Low heart rate

Low heart rate is seen in

a) Fever
b) Infancy
c) Hemorrhage
d) Hypothyroidism
e) Cardiac failure

Answer

a. F
b. F
c. F
d. T
e. F

Discussion

a.

•  Increase body temperature increase firing rate of SA node therefore heart rate increase 

b.

•  Infant has a high heart rate

Age	Beats/ min
< 1 year	110 - 160
2-5 years	95-140
5-12 years	80-120
>12 years	60-100

c.   

• In hemorrhage , total blood volume decreases 
• Venous return decreases 
• Stoke volume decrease 
• Cardiac output decreases 
• Blood pressure decreases 
• Firing rate of baroreceptor decrease 
• Sympathetic discharge to SA node reduce and parasympathetic discharge increases 
• Heart rate increase initially 
• But later in hemorrhage heart decreases

d.

•  Hypothyroidism induces bradycarida and hyperthyroidism induce tachycardia

e. 

• In heart failure cardiac output reduce
• Blood pressure decreases therefore  with hemorrhage heart rate increase