Which one is correct regarding electrocardiograph (ECG)?

Options

A. P-wave represents the electrical excitation of the ventricle
B. QRS complex represents repolarisation of the ventricles
C. T-wave represents repolarisation of the atria
D. by counting the number of QRS complexes one can determine the pulse rate.

Explanation

To determine which statement is correct regarding the electrocardiograph (ECG), let's analyze each option step by step:

1. **Option 1: P wave represents the electrical excitation of the ventricle.**
- This statement is incorrect. The P wave actually represents the electrical excitation (depolarization) of the atria, not the ventricles.

2. **Option 2: QRS complex represents repolarization of the ventricles.**
- This statement is also incorrect. The QRS complex represents the depolarization of the ventricles, which is the electrical excitation of the ventricles, not their repolarization.

3. **Option 3: P wave represents the repolarization of the artery.**
- This statement is incorrect as well. The P wave does not represent repolarization of the arteries; it represents the depolarization of the atria.

4. **Option 4: By counting the number of QRS complexes, one can determine the pulse rate.**
- This statement is correct. The QRS complex corresponds to the heartbeat, and by counting the number of QRS complexes in a specific time period (usually one minute), one can determine the pulse rate or heart rate of an individual.

**Conclusion:**
The correct statement regarding the electrocardiograph (ECG) is: "By counting the number of QRS complexes, one can determine the pulse rate."

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