Differential Diagnosis of Chest Pain: A Comprehensive Guide for Clinicians

Introduction

Chest pain is a frequently encountered complaint in clinical practice, presenting a significant diagnostic challenge due to its wide range of potential etiologies, from benign to life-threatening conditions. Effective and timely diagnosis is paramount to rule out serious pathologies such as acute coronary syndrome (ACS), pulmonary embolism (PE), aortic dissection, and esophageal rupture before considering less critical causes. Understanding the nuances of chest pain, including its characteristics, associated symptoms, and risk factors, is crucial for healthcare professionals. This article aims to provide a comprehensive overview of the differential diagnosis of chest pain, emphasizing the importance of a systematic approach to evaluation and management.

Etiology of Chest Pain

Determining the underlying cause of chest pain requires a thorough understanding of the different pain mechanisms. Chest pain can broadly be categorized into visceral and somatic pain, each with distinct characteristics.

Visceral Pain: This type of pain originates from the internal organs and is often described as dull, deep, pressure-like, or squeezing. Patients typically struggle to pinpoint visceral pain to a specific location, often gesturing with a wide hand movement rather than a single finger. A key feature of visceral pain is referred pain, where the pain is felt in areas distant from the affected organ. This occurs due to the convergence of visceral and somatic nerve fibers at the spinal cord. For instance, cardiac ischemic pain can radiate to the left or right shoulder, jaw, or left arm. Accompanying symptoms like nausea and vomiting are also common indicators of visceral pain. Furthermore, diaphragmatic irritation can manifest as referred pain in the shoulders.

Somatic Pain: In contrast, somatic pain is more localized and arises from the skin, muscles, bones, and joints. Patients can usually point to the precise location of somatic pain. Descriptors often used for somatic pain include sharp, stabbing, or poking. Referred pain is less common with somatic pain compared to visceral pain.

Understanding these pain characteristics is essential for guiding the diagnostic process and narrowing down the differential diagnosis of chest pain.

Epidemiology of Chest Pain

Chest pain is a prevalent symptom, particularly in emergency department (ED) settings. It is the second most common complaint in the ED, accounting for approximately 5% of all visits. Given the potential for life-threatening etiologies, a systematic and efficient evaluation is crucial.

Studies have provided insights into the prevalence of various causes of chest pain in the ED. Life-threatening conditions, while less frequent than benign causes, require immediate attention. The approximate percentages of life-threatening causes in patients presenting to the ED with chest pain, based on research, include:

Acute Coronary Syndrome (ACS): Approximately 31%
Pulmonary Embolism (PE): Around 2%
Pneumothorax (PTX): Occurrence rates vary and may be underreported in some studies.
Pericardial Tamponade: Rare, often grouped with pericarditis which is around 4%.
Aortic Dissection: Approximately 1%
Esophageal Perforation: Unreported, but a critical condition to consider.

Other common, but generally less immediately life-threatening, causes of chest pain seen in the ED include:

Gastroesophageal Reflux Disease (GERD): Around 30%
Musculoskeletal Causes: Approximately 28%
Pneumonia/Pleuritis: About 2%
Herpes Zoster (Shingles): Around 0.5%
Pericarditis: Unreported in some studies but can be around 4% when considering pericardial conditions.

These epidemiological data highlight the importance of considering both serious and benign conditions in the differential diagnosis of chest pain.

History and Physical Examination in Chest Pain Evaluation

A comprehensive history and physical examination are the cornerstones of chest pain evaluation.

