BACKGROUND

• 1% of all ambulatory visits in the US are for chest pain. The epidemiology of chest pain is very different when patients present to an ambulatory clinic compared with emergency settings, with a larger proportion of patients presenting with benign etiologies.
• In a series of studies of ambulatory care patients presenting with chest pain, 30-40% had pain of a musculoskeletal source, 10-20% had a GI source, 10-15% had stable angina, 5 percent had respiratory causes, and 1.5-4% had acute ischemia.

ETIOLOGIES

The classical symptoms of different sources of acute chest pain can be subjective and difficult for patients to characterize. Care should be taken to maintain a low threshold for referral. Both history and physical exam have been shown to have a poor sensitivity and specificity to distinguish benign from life-threatening causes of chest pain.

• Cardiovascular:
  • Ischemic cardiac causes:
    • ACS and stable angina: deep, poorly localized chest or arm discomfort reproducibly associated with exertion and relieved with rest or nitroglycerine. May be provoked by emotional distress, associated with radiation, diaphoresis, dyspnea, nausea, syncope, and hypotension. Expect variable characterization of symptoms, and atypical (sometimes pain free) presentations in women, diabetic patients, and the elderly.
    • If symptoms are new, changing, or progressive, urgent referral to emergency department is appropriate.
  • Non-ischemic cardiac causes:
    • Heart failure: chest discomfort typically associated with dyspnea, orthopnea, pulmonary edema and lower extremity edema.
    • Acute thoracic aortic dissection: severe chest or back pain which can also radiate to the abdomen, classically with a ‘tearing’ quality.
    • Pericarditis: pleuritic chest pain improved by leaning forward. Also associated with classic ECG changes (diffuse ST elevation, PR depression, without T-wave inversion) and an audible friction rub.
    • Takotsubo/Stress Cardiomyopathy: substernal chest pain of ischemic character with onset in the setting of acute emotional distress, more common in female patients
• Pulmonary:
  • Pneumonia: presentation with fever, chills, productive cough, pleuritic pain.
  • Pulmonary embolism: acute onset dyspnea, tachycardia, pleuritic chest pain, with or without extremity symptoms to suggest the presence of DVT.
  • COPD: under-appreciated source of chest tightness. Typically present with chest discomfort in the setting of dyspnea related to asthma or COPD exacerbation.
  • Acute Chest Syndrome: infiltrate and fever, dyspnea, cough, and hypoxia in patients with sickle cell anemia
  • Sarcoidosis: chest pain often present in patients with either pulmonary or cardiac sarcoidosis. Higher degree of concern for cardiac sarcoidosis if syncope, dizziness, and ECG changes consistent with conduction disease.
• Musculoskeletal:
  • Chest wall pain: localized muscle tension or tenderness, pain reproducible by palpation, absence of cough.
  • Costochondritis: reproducible pain to palpation specifically localized to the parasternal/chostochondral joints
  • Injury or Trauma: Rib fractures, neoplasm, bruising of the ribs

• Gastrointestinal:
  • GERD: substernal burning with significant anginal character, acid regurgitation, sour taste, can radiate and persist for many hours. Often occurs after meals, lying down, or with emotional distress.
  • Esophagitis: burning retrosternal pain which can occur after pill-associated injury, viral or fungal esophageal infection in immunodeficiency, or via food allergen triggers in eosinophilic esophagitis.
  • Esophageal Spasm: painful, self-resolving spasm of smooth muscle of esophagus
  • Esophageal injury: severe pain, typically in the setting of vomiting or dry heaving
• Psychological:
  • Anxiety and Panic Disorder: typically spontaneous and rapid onset episodes associated with a discrete triggering event, perpetuated by fear of ongoing panic episode. Caution because hyperventilation can also cause true demand ischemia in patients with underlying CAD. 

EVALUATION

The first decision point in evaluating patients with acute chest pain is determining whether the pain is likely to reflect cardiac ischemia or ACS. Any patient with chest pain that is exertional or with ECG changes should be seen in an acute care setting for troponin levels and cardiac stress testing.

