Chapter 51 - Mechanisms of heart failure

Question 1

Definition of 1) heart failure, 2) congestive hear failure

Answer 1

1) heart failure: inability of the heart to adequately meet the metabolic demands of the peripheral tissue
2) congestive heart failure: these demands can only be met by increasing venous filling pressure- pulmonary or peripheral edema, pleural effusion, ascites

Question 2

What are the mechanisms responsible for heart failure?

Answer 2

Interaction between kidney and heart
Activation of RAAS, SNS
Maldaptive compensatory responses (cardiac remodeling and hypertrophy)

Question 3

Explain RAAS activation

Answer 3

RAAS is activated secondary to decreased renal blood flow and decreased tubular Na and Cl concentration as sensed by macula densa. JX cells release Renin-AG1-AG2. ACE converts AG1 to AG2 within pulmonary vasculature.

Question 4

What are the options to suppress RAAS?

Answer 4

1. ACEi
2. Aldosterone antagonist (spironolactone)
3. AG2-receptor blocker
4. Direct renin inhibitor

Question 5

What is Natriuretic peptide’s action?

Answer 5

elicit vasodilation and fluid and sodium excretion (cardioprotective)

Question 6

T/F: In chornic heart failure, despite increased circulating concentration of the natriuretic peptide, there is a net retention of fluid and sodium due to natriuretic peptide receptor downregulation

Answer 6

True

Question 7

What are the disease that are commonly associated with eccentric hypertrophy?

Answer 7

DCM, MMVD, PDA

Question 8

What are the disease that are commonly associated with concentric hypertrophy?

Answer 8

HCM, SAS, pulmonary hypertension