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 about the tallest positive wave in an ECG, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the ECG Basics**:
- An electrocardiogram (ECG) measures the electrical activity of the heart during the cardiac cycle. It displays this activity as waves.

2. **Identify the Waves in ECG**:
- The main waves in an ECG are the P wave, QRS complex, and T wave.
- Each wave corresponds to different electrical activities in the heart.

3. **Focus on the QRS Complex**:
- The QRS complex is composed of three waves: Q wave, R wave, and S wave.
- Among these, the R wave is typically the tallest and most prominent wave in the ECG.

4. **Determine the Function of the R Wave**:
- The R wave represents the depolarization of the ventricles, which is the process that triggers them to contract and pump blood.

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

### Final Answer:
The tallest positive wave in an ECG represents the **ventricular depolarization**, specifically indicated by the **R wave** of the QRS complex.

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