion of a coronary artery previously narrowed by atherosclerosis. MI is associated with a 30% mortality rate and 50% pre-hospital deaths. Emergency management at initial symptoms is life-saving! Risk factors: Same as angina.
Clinical features: 1. Characteristic symptoms: severe, crushing, prolonged chest pain more severe than angina; associated with dyspnea, anxiety, diaphoresis, nausea, vomiting, weakness, low fever, sense of impending doom, and syncope (in elderly). Painless and atypical MI can be up to 1/3 cases and more likely in postoperative or diabetic patients and the elderly. Sudden cardiac death can occur due to ventricular fibrillation (V-fib). 2. Cardiogenic shock signs: seen with > 40% of MI—BP decrease, S3 gallop, and rales. 3. ECG: peaked T waves (early), ST-segment elevation (transmural infarct) or depression (subendocardial lesion), or Q waves (necrosis, late).
Treatment: 1. “ABC” first—airway, breathing, and circulation. Supplemental oxygen. 2. Treat sustained ventricular arrhythmia or heart failure rapidly. 3. Beta1-R blockers (metoprolol): shown reduced post-MI mortality rate. 4. Nitrates. 5. Antiplatelet therapy: Aspirin (PO). 6. Thrombolytic therapy. 7. Analgesics: IV opiates (morphine) are important to relieve pain, to supply relaxation and sedation, and to alleviate CVS and respiratory stress effectively. 8. ACE inhibitors (Angiotensin-converting enzyme inhibitors, ACE-I): It has shown reduced post-MI mortality. 9. Hypolipidemic therapy: Atorvastatin should also be started early and before percutaneous coronary intervention (PCI). 10. Coronary angiography and angioplasty.
Myocarditis
It’s acute or chronic infection or inflammation of the myocardial cells, leading to reduced cardiac contractility and output, and possibly heart failure. It’s usually preceded by an upper respiratory viral infection (fever, sore throat) and associated with a vague chest pain and increased creatine kinase (CK). ECG shows abnormal conduction or Q waves. Be cautious that a severe type of viral myocarditis may progress rapidly to myocardial infarction with a senior age or direct heart failure with a young age.
Treatment: Supportive and symptomatic therapy is the mainstay of therapy. anti-inflammatory drugs are usually ineffective and alcohol drinking should be avoided.
Pericarditis
It’s the inflammation of the pericardial lining around the heart. It may be preceded by a viral illness. Chest pain is sharp, pleuritic, and positional—worse with lying down and relieved by sitting up. Pericardial rub often exists. ECG usually shows diffuse ST elevation without Q waves. CK is mostly normal. It responds well to anti-inflammatory drugs.
Pleuritis
Mostly after lung infection, with sharp chest pain that is worse on inspiration and certain position; tenderness, friction rub or dullness may be present. CXR or CT scan is the best diagnostic test. Treat primary disease and complications.
Pneumonia
Moderate chest pain with fever, cough, sputum, +/- hemoptysis. CXR (CT if complications or a tumor is suspected) is the best test. Treat with antibiotics and supportive therapies.
Typically sudden, sharp, pleuritic chest pain and dyspnea; absent breath sounds; mediastinum shifted to the opposite site—suspect of tension pneumothorax—requiring urgent intercostal needle puncture. Non-tension pneumothorax can wait for CXR confirmation and natural relief.
Typical severe, sharp, tearing chest pain radiating to the back; loss of pulses, unequal BP between arms, or aortic insufficiency; neurologic signs; mediastinum widened on CXR. MI may occur if dissection extends into coronary artery (Cor-A). Diagnosis is confirmed by transesophageal echocardiography (TEE), CT scan, or aortography. Treatment: Ruptured AA or impending rupture requires IV fluid and packed RBC followed by an emergency surgery to save life.
Pulmonary (artery) embolism (PE)
Mostly caused by deep vein thrombosis (DVT) from the lower limbs. Sudden chest pain, dyspnea, tachycardia, cough, and hypoxemia, usually 3-5 days after a surgery or long immobility. The chest pain is usually pleuritic but may resemble angina. CT pulmonary angiography has supplanted V/Q scanning as the preferred means of diagnosis.
A common congenital valvular abnormality characterized by transient non-angina chest pain with a typical midsystolic click murmur. Echocardiography is the best method for diagnosis. Most cases are asymptomatic and not in need of treatment.
Pulmonary hypertension (HTN)
History of chronic cardiovascular or pulmonary diseases; dull chest pain with symptoms and signs of right ventricular (RV) failure. Treat primary disease.
Gastric diseases
Gastroesophageal reflux disease--GERD (burning chest pain, acid reflux, bad taste, relief with antacids); stomach spasm; peptic ulcer disease--PUD (epigastric pain before or after eating). Complex treatment.
Pancreatitis
Post-meal persisting sharp epigastric pain radiating to the back, with nausea, vomiting, fever, and increased amylase and lipase levels. Complex treatment.
Gallbladder disease
Post-meal right upper quadrant (RUQ) abdominal pain with tenderness, nausea, vomiting, and/or jaundice usually in a middle-aged obese woman. Complex treatment.
Hiatal hernia
Burning chest or epigastric pain; nausea, vomiting; reflux of food; relief with antacids; surgery may be needed.
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