Model Answer
0 min readIntroduction
In the absence of patient details, a common and potentially life-threatening medical emergency – Acute Myocardial Infarction (AMI), commonly known as a heart attack – will be considered for diagnosis. AMI occurs due to prolonged ischemia (lack of oxygen) to a part of the myocardium, usually caused by obstruction of a coronary artery. Early and accurate diagnosis is crucial for timely intervention and improved patient outcomes. This answer will outline the diagnostic process, assuming a patient presents with symptoms suggestive of AMI.
Diagnosis: Acute Myocardial Infarction (AMI) – ST-Elevation Myocardial Infarction (STEMI)
The diagnosis is based on the assumption of a patient presenting with classic symptoms and supported by diagnostic findings. The following points justify this diagnosis:
1. Presenting Symptoms:
- Chest Pain: Severe, crushing, or squeezing chest pain, typically radiating to the left arm, jaw, neck, or back. The pain is often described as a pressure sensation.
- Dyspnea: Shortness of breath, often accompanying chest pain, due to reduced cardiac output and pulmonary congestion.
- Diaphoresis: Profuse sweating, a common autonomic response to pain and stress.
- Nausea and Vomiting: Can occur due to vagal stimulation.
- Anxiety and Feeling of Impending Doom: Psychological symptoms associated with severe pain and fear.
2. Clinical Signs:
- Tachycardia: Increased heart rate, a compensatory mechanism to maintain cardiac output.
- Bradycardia: May occur in inferior MI due to vagal stimulation.
- Hypotension: Low blood pressure, indicating reduced cardiac output and potential cardiogenic shock.
- Pale and Cool Skin: Due to peripheral vasoconstriction.
- New Murmur: May indicate papillary muscle dysfunction or ventricular septal rupture (complications of AMI).
3. Diagnostic Investigations:
- Electrocardiogram (ECG): The most crucial initial investigation. STEMI is characterized by ST-segment elevation in contiguous leads. Specific patterns (e.g., anterior, inferior, lateral STEMI) help localize the infarct.
- Cardiac Biomarkers: Blood tests to measure levels of cardiac troponin I or T, and creatine kinase-MB (CK-MB). Elevated levels indicate myocardial damage. Troponin is more specific and sensitive than CK-MB.
- Chest X-ray: To rule out other causes of chest pain, such as pneumothorax or pneumonia, and to assess for pulmonary edema.
- Echocardiogram: To assess ventricular function, wall motion abnormalities, and potential complications like ventricular septal rupture or pericardial effusion.
- Coronary Angiography: The gold standard for diagnosing coronary artery disease and identifying the culprit lesion causing the AMI.
4. Differential Diagnosis:
While AMI is the primary diagnosis, other conditions must be considered:
| Condition | Distinguishing Features |
|---|---|
| Angina Pectoris | Chest pain relieved by rest or nitroglycerin; ECG usually normal. |
| Pericarditis | Sharp, pleuritic chest pain; ECG shows diffuse ST-segment elevation and PR depression. |
| Pulmonary Embolism | Sudden onset of dyspnea and chest pain; ECG may show sinus tachycardia or right heart strain. |
| Aortic Dissection | Sudden, severe tearing chest pain radiating to the back; often associated with hypertension. |
The presence of ST-segment elevation on ECG and elevated cardiac biomarkers strongly supports the diagnosis of STEMI, differentiating it from other conditions.
Conclusion
Based on the hypothetical presentation of a patient with chest pain, dyspnea, diaphoresis, and diagnostic findings of ST-segment elevation on ECG and elevated cardiac biomarkers, the diagnosis of Acute Myocardial Infarction (STEMI) is highly probable. Prompt recognition and initiation of reperfusion therapy (either thrombolysis or percutaneous coronary intervention) are critical to minimize myocardial damage and improve patient survival. Continuous monitoring and management of complications are also essential.
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.