Lecture 26

Question 1

1. failure of heart to pump adequate blood to satisfy body’s needs
2. certain conditions or diseases lead to a decrease in CO
3. can involve the right ventricle, left ventricle, or both (with time, failure of one ventricle leads to failure of the other)

Answer 1

heart failure

Question 2

dysfunctional mechanical pumping (decreased contractility)

Answer 2

systolic heart failure

Question 3

most often caused from coronary artery disease which reduces coronary blood flow to heart leading to hypoxia and impaired contractility → ↓SV → ↑ESV → ↑EDV/preload → with a chronic increase in EDV, the ventricle remodels by dilating → ↓force development→ ↓SV → ↓CO

Answer 3

systolic heart failure

Question 4

reduced cardiac output and ejection fraction

Answer 4

systolic heart failure

Question 5

inadequate relaxation and reduced filling

Answer 5

diastolic heart failure

Question 6

Most often caused from hypertension → ↑ afterload → stimulation of ventricular hypertrophy → ↑ stiffness (↓ compliance) → ↓filling → ↓EDV → ↓SV → ↓CO

Answer 6

diastolic heart failure

Question 7

reduced cardiac output, but ejection fraction may be near normal; this reduced EF is useful only as an indicator of systolic failure

Answer 7

diastolic heart failure

Question 8

compensation of HF due to activation of SNS and RAAS causes ____________

Answer 8

progressive weakening of the heart

Question 9

how does long term activation of the SNS and RAAS contribute to weakening of the heart?

Answer 9

SNS and RAAS ultimately increase the work of the heart which puts a strain on the heart muscle. if the SNS and RAAS increase the oxygen demand of the heart muscle, it has to work harder to deliver that oxygen or the muscle will become hypoxic and hypoxia will cause weakening

Question 10

1. tachycardia (increases O2 consumption
2. increases contractility (increases O2 consumption)
3. vasconstriction (increases afterload, which increases O2 consumption)
4. chronic norepinephrine exposure is toxic to myocardial cells (causes apoptosis)
5. increases risk of arrhythmias which can decrease CO

Answer 10

effects of SNS

Question 11

1. vasoconstriction (increases afterload)
2. stimulates renal sodium and water reabsorption (increases blood volume and preload)
3. stimulates SNS
4. stimulates ventricular remodeling (which causes dysfunction)

Answer 11

effects of RAAS: Ang II

Question 12

1. stimulates renal sodium and water reabsorption (increases blood volume and preload)
2. stimulates interstitial cardiac fibrosis (causing stiffness and dysfunction)
3. increases risk for arrhythmias

Answer 12

effects of RAAS: aldosterone

Question 13

other hormones also contribute to HF, such as ____

Answer 13

ADH

Question 14

loss of cardiac reserve

Answer 14

decompensation

Question 15

compensation can occur for several years in attempt to main an adequate CO the best it can. but as the heart progressively weakens over time, the CO eventually decreases to an inadequate level; the SNS and RAAS can no longer compensate. this is called the ____________ stage

Answer 15

decompensation

Question 16

1. tachycardia
2. decreased cardiac reserve and decreased exercise tolerance
3. shortness of breath
4. peripheral and/or pulmonary edema
5. cardiomegaly (dilation of heart)

Answer 16

signs and symptoms of HF

Question 17

treatment strategies-depends on the stage of dieease

Answer 17

1. Beta blockers
2. ACE inhibitors
3. ARBs
4. Aldosterone antagonists
5. Diuretics
6. decrease salt and water intake

Question 18

inhibit actions of SNS

Answer 18

Beta blockers

Question 19

Inhibit actions of RAAS

Answer 19

1. ACE inhibitors
2. ARBs
3. Aldosterone antagonists

Question 20

increased afterload causes:

Answer 20

hypertrophy

Question 21

why does pathological hypertrophy cause HF?

Answer 21

decreases filling

Question 22

during what phase of the cardiac cycle is the fourth heart sound heard?

Answer 22

atrial contraction

Question 23

what effect to vasodilator drugs tend to have to have on afterload?

Answer 23

decrease it