• History:  History and physical exam not sensitive or specific for diagnosing ACS in low-prevalence setting.  The most specific characteristics studied are: absence of chest wall tenderness on palpation, diaphoresis, pain worse with exertion, radiation to the arm or shoulder, and pressure-type pain.
• Risk Factors: Age > 60 and male gender are associated with increased likelihood of ACS. Comorbidities such as DM, smoking, HTN, HLD, however, only weakly predict ACS (LR+= 2.1 in patients < 65, LR+= 1.1 in patients > 65). A history of prior angina or ACS episodes is associated with increased likelihood of true ischemia.
• Physical Exam:
  • Early vital sign measurement is important for evidence of hypotension, tachycardia, and hypoxia. If concern for dissection, BP measurement in both arms. If concern for tamponade, assessment of pulsus paradoxus.
  • Auscultation for new third heart sound, friction rub, irregular heart rhythm, pulmonary edema or wheezing.
  • Assessment of JVP, upper and lower extremity warmth and perfusion for signs of impending shock.
  • Skin exam for rashes, palpation over chest for evidence of musculoskeletal pain source.
• Labs: if available, labs including serum troponin, lactate, CBC and CMP. D-dimer, VBG as appropriate.
• Imaging: CXR appropriate in most patients. Can also consider CT chest if concern for dissection, PE is high.
• ECG: 12 lead ECG to assess for evidence of ST segment changes, new left bundle branch block, presence of Q waves or new onset T wave inversions.

TREATMENT

Treatment of chest pain involves addressing the underlying physiologic source. A common list of treatments to the most frequent causes of chest pain below:

• Acute Coronary Syndrome (ACS): These patients should be sent directly to the ED or can be directly admitted to cardiology. Patients with STEMIs will go directly to the cardiac catheterization. Initial oral medications can be given in the outpatient setting:
  • Aspirin 325 mg PO once
  • Atorvastatin 80 mg PO once
  • Metoprolol tartrate 12.5 mg PO (hold for a heart rate <60 BPM and/or the presence of acute heart failure or cardiogenic shock)
  • Nitroglycerin 0.4 mg sublingually (hold if signs of inferior or right-sided myocardial infarction)
• Costochondritis: Costochondritis is a self-limited condition that resolves spontaneously over weeks. Adjunct therapy can help alleviate symptoms and may reduce the duration of symptoms.
  • Heat/Ice, stretching exercises, NSAIDS and/or APAP, Muscle rubs (menthol or ASA-based creams are most common)
• Gastroesophageal reflux (GERD) In the absence of ‘red flag’ symptoms or signs, H2 blocker or PPI can be effective. Pain is typically caused from esophagitis rather than reflux itself.
  • Famotidine (H2B) 20-40 mg QD or BID (favored over PPI if only occasional symptoms or if relative contraindication to PPI such as recurrent C. difficile infection)
  • Omeprazole (PPI) 20-40 mg QD or BID (may be less effective if taken prn with meals)
  • Sucralfate or bismuth solutions
  • Avoidance of potassium or iron supplementation or doxycycline if possible (or these medications and all PO intake should occur with 30-60 minutes of post-prandial upright posture)
• Pneumonia: If CURB-65 and other subjective/objective measures suggest safe outpatient treatment of infection, PO antibiotics
  • Cephalosporin + doxycycline; levofloxacin, per IDSA guidelines and local antibiogram
• Pulmonary embolism: If the Pulmonary Embolism Severity Index (PESI score) dictates a low risk of mortality, then these patients can be treated as an outpatient with oral anticoagulation.
  • NOAC or DOAC initiation with close outpatient follow-up
• Heart failure: Cardiac stretch and pulmonary edema are typically the underlying cause of chest pain in these patients.
  • Lasix, torsemide, or bumex, typically 1.5-2x prior dose for 3 days
• Pericarditis: Low-risk patients can be treated in outpatient setting using combination therapy for 7-14 days.
  • NSAIDS: aspirin 625 mg – 1000 mg or ibuprofen 600 – 800 mg TID
  • Colchicine 0.6 mg BID
  • Activity restriction to reduce symptoms
• Anxiety/Panic: In the acute setting, reasonable to use low-dose benzodiazepine: long-term management is via SSRI and CBT.
  • SSRI or SNRI other medication for treatment of anxiety (long-term medication) with CBT

WHEN TO REFER

• Referral to emergency department for further management of suspected ACS
• For angina with intermediate pretest probability of CAD, referral to cardiology for cardiac stress testing and risk stratification
• For GERD unresponsive to initial 6-8 week PPI trial with negative H. pylori, referral to gastroenterology