History

A detailed history is essential to characterize the chest pain and identify potential underlying causes. Key aspects to explore include:

Onset: Determine when the pain started and what the patient was doing at the time of onset. Was it sudden or gradual? Was it associated with exertion, rest, or specific activities?
Location: Ask the patient to describe the pain location. Is it localized or diffuse? Can they point to it with one finger or is it a broader area?
Duration: How long does the pain last? Is it constant or intermittent?
Character: Encourage the patient to describe the pain in their own words (e.g., sharp, dull, pressure, burning, squeezing).
Aggravating/Alleviating Factors: Identify factors that worsen or relieve the pain. Is it related to exertion, breathing, eating, or body position? Inquire about new workout routines, sports activities, or lifting. Ask about any medications tried and their effect.
Radiation: Does the pain radiate to other areas, such as the arm, jaw, back, or shoulder? Radiation can suggest visceral pain.
Timing and Pattern: How frequently does the pain occur? Are there patterns or triggers?

Inquire about associated symptoms, which can provide crucial diagnostic clues:

Shortness of Breath (Dyspnea): Suggests cardiac or pulmonary involvement.
Nausea and Vomiting: May indicate visceral pain, particularly cardiac or gastrointestinal.
Fever: Points towards infection, such as pneumonia or pleuritis.
Diaphoresis (Sweating): Often associated with ACS.
Cough: Suggests pulmonary issues like pneumonia, bronchitis, or pulmonary embolism.
Dyspepsia (Indigestion): May indicate GERD or, less commonly, ACS.
Edema (Swelling): Can be related to heart failure or deep vein thrombosis (DVT).
Calf Pain or Swelling: Raises suspicion for DVT, a risk factor for PE.
Recent Illness: Recent upper respiratory infection (URI) may suggest pneumonia or pleuritis.

Risk factor assessment is critical for evaluating the likelihood of serious conditions:

ACS Risk Factors: Prior myocardial infarction (MI), family history of cardiac disease, smoking, hypertension (HTN), hyperlipidemia (HLD), diabetes mellitus.
Pulmonary Embolism (PE) Risk Factors: Prior DVT or PE, hormone use (oral contraceptives, hormone replacement therapy), recent surgery, cancer, prolonged immobility, pregnancy.
Gastrointestinal Risk Factors: Recent GI procedures (endoscopy), history of GERD.
Substance Abuse: Cocaine and methamphetamine use are associated with ACS.

Review the patient’s medical history, including cardiac history, coagulopathies, kidney disease, and family history of cardiac disease. Social history, particularly tobacco and drug use, is also relevant.

After considering life-threatening causes, explore other possibilities. In patients with productive cough or recent URI, pneumonia should be considered. GERD is a common cause, so inquire about reflux symptoms. Musculoskeletal pain should be considered in patients with new exercise routines or recent trauma.

Physical Examination

The physical examination should be comprehensive and focus on evaluating systems involved in chest pain. Key components include:

Vital Signs: Measure a full set of vitals, including blood pressure (BP) in both arms to assess for discrepancies suggestive of aortic dissection.
General Appearance: Observe for signs of distress, diaphoresis, pallor, or cyanosis.
Skin Examination: Check for skin lesions, such as vesicular rash of herpes zoster (shingles).
Neck Examination: Assess for jugular venous distension (JVD), particularly with inspiration (Kussmaul’s sign), which may indicate right heart failure or pericardial tamponade.
Chest Examination:
- Palpation: Palpate the chest wall to assess for reproducible tenderness, suggesting musculoskeletal pain. Check for crepitus, which may indicate subcutaneous air in pneumothorax or infection.
Heart Auscultation: Listen for abnormal heart sounds, murmurs, or rubs.
Lung Auscultation: Assess breath sounds for abnormalities like wheezing, crackles, or diminished breath sounds, which may indicate asthma, pneumonia, or pneumothorax.
Abdominal Examination: Evaluate for abdominal tenderness, guarding, or rebound tenderness, which can suggest gastrointestinal causes of chest pain.
Extremities Examination: Examine for unilateral swelling, calf tenderness, edema, and presence and equality of peripheral pulses. Unilateral leg swelling and calf pain suggest DVT.

