Model Answer
0 min readIntroduction
Differential diagnosis is a systematic method used by physicians to distinguish between diseases or conditions that present with similar signs and symptoms. It involves creating a list of possible diagnoses, then systematically ruling out possibilities until the most likely diagnosis is reached. Accurate differential diagnosis is crucial for effective patient management, guiding appropriate investigations, and initiating timely treatment. Given the broad nature of the question, we will focus on acute chest pain as a presenting complaint and provide a differential diagnosis accordingly.
Differential Diagnosis: Acute Chest Pain
Acute chest pain is a common presenting complaint with a wide range of potential causes, varying in severity from benign to life-threatening. The following are five important differential diagnoses, each with five key diagnostic features:
1. Acute Myocardial Infarction (AMI) – Heart Attack
- Severe, crushing chest pain: Often described as a pressure or tightness, radiating to the left arm, jaw, or back.
- Elevated Cardiac Biomarkers: Troponin I or T levels are significantly elevated in the blood.
- Electrocardiogram (ECG) Changes: ST-segment elevation or depression, T-wave inversion, or pathological Q waves.
- History of Cardiovascular Risk Factors: Hypertension, hyperlipidemia, diabetes, smoking, family history of heart disease.
- Hemodynamic Instability: Hypotension, bradycardia, or arrhythmias may be present.
2. Angina Pectoris – Stable or Unstable
- Chest Pain on Exertion: Typically relieved by rest or nitroglycerin (stable angina).
- ECG Changes during Pain: May show ST-segment depression or T-wave inversion during an episode.
- Normal Cardiac Biomarkers: Troponin levels remain within normal limits.
- Predictable Pattern: Pain occurs with a similar level of exertion.
- Risk Factors Similar to AMI: Hypertension, hyperlipidemia, diabetes, smoking.
3. Pulmonary Embolism (PE)
- Sudden Onset of Sharp Chest Pain: Often pleuritic (worsened by breathing).
- Dyspnea (Shortness of Breath): Frequently accompanies chest pain.
- Tachypnea (Rapid Breathing): Increased respiratory rate.
- Hypoxia (Low Blood Oxygen): Measured by pulse oximetry.
- D-dimer Elevation: A blood test that indicates the presence of a blood clot.
4. Pneumothorax – Collapsed Lung
- Sudden Onset of Sharp, Pleuretic Chest Pain: Often unilateral (on one side).
- Decreased Breath Sounds: On auscultation (listening with a stethoscope) on the affected side.
- Hyperresonance to Percussion: A hollow sound when tapping on the chest.
- Chest X-ray Findings: Shows a visible pleural line and lung collapse.
- Dyspnea: May be present, depending on the size of the pneumothorax.
5. Esophageal Spasm/Gastroesophageal Reflux Disease (GERD)
- Burning Chest Pain: Often described as heartburn.
- Pain Worsened by Lying Down or Eating: Aggravated by certain foods or positions.
- Relief with Antacids: Symptoms improve with acid-reducing medications.
- Regurgitation: Backflow of stomach contents into the esophagus.
- Normal Cardiac Biomarkers and ECG: Rules out cardiac causes.
| Diagnosis | Key Diagnostic Feature 1 | Key Diagnostic Feature 2 | Key Diagnostic Feature 3 | Key Diagnostic Feature 4 | Key Diagnostic Feature 5 |
|---|---|---|---|---|---|
| AMI | Crushing chest pain | Elevated Troponin | ECG changes | Cardiovascular risk factors | Hemodynamic instability |
| Angina | Exertional chest pain | ECG changes during pain | Normal Troponin | Predictable pattern | Cardiovascular risk factors |
| PE | Sudden, sharp chest pain | Dyspnea | Tachypnea | Hypoxia | Elevated D-dimer |
| Pneumothorax | Sudden, pleuritic pain | Decreased breath sounds | Hyperresonance | Chest X-ray findings | Dyspnea |
| GERD/Esophageal Spasm | Burning chest pain | Worsened by lying down | Relief with antacids | Regurgitation | Normal cardiac tests |
Conclusion
Accurate differential diagnosis of acute chest pain requires a thorough history, physical examination, and appropriate investigations. While the above list provides a framework, clinical judgment and consideration of individual patient factors are paramount. Prompt and accurate diagnosis is essential to initiate appropriate treatment and improve patient outcomes. The increasing prevalence of cardiovascular disease and other conditions causing chest pain necessitates a high index of suspicion and a systematic approach to evaluation.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.