Choose the correct statement

Options

A. The T-wave in an ECG represents excitation of ventricles
B. The sum of P and T waves in a given time period can determine the heart beat rate of an individual
C. The end of the P-wave marks the end of the systole
D. In a standard ECG a person is connected to the machine with three electrical leads.

Answer

To solve the question of choosing the correct statement regarding ECG (electrocardiogram), we will analyze each option step by step.

### Step-by-Step Solution:

1. **Analyze Option 1**:
- Statement: "T wave in an ECG represents excitation of ventricles."
- Explanation: The T wave actually represents the repolarization of the ventricles, not their excitation. Therefore, this statement is **incorrect**.

2. **Analyze Option 2**:
- Statement: "The sum of P and T wave in a given time period can determine the heartbeat rate of an individual."
- Explanation: The heartbeat rate is determined by counting the number of QRS complexes in a given time period, not by the sum of the P and T waves. Thus, this statement is also **incorrect**.

3. **Analyze Option 3**:
- Statement: "The end of P wave marks the end of systole."
- Explanation: The end of systole is actually marked by the T wave, not the P wave. Therefore, this statement is **incorrect**.

4. **Analyze Option 4**:
- Statement: "Standard ECG or person is connected to the machine with three electrical leads."
- Explanation: In a standard ECG setup, typically three leads are placed on the body (one on each wrist and one on the left ankle). This statement is **correct**.

### Conclusion:
After analyzing all the options, we find that **Option 4 is the correct statement**.

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