## **Core Concept**
The patient's symptoms of recurrent chest pain and palpitations with a high frequency of ectopic beats (6-7 per minute) not related to exertion, along with low blood pressure (86 mm Hg) and a relatively normal pulse rate (86/min), suggest a cardiac issue that may require immediate attention. The clinical presentation hints towards a possible acute coronary syndrome or a severe arrhythmia but given the context, an investigation that can quickly and accurately assess cardiac function and structure is crucial.

## **Why the Correct Answer is Right**
The correct answer, **Holter Monitoring**, is ideal for this patient because it allows for the continuous monitoring of the heart's rhythm over a 24-hour period. This is particularly useful for capturing intermittent symptoms such as palpitations and for quantifying the frequency of ectopic beats over time. Given that the symptoms vary in duration and severity and are not related to exertion, a Holter monitor can provide valuable information on the heart's rhythm during daily activities, potentially correlating symptoms with specific arrhythmias.

## **Why Each Wrong Option is Incorrect**
- **Option A: Echocardiogram** - While an echocardiogram can provide valuable information on cardiac structure and function, it is not ideal for capturing transient arrhythmias or directly measuring blood pressure. It's more of a snapshot in time rather than a prolonged monitoring tool.
- **Option B: Exercise Stress Test** - This test is less suitable because the symptoms are not related to exertion, which is a key component of the stress test. It might not accurately reflect the patient's condition or provoke the symptoms.
- **Option C: Cardiac Biomarkers** - While useful in diagnosing acute coronary syndromes, cardiac biomarkers may not directly address the issue of palpitations or the frequency of ectopic beats.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that for patients with symptoms suggestive of intermittent arrhythmias (like palpitations and ectopic beats), **Holter monitoring** is a critical diagnostic tool. It can help in diagnosing and managing conditions that are not easily captured with a standard electrocardiogram (ECG) due to their intermittent nature.

## **Correct Answer: C. Holter Monitoring**