Okay, let's tackle this question. The patient is a 25-year-old female with chest pain, sweating, restlessness, dyspnea, and palpitations. The enzyme analysis and X-ray are normal, and she becomes asymptomatic with supportive care. The key here is that the tests are normal, so it's not a cardiac issue like MI.

First, I need to consider possible differentials. Chest pain with normal enzymes and X-ray could point to something like a panic attack or anxiety. Symptoms like sweating, restlessness, and palpitations are common in panic attacks. They can mimic cardiac issues but resolve without specific treatment.

Other options might include conditions like pericarditis, but that usually has specific ECG changes. Costochondritis could cause chest pain but not the other symptoms. Pheochromocytoma could cause episodic symptoms, but that would likely show elevated catecholamines.

The fact that she became asymptomatic with supportive measures suggests it's not a structural issue. Panic attacks often respond to reassurance and calming the patient down.

So the most probable diagnosis here is a panic attack. The other options either present with different test results or require specific treatments. The clinical pearl is to remember that normal cardiac enzymes and X-ray in a young patient with acute symptoms should make you think of anxiety or panic disorder.

**Core Concept**
The clinical presentation of acute chest pain with normal cardiac enzymes and imaging in a young patient suggests a non-cardiac cause, such as panic attack or anxiety disorder. These conditions mimic cardiac symptoms but resolve with reassurance and supportive care.

**Why the Correct Answer is Right**
Panic attacks present with sudden onset of chest discomfort, tachycardia, sweating, and dyspnea due to sympathetic overactivation. The absence of cardiac biomarker elevation or structural abnormalities (normal X-ray) excludes myocardial infarction, pericarditis, or pulmonary embolism. Supportive measures like oxygen, calming techniques, and benzodiazepines alleviate symptoms by reducing sympathetic tone.

**Why Each Wrong Option is Incorrect**
**Option A:** Myocardial infarction is unlikely due to normal enzyme levels and age (<30 years). **Option B:** Pericarditis typically presents with pleuritic chest pain and ECG changes (e.g., diffuse ST elevation). **Option C:** Pheochromocytoma causes episodic hypertension and sweating but requires elevated plasma catecholamines for diagnosis. **Option D:** Costochondritis causes localized chest wall pain exacerbated by movement, not systemic symptoms like sweating or restlessness. **Clinical Pearl / High-Yield Fact** Normal cardiac enzymes and imaging in a young patient with acute chest pain should raise suspicion for panic attack or anxiety disorder. Remember the acronym **HONKERS** for non-cardiac chest pain causes: **H**yperthyroidism, **O**besity, **N**eurocognitive (e.g., panic), **K**idney stones, **E**lectrolyte imbalance, **R**eflux, **E**xertional, **S**pastic colon. Always rule out anxiety first in such cases. **Correct Answer: C. Panic attack**

✓ Correct Answer: A. Panic attack