CV diseases of the arteries - detailed questions from textbook

Question 1

what could cause a decrease in contractility?

Answer 1

• diseases that cause a decrease in myocyte activity

Question 2

what does decreased contractility lead to?

Answer 2

• it leads to decreased CO and thus SV

Question 3

what does decrease SV lead to?

Answer 3

it leads to heart dilation and an increase in LVEDV (preload)

Question 4

what does an increase in preload do?

Answer 4

• it temporarily increases CO
• it then progresses to cause sarcomere dysfunction which further decreases contractility

Question 5

what issue does dilation of the heart cause?

Answer 5

• it stretches the coronary arteries and causes them to narrow
• this narrowing reduces blood flow and further diminishes contractility

Question 6

what does an increase in afterload do?

Answer 6

• it increases the resistance the heart needs to overcome to pump blood
• this causes the ventricles to work harder

Question 7

what does prolonged increases in afterload lead to?

Answer 7

it leads to remodeling and hypertensive and hypertrophic cardiomyopathy

Question 8

what kind of conditions that remodeling and cardiomyopathy create? what do these conditions increase?

Answer 8

• it creates relative ischemic conditions
• these conditions increase the oxygen demand of the heart

Question 9

what do the relative ischemic conditions cause?

Answer 9

• disruption of muscle integrity
• decreased contractility

Question 10

Describe the role of the renin-angiotensin-aldosterone system (RAAS) in heart failure.

Answer 10

• decreased CO results in inadequate renal perfusion
• this activates the RAAS
• the RAAS increases PVR and plasma volume
• this further increases preload and afterload

Question 11

what do baroreceptors in the circulation do?

Answer 11

• they activate the SNS which stimulates vasoconstriction and cause the hypothalamus to produce ADH
• causes a cycle of decreased contractility, and increased preload and afterload

Question 12

what are the two types of left heart failure?

Answer 12

• heart failure with reduced ejection fraction (EF) (systolic)
• heart failure with preserved EF (diastolic)

Question 13

what is diastolic HF characterized by?

Answer 13

• pulmonary congestion

Question 14

what is systolic HF characterized by?

Answer 14

• EF les than 40% and inadequate CO

Question 15

what is right heart failure characterized by?

Answer 15

inability of the right ventricle to pump blood into the circulation

Question 16

if right heart failure is not caused by left heart failure, what could it be caused by?

Answer 16

diffuse pulmonary hypoxic diseases