The tallest positive wave in ECG represents

Options

A. atrial depolarization.
B. ventricular depolarization .
C. atrial repolarization .
D. ventricular repolarization.

Answer

To solve the question regarding what the tallest positive wave in an ECG represents, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the ECG Components**:
- An ECG (Electrocardiogram) is a graphical representation of the electrical activity of the heart during the cardiac cycle. It consists of several waves: the P wave, QRS complex, and T wave.

2. **Identify the Waves**:
- **P Wave**: Represents atrial depolarization.
- **QRS Complex**: Represents ventricular depolarization. This is typically the tallest wave in the ECG.
- **T Wave**: Represents ventricular repolarization.

3. **Analyze the Question**:
- The question specifically asks for the tallest positive wave in the ECG.

4. **Determine the Tallest Wave**:
- Among the waves mentioned, the QRS complex is known to be the tallest wave in the ECG. It indicates the depolarization of the ventricles, which is a significant electrical event in the cardiac cycle.

5. **Conclusion**:
- Therefore, the tallest positive wave in an ECG represents **ventricular depolarization**.

### Final Answer:
The tallest positive wave in the ECG represents **ventricular depolarization**.

---