Why does the first heart sound occur after the QRS complex?

Related questions

1. How do you calculate QRS duration?
2. What causes T wave abnormality?
3. What is a normal QRS?
4. What are the 3 stages of the cardiac cycle?
5. Which occurs first after the QRS complex occurs?
6. What are the stages of cardiac cycle?
7. What is the QRS complex on an ECG?
8. What does high take off on ECG mean?
9. Why is there a time delay between the QRS complex and peak blood flow?

Tags

1. #immediately
2. #sound
3. #backflow
4. #contraction
5. #close
6. #cycle
7. #makes
8. #heart
9. #first
10. #occur
11. #after
12. #complex
13. #valves
14. #systole
15. #directly
16. #ventricular
17. #prevent
18. #explain