## **Core Concept**
The patient's symptoms of chest pain not associated with exercise and the presence of multiple non-ejection clicks during chest auscultation are suggestive of **Mitral Valve Prolapse (MVP)**, a condition characterized by the prolapse of the mitral valve leaflets into the left atrium during systole. This condition is often associated with **myxomatous degeneration** of the valve.

## **Why the Correct Answer is Right**
The investigation of choice for diagnosing **Mitral Valve Prolapse (MVP)** is **Echocardiography**, specifically **Transesophageal Echocardiography (TEE)** or **Transthoracic Echocardiography (TTE)**. Echocardiography allows for the direct visualization of the mitral valve leaflets and their movement, confirming the prolapse. It also assesses the degree of mitral regurgitation, if any. Given that the description points towards MVP, echocardiography is the most appropriate diagnostic tool.

## **Why Each Wrong Option is Incorrect**
- **Option A:** While **Electrocardiogram (ECG)** can provide information on cardiac rhythm and may show nonspecific changes in MVP, it does not directly visualize the valve or diagnose MVP.
- **Option B:** **Chest X-ray** can show cardiac silhouette changes or signs of pulmonary congestion in advanced cases but does not directly diagnose MVP.
- **Option C:** This option is not provided, but typically, other imaging or diagnostic tests not directly related to cardiac structure visualization would be incorrect.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that **Mitral Valve Prolapse** is often associated with **non-ejection clicks** (mid-systolic clicks) and sometimes a late systolic murmur due to mitral regurgitation. These findings are classic on physical examination. Additionally, MVP is more common in females and can be associated with anxiety and panic disorders.

## **Correct Answer:** . Echocardiography