L28 Flashcards
2 types of HF
HFpEF = systolic dysfxn
HFrEF = diastolic dysfxn
Same clinical presentation: orthopnea, PND, DOE, peripheral edema
What is low EF
Calculate EF
EF = SV/EDV
= amt out / total filling amt
What does systolic vs diastolic dysfxn mean for HF?
Diastolic dysfxn = inadequate LV filling at normal pressures
Systolic dysfxn = inadequate LV ejection
What are 3 reasons you might not be filling LV completely - HFpEF
- LV hypertrophy - excessive muscle means ↓compliance
- CAD –> ischemia = stiffer
- Restrictive cardiomyopathy
What is restrictive cardiomyopathy? How does this look on ECHO?
Tissue invading myocardium that change the muscle properties (compliance)
See bilateral atrial dilation - small ventricles w/ huge atrial
What does ↓LV compliance (filling) lead to? 2 things:
- ↑LV EDP
2. ↓SV
What does ↑LV EDP lead to?
Pulm edema
pEF or rEF - more common in:
- Older pts
- Women
pEF
Compensation for ↓CO w/ HF
- ↑renin - AGT2 - aldosterone = volume expansion
- ↓baroreceptor firing -> ↑sympa tone (↑NE) -> ↑contractility
GOAL = ↑afterload & HR to restore CO
Why do HF pts get peripheral and pulm edema?
Overcompensation with RAAS
The Law of LaPlace says that LV wall stress equals
LV wall stress = (LV radius x LV pressure) / 2x LV thickness
A dilated LV w/ thin walls = high wall stress
- Hypertrophy to ↓that stress
pEF or rEF - treat with med
rEF only!!
Which meds improve survival of rEF pts
BBs
ACE/ARBs
Aldosterone antagonists
Hydralazine-nitrates
Which med improve symptoms of rEF pts
Diuretics
Inotropes