Evaluation of Chest Pain

The evaluation of chest pain should be guided by the initial assessment and suspicion for life-threatening conditions. Many institutions have established protocols for chest pain evaluation. Minimum investigations typically include:

Electrocardiogram (ECG): Obtain an ECG promptly, ideally within 10 minutes of arrival, to assess for ST-segment elevation myocardial infarction (STEMI) and other cardiac abnormalities. Serial ECGs may be necessary to detect evolving changes.
Chest X-ray: To evaluate for pneumonia, pneumothorax, pleural effusion, and mediastinal widening (suggestive of aortic dissection).
Laboratory Tests:
- Complete Blood Count (CBC): To assess for infection (elevated white blood cell count).
- Basic Metabolic Panel (BMP): To assess electrolyte imbalances and renal function.
- Troponin Levels: Cardiac biomarker to detect myocardial injury. Serial troponin levels (e.g., 4 hours apart) are crucial for detecting myocardial infarction.
- Lipase: May be considered if pancreatitis is suspected as a cause of chest pain.
Computed Tomography Pulmonary Angiography (CTPA): If pulmonary embolism (PE) is suspected, CTPA is the preferred imaging modality.
Ventilation-Perfusion (VQ) Scan: Consider VQ scan if CTPA is contraindicated (e.g., contrast allergy, renal insufficiency) for PE evaluation.
Bedside Ultrasound (US): Useful for rapid assessment of pericardial effusion/tamponade and pneumothorax in unstable patients.

Treatment and Management of Chest Pain

Management of chest pain is directed by the underlying etiology. Initial management in the acute setting focuses on stabilizing the patient and addressing life-threatening conditions.

Acute Coronary Syndrome (ACS) Management

Initial steps in managing suspected ACS include:

Cardiac Monitoring: Continuous ECG monitoring.
Intravenous Access (IV): Establish IV access for medication administration.
Aspirin: Administer 162 mg to 325 mg of chewable aspirin immediately, unless contraindicated.
Antiplatelet Therapy: Consider clopidogrel or ticagrelor in addition to aspirin, unless urgent bypass surgery is anticipated.
Pain Management: Address chest pain with analgesics as appropriate (e.g., morphine).
Oxygen Therapy: Administer supplemental oxygen if the patient is hypoxic.
Nitroglycerin: May be used to relieve ischemic chest pain and reduce preload and afterload. Aim for a 10% mean arterial pressure (MAP) reduction in normotensive patients and a 30% MAP reduction in hypertensive patients. Avoid in hypotensive patients and those with inferior ST-elevation MI.
Reperfusion Therapy (for STEMI):
- Percutaneous Coronary Intervention (PCI): Preferred reperfusion strategy. Aim for PCI within 90 minutes of arrival at a PCI-capable center or within 120 minutes if transfer is required.
- Thrombolytics: If PCI is not available within the recommended timeframe, initiate thrombolytic therapy within 30 minutes of arrival.
Management of NSTEMI and Unstable Angina: Patients with non-ST elevation myocardial infarction (NSTEMI) and unstable angina require admission for cardiology consultation and further evaluation, including risk stratification and consideration for invasive management.
Stable Angina: Patients with stable angina may be managed in the outpatient setting with medical therapy and lifestyle modifications.
Observation and Further Workup: Elderly patients and those with comorbidities may require admission for observation and further cardiac workup even if initial evaluation is not definitive for ACS.

Pulmonary Embolism (PE) Management

Anticoagulation: Initiate anticoagulation therapy promptly in patients with confirmed or suspected PE.
Thrombolytics: Consider thrombolytic therapy for hemodynamically unstable patients with massive PE.
CTPA or VQ Scan: CTPA is the preferred confirmatory test for PE. VQ scan can be used if CTPA is contraindicated, but it is less sensitive in patients with underlying lung disease.

Pneumothorax (PTX) Management

Chest Tube Decompression: Tension pneumothorax requires immediate needle decompression followed by chest tube placement. Smaller pneumothoraces may be observed or managed with aspiration or small-bore chest tube, depending on size and clinical stability.

