factors affecting cardiac output notes | All India Ayush

CARDIAC OUTPUT & VENOUS RETURN

 Cardiac output is the quantity of blood pumped into aorta each minute by heart

 Venous return is the quantity of blood flowing from veins into right atrium each minute

 These both factors are essential in circulation

 Cardiac output is calculated as :

 CO= stroke volume X heart rate

 ( Eg: 70ml * 70= 4900ml)

Where stroke volume is the volume of blood pumped from each ventricle in each beat

Normal value

 Average cardiac output at rest:

A) men- 5.6 L/minute

B) women- 4.9 L/minute

Thus, Average cardiac output for resting adult- 5L/minute

Factors regulating cardiac output

 A) venous return - Cardiac output is directly proportional to venous return

 B) peripheral resistance -cardiac output varies inversely to changes in peripheral resistance