Which of the following segments in ECG represents the end of ventricular systole?

Options

A. Beginning of T-wave
B. End of T-wave
C. S-T segment
D. P-Q segment

Answer

To determine which segment in an ECG represents the end of ventricular systole, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the ECG Components**: The electrocardiogram (ECG) consists of several waves and segments that represent different phases of the heart's electrical activity. The main components include the P wave, QRS complex, and T wave.

2. **Identify the Phases of Heart Activity**:
- **P Wave**: Represents atrial depolarization and contraction (atrial systole).
- **QRS Complex**: Represents ventricular depolarization and contraction (ventricular systole).
- **T Wave**: Represents ventricular repolarization and relaxation (ventricular diastole).

3. **Determine the End of Ventricular Systole**:
- Ventricular systole begins with the QRS complex, where the ventricles contract.
- The end of ventricular systole occurs when the ventricles finish contracting and start to relax, which is indicated by the T wave.

4. **Identify the Segment**:
- The segment that follows the QRS complex and precedes the T wave is known as the **ST segment**. This segment represents the period when the ventricles are fully contracted and before they begin to repolarize.

5. **Conclusion**: Therefore, the ST segment represents the end of ventricular systole.

### Final Answer:
The segment in the ECG that represents the end of ventricular systole is the **ST segment**.

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