To obtain a standard ECG, a patient is connected to the machine by three electrodes

Options

A. One to each wrist and to the left ankle
B. One of each ankle and to the left wrist
C. One to each wrist and to the left chest region
D. One to each ankle and to the left chest region

Answer

To solve the question regarding the placement of electrodes for obtaining a standard ECG, we will follow these steps:

### Step-by-Step Solution:

1. **Understand the Purpose of an ECG**:
- An electrocardiogram (ECG) is a graphical representation of the electrical activity of the heart. It helps in diagnosing various heart conditions by recording the electrical signals produced by the heart as it beats.

2. **Identify the Required Number of Electrodes**:
- A standard ECG requires three electrodes to be connected to the patient. These electrodes are placed at specific locations on the body to accurately capture the heart's electrical activity.

3. **Consider the Options Provided**:
- The question provides four options for electrode placement:
- A) One to each wrist and a left ankle
- B) One to each ankle and to a left wrist
- C) One to each wrist and to a left chest region
- D) One to each ankle and to a left chest region

4. **Determine the Best Placement for Electrodes**:
- The ideal placement of electrodes should minimize interference from skeletal muscle action potentials. This is crucial for obtaining a clear and accurate ECG reading.
- The best placement is to connect one electrode to each wrist and one to the left ankle. This configuration helps in avoiding interference from skeletal muscle activity, which is more pronounced in the chest area.

5. **Select the Correct Answer**:
- Based on the analysis, the correct answer is **A) One to each wrist and a left ankle**.

### Final Answer:
The correct placement of electrodes for obtaining a standard ECG is **one to each wrist and a left ankle** (Option A).