Pericardial Tamponade Management

Fluid Bolus: May be used as a temporizing measure to improve hemodynamics.
Pericardiocentesis: Needle pericardiocentesis or surgical pericardial window is required to relieve pressure and drain fluid from the pericardial sac. Bedside ultrasound guidance is helpful for pericardiocentesis.

Aortic Dissection Management

Blood Pressure Control: Rapidly lower systolic blood pressure to 100-120 mmHg using intravenous beta-blockers (e.g., labetalol, esmolol) to reduce aortic wall stress and prevent propagation of dissection.
Surgical Consultation: Emergent cardiothoracic surgical consultation is essential as surgical repair is often required, especially for ascending aortic dissection. Type B (descending) dissections may be managed medically if uncomplicated.
CT Angiography: CT angiography is the gold standard for diagnosing aortic dissection.

Esophageal Perforation Management

Surgical Consultation: Esophageal perforation is a surgical emergency requiring immediate surgical consultation.
Contrast Esophagram: Contrast esophagram is the best confirmatory test.
Supportive Care: Includes NPO status, intravenous fluids, broad-spectrum antibiotics, and pain management.

Gastroesophageal Reflux Disease (GERD) Management

Antacids: Over-the-counter antacids may provide temporary relief.
GI Cocktail: Viscous lidocaine mixed with Maalox (or Mylanta) may be used for symptomatic relief, but it is not diagnostic and should not delay evaluation for serious conditions like ACS.
Proton Pump Inhibitors (PPIs) or H2 Blockers: Long-term management of GERD typically involves PPIs or H2 receptor antagonists to reduce gastric acid production.

Differential Diagnosis of Chest Pain

The differential diagnosis of chest pain is broad and includes:

Acute Coronary Syndrome (ACS)
Aortic Dissection
Pulmonary Embolism (PE)
Pneumothorax
Pericardial Tamponade/Pericarditis
Esophageal Rupture
Gastroesophageal Reflux Disease (GERD)
Esophageal Spasm
Musculoskeletal Chest Pain (Costochondritis, Muscle Strain)
Pneumonia/Pleuritis
Herpes Zoster (Shingles)
Cervical Radiculopathy
Anxiety/Panic Disorder
Mitral Valve Prolapse
Hypertrophic Cardiomyopathy
Pulmonary Hypertension

Pearls and Other Important Considerations

Aortic Dissection and Stroke: Be aware that aortic dissection can present with stroke symptoms due to involvement of carotid arteries. Consider aortic dissection in the differential diagnosis of stroke, especially in patients with chest pain.
Atypical ACS Presentations: Younger patients and those without traditional risk factors can still experience myocardial infarction. Elderly patients and individuals with diabetes may have nerve damage (neuropathy) leading to atypical presentations of ACS, such as less typical pain or absence of pain. Maintain a high index of suspicion in these populations.
“Rule Out MI” Approach: In any patient presenting with chest pain, the initial approach should be to “rule out MI” and other life-threatening conditions.

Enhancing Healthcare Team Outcomes

The effective management of chest pain requires a collaborative interprofessional team approach. Nurse practitioners, primary care providers, internists, emergency department physicians, and surgeons all play crucial roles in the evaluation and care of patients with chest pain. A thorough medical history is often the key to diagnosis. The primary goal is to identify and not miss life-threatening conditions such as acute MI and aortic dissection. When the cause of chest pain remains uncertain after initial evaluation, referral to a specialist (e.g., cardiologist, pulmonologist, gastroenterologist) is recommended to ensure appropriate diagnosis and management. Patient outcomes in chest pain depend significantly on the underlying cause and the timeliness and effectiveness of treatment. Prompt recognition and management of serious conditions are essential for improving patient outcomes and reducing morbidity and mortality.

Review Questions

(Note: Review questions are typically included in continuing education activities, but are not included in this rewritten article to maintain focus on the core content as per instructions.)

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Disclosure: Ken Johnson declares no relevant financial relationships with ineligible companies.

Disclosure: Sassan Ghassemzadeh declares no relevant financial relationships with ineligible companies.