MHD: Congestive Heart Failure Flashcards Preview

MHD/Pharm Block 4 > MHD: Congestive Heart Failure > Flashcards

Flashcards in MHD: Congestive Heart Failure Deck (19):
1

What are the major determinants of cardiac performance?

Heart rate
Preload
Afterload
Contractility

2

What effect does Ca2+ levels have on contractility

Ca2+ levels are the main determinant of contractility
More calcium, more contractility

3

How is ejection fraction calculated?

(EDV-ESV)/EDV x 100
What percent of the blood in the ventricle gets ejected each beat?

4

Diastolic filling is most closely related to what parameter of cardiac performance?

Diastolic filling is quantified by preload
More filling, increased stretching, increased stroke volume

5

What is the definition of afterload?

Impedance to ejection of blood

6

What are the general causes of congestive heart failure?

Impaired contractility
Increased afterload
Impaired ventricular relaxation/decreased filling

7

What is the difference between HFrEF and HFpEF?

Ejection fraction preservation.
r = reduced EF
p = preserved EF

8

How do SV and EDV change in HFrEF and HFpEF?

HFrEF: decreased SV, increased EDV
HFpEF: decreased SV, decreased EDV

9

Which side of the heart fails more easily?

Right: More compliant than left, very susceptible to acute changes in pulmonary vascular resistance

10

What can cause right sided heart failure?

Cardiac causes: LV failure, mitral stenosis/regurg, acute MI with RV infarct, pulmonic stenosis
Pulmonary parenchymal diseases: COPD, ARDS, fibrosis
Pulmonary vascular diseases: PE, pulmonary HT

11

What are the compensatory mechanisms to maintain cardiac output in CHF?

Frank-starling mechanism
Autonomic NS: baroreceptors
Renal: RAA system
Ventricular remodeling

12

Are compensatory mechanisms beneficial, or pathological?

Yes.
Initially, they help but can ultimately lead to decreased performance

13

Describe the vicious cycle associated with congestive heart failure

Ventricular performance decreases, leading to decreased CO. Decreased CO is compensated for by a variety of mechanisms including increased systemic vascular resistance. This increases afterload on the heart, which further decreases ventricular performance.

14

What is the time-course for ventricular remodeling following MI?

Acute changes occur within seconds
Infarct expansion occurs over hours-weeks
Hypertrophy and dilatation occurs over week-years

15

What is the difference between concentric and eccentric hypertrophy?

Concentric: decreased chamber size due to increased wall thickness
Eccentric: dilated chambers with ~normal wall thickness

16

In relation to CHF, when does remodeling begin?

Months to years earlier

17

What drugs are used to prevent/slow ventricular remodeling?

ACE inhibitors, beta blockers, aldosterone antagonists, hydralazine + nitrates

18

What are the clinical manifestations of left-sided heart failure?

Dyspnea, orthopnea, paroxysmal nocturnal dyspnea, cough and fatigue

19

What are the clinical manifestations of right-sided heart failure?

Peripheral edema
RUQ discomfort