By counting number of QRS complexes in ECG in a given time period we can determine

Options

A. Cardiac output
B. Stroke volume
C. Heart beat rate
D. Electrical activity of heart

Answer

To determine what can be inferred by counting the number of QRS complexes in an ECG over a specific time period, follow these steps:

### Step-by-Step Solution:

1. **Understanding QRS Complexes**: The QRS complex in an ECG represents the electrical activity associated with the contraction of the ventricles of the heart. Each QRS complex corresponds to one heartbeat.

2. **Counting QRS Complexes**: If we count the number of QRS complexes in a given time period (for example, one minute), we can determine the heart rate.

3. **Calculating Heart Rate**: The heart rate is typically expressed in beats per minute (bpm). For instance, if we count 75 QRS complexes in one minute, the heart rate would be 75 bpm.

4. **Normal Heart Rate Range**: The normal resting heart rate for adults ranges from 60 to 100 bpm. A heart rate of 72-75 bpm is considered normal.

5. **Conclusion**: By counting the QRS complexes, we can conclude the heart rate of an individual. This information is crucial for assessing cardiovascular health.

### Final Answer:
By counting the number of QRS complexes in an ECG in a given time period, we can determine the heart rate (beats per minute).

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