what is preload and afterload

11:51

13:05

11:22

2:35

1:47

3:12

2:04

2:33

5:56

7:40

10:23

9:09

5:21

5:35

2:10

1:22

2:53

42:21

3:03

2:33

4:23

5:03

2:35

3:16

3:55

3:41

2:57

3:10

5:19

18:48

3:51

15:23

3:40

8:33

1:53

13:14

1:30

2:07

4:31

8:56