Okay, let's tackle this question. The patient is a 23-year-old male with chest pain and palpitations after drinking energy drinks. He has a family history of myocardial infarction at 60. The ECG shows sinus tachycardia, no ST changes, and normal labs including troponin and D-dimer.

First, the core concept here is likely about evaluating chest pain in a young patient with no significant risk factors but a family history of MI. Energy drinks are high in caffeine and other stimulants, which can cause tachycardia and chest discomfort. Since the ECG is normal and labs are negative, acute coronary syndrome is less likely, but maybe he's experiencing a panic attack or anxiety due to stress. However, the family history might make one consider a possible genetic component like hypertrophic cardiomyopathy or aortic dissection, but the normal BP and physical exam argue against that.

The correct answer would probably be a step that rules out serious conditions. Since troponin and D-dimer are negative, maybe a stress test or echocardiogram is next. But wait, the options aren't listed here. Common next steps include ECHO to check for structural heart issues, especially given the family history. Alternatively, if the chest pain is due to caffeine, maybe just observation. But the family history of MI at 60 isn't a strong risk factor for him yet. So, the next step might be an echocardiogram to rule out hypertrophic cardiomyopathy or other structural issues.

Wait, but the options aren't provided. The correct answer in similar cases is often an echocardiogram. Let me think again. The patient's age, normal labs, and negative troponin suggest ruling out structural issues. So, the next step would be an ECHO to check for hypertrophic cardiomyopathy or other structural abnormalities. The family history of MI isn't as relevant here unless there's a genetic condition. Alternatively, maybe a stress test, but in a young patient with acute symptoms, ECHO is more immediate.

So the next step is likely an echocardiogram. Therefore, the correct answer would be an echocardiogram. The other options might include unnecessary tests like a CT scan, which isn't needed here, or maybe a cardiac MRI, but ECHO is more standard. The key is to rule out structural heart disease given the family history and symptoms.

**Core Concept**
This case tests the evaluation of acute chest pain in a young patient with no significant risk factors but a family history of coronary artery disease. Energy drink consumption can induce sinus tachycardia and chest discomfort due to high caffeine and stimulant content. The absence of ST changes, normal troponin, and D-dimer rule out acute coronary syndrome or pulmonary embolism.

**Why the Correct Answer is Right**
The next step should focus on ruling out structural heart disease, especially given the family history of myocardial infarction. An **echocardiogram** is indicated to assess for conditions like hypertrophic cardiomyopathy (a hereditary condition) or other structural abnormalities that could explain the symptoms. Energy drink-induced tachycardia is often benign and self-limiting, but structural causes must be excluded in this context.

**Why Each Wrong Option is Incorrect**
**Option A:** *CT coronary angi

✓ Correct Answer: D. No fuher investigation is required