Which of the following hormones will lead to increase in number of QRS complexes in an ECG in a minute?

Options

A. Adrenaline
B. Acetylcholine
C. Nor adrenaline
D. Both (1) & (3)

Answer

To solve the question regarding which hormones lead to an increase in the number of QRS complexes in an ECG in a minute, we can follow these steps:

### Step 1: Understand the ECG and QRS Complex
- The electrocardiogram (ECG) records the electrical activity of the heart. The QRS complex specifically represents the depolarization of the ventricles, which is associated with ventricular contraction (systole).

**Hint:** Remember that the QRS complex is crucial for understanding heart contractions and is influenced by various hormones.

### Step 2: Identify the Hormones
- The question presents several hormones as options. We need to analyze how each hormone affects heart rate and consequently the QRS complexes.

### Step 3: Analyze Each Hormone
1. **Adrenaline (Epinephrine)**:
- This hormone is known to increase heart rate and cardiac output. An increase in heart rate will lead to more frequent QRS complexes on the ECG.

**Hint:** Think about the fight-or-flight response; adrenaline prepares the body for rapid action.

2. **Acetylcholine**:
- This neurotransmitter is released from the parasympathetic nervous system and generally decreases heart rate. Therefore, it would not lead to an increase in QRS complexes.

**Hint:** Consider how the parasympathetic system counteracts the sympathetic system.

3. **Non-Adrenaline (Norepinephrine)**:
- Similar to adrenaline, norepinephrine also increases heart rate and cardiac output, which would lead to an increase in QRS complexes.

**Hint:** This hormone is also associated with the body's stress response, similar to adrenaline.

### Step 4: Evaluate the Options
- The options provided include:
1. Adrenaline
2. Acetylcholine
3. Non-Adrenaline
4. Both Adrenaline and Non-Adrenaline

- From our analysis:
- Adrenaline increases QRS complexes.
- Acetylcholine decreases heart rate, thus not increasing QRS complexes.
- Non-Adrenaline increases QRS complexes.

### Step 5: Conclusion
- The correct answer is option 4: "Both Adrenaline and Non-Adrenaline" as both hormones lead to an increase in the number of QRS complexes in an ECG in a minute.

**Final Answer:** Option 4 (Both Adrenaline and Non-Adrenaline).