**Core Concept**
The patient's presentation of recurrent syncopal episodes and hypotension suggests an underlying cardiac cause, possibly related to a structural heart defect or an arrhythmia. The key concept here is the association between syncope and a potentially life-threatening cardiac condition.

**Why the Correct Answer is Right**
The patient's symptoms and low blood pressure are concerning for a cardiac cause of syncope. The ECG is crucial in this scenario to identify potential arrhythmias or structural heart defects. Given the patient's age and presentation, a long QT interval on the ECG is a critical finding that can lead to torsades de pointes, a potentially life-threatening arrhythmia. The treatment of choice in this scenario is magnesium sulfate, which can help stabilize the cardiac membrane and prevent further arrhythmias.

**Why Each Wrong Option is Incorrect**
**Option A:** Atropine is used to treat bradycardia, but it's not the first-line treatment for a patient with recurrent syncope and hypotension.
**Option B:** Adenosine is used to treat supraventricular tachycardia, but it's not indicated in this scenario without further evidence of an arrhythmia.
**Option C:** Amiodarone is an anti-arrhythmic medication, but it's not the first-line treatment for a patient with a potentially life-threatening arrhythmia like torsades de pointes.

**Clinical Pearl / High-Yield Fact**
Torsades de pointes can be precipitated by various factors, including electrolyte imbalances, certain medications, and a prolonged QT interval. Remember the acronym "DIL" to identify patients at risk: Drugs, Inherited conditions, and Low potassium levels.

**Correct Answer:** C. Magnesium sulfate.