Mark incorrect statement regarding normal ECG

Options

A. Patient is connected to 3 electrical leads (one to each wrist and to the left ankle)
B. 'T' wave represents atrial repolarization
C. Q marks the beginning of ventricular systole
D. R represents ventricular depolarization

Answer

To determine the incorrect statement regarding a normal ECG (electrocardiogram), we need to analyze the components of the ECG and their respective meanings. Here’s a step-by-step breakdown:

### Step 1: Understand the Components of ECG
- The normal ECG consists of three main components: the P wave, the QRS complex, and the T wave.
- **P wave**: Represents atrial depolarization (contraction of the atria).
- **QRS complex**: Represents ventricular depolarization (contraction of the ventricles).
- **T wave**: Represents ventricular repolarization (relaxation of the ventricles).

### Step 2: Analyze Each Statement
- Now, let's evaluate the statements provided in the question:
1. **"Patient is connected to three electrical leads, one each at the wrist and to the left ankle."**
- This statement is correct. Standard ECG leads are often placed on the wrists and ankles.

2. **"P wave represents atrial repolarization."**
- This statement is incorrect. The P wave represents atrial depolarization, not repolarization.

3. **"QRS complex marks the beginning of ventricular systole."**
- This statement is correct. The QRS complex indicates the start of ventricular contraction (systole).

4. **"R represents ventricular depolarization."**
- This statement is correct. The R wave is part of the QRS complex, which represents ventricular depolarization.

### Step 3: Identify the Incorrect Statement
- From the analysis, the incorrect statement is:
- **"P wave represents atrial repolarization."** (This is incorrect; it represents atrial depolarization.)

### Conclusion
- The incorrect statement regarding normal ECG is that the P wave represents atrial repolarization.

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