**Core Concept**
The patient's presentation is indicative of an acute myocardial infarction (AMI), specifically a non-ST-elevation myocardial infarction (NSTEMI) is ruled out due to ST elevation in leads V3-V6, suggesting a left ventricular wall myocardial infarction. Primary percutaneous coronary intervention (PCI) or PTCA is the preferred reperfusion strategy for AMI when available within a timely manner.

**Why the Correct Answer is Right**
The patient's ECG pattern and symptoms are consistent with a large anterior wall myocardial infarction. The primary goal of treatment is to restore blood flow to the affected area of the heart as quickly as possible. PTCA involves the insertion of a catheter into the coronary artery to remove the blockage, thereby re-establishing blood flow to the heart muscle. This is the most effective way to reduce infarct size, preserve cardiac function, and improve survival.

**Why Each Wrong Option is Incorrect**
**Option A:** Streptokinase is a thrombolytic agent that can dissolve blood clots, but it is not as effective as PTCA in restoring blood flow and reducing infarct size. It also carries a higher risk of bleeding complications.
**Option B:** t-PA (tissue plasminogen activator) is another thrombolytic agent that can be used in the treatment of AMI, but it is not as effective as PTCA and carries a similar risk of bleeding complications. Its use is typically reserved for patients who cannot undergo PTCA.
**Option C:** Heparin is an anticoagulant that can be used to prevent further clot formation, but it is not a primary treatment for AMI. It may be used in conjunction with PTCA or thrombolytic therapy to prevent clot formation.

**Clinical Pearl / High-Yield Fact**
When treating a patient with AMI, it is essential to remember that every minute counts, and the sooner PTCA is performed, the better the outcome. The American College of Cardiology and the American Heart Association recommend that PTCA be performed as soon as possible for patients with ST-elevation myocardial infarction.

**✓ Correct Answer: D. PTCA**