24 HF Basics
- pump draining water from tank being filled with water from pipe
- if pump is working, pumping water out, level of water in tank should be low
- pump starts to fail, less water out
- water level rises
- pump really failed
- tank completely filled, overflow
- chambers fail, blood left behind
- blood exert pressure on wall of heart chamber
- LV systolic pressure can be low in some heart failure
- LVEDP: always high, hallmark of LHF
- top arrow: peak, systolic pressure, may be high or low
- bottom arrow: diastolic pressure, always high
- systolic HF: less blood pumped out, more left behind
- diastolic HF: stiff ventricle, higher pressure
- closes MV at earlier point in time before LA empties, rise in LA pressure, LA begins to fail
- then, pulmonary capillary pressure rises, classic symptoms
- pulmonary capillary, Pc, hydrostatic pressure drives water out into interstitium
- LA pressure = 5, pulmonary capillary pressure also 5
- if LA P increase to 20 in heart failure, hydrostatic pressure in lung also becomes 20
- increase driving force to push fluid out = pulmonary edema
- domino effect: LV failure leads to high pressure in venous system, JVD and edema
- CO falls, vasoconstrict to maintain perfusion and BP via Ang II and sympathetic
- ECV still down even with high TBW
- not enough to overcome RAAS
- One in a million: milrinone
- Don't phoster disinterest: milrinone inhibits phosphodiesterase
- CAMPaign: milrinone decreases breakdown of cAMP
- Flexing arm: milrinone increases cardiac contractility
- Dilated red donkey ears: milrinone causes arteriolar dilation and decreased afterload. Hypotension SE
- Turn the tide: nesiritide
- BuMP: nesiritide is a synthetic form of brain natriuretic peptide (BNP)
- GruMP: nesiritide increases cGMP in smooth muscle
- Dilated red ears and blue legs: nesiritide causes arteriolar and venous dilation, reducing afterload and preload
- Salty peanut stream: nesiritide causes natriuresis
Symptoms
- sudden wakening in middle of night feeling SOB
- insomnia and sleeping upright with pillows behind
- backward failure: symptoms of blood backing up before ventricles, not symptoms from inability to push blood forward
- RHF in isolation: high pressure only in pulmonary artery, etc.
- cor pulmonale: isolated RHF, normal LH
- forward failure: symptoms when LV not pumping blood forward
- loss of appetite: poor perfusion to gut, weight loss (cardiac cachexia)
- confusion: poor perfusion to brain
- narrow pulse pressure: systolic pressure low
- can have clear CXR in chronic state
- RBC pushed out of capillaries, engulfed by macrophages in lung
- find height of bounce, add 5 to it
- Normal = 6 = 1 + 5
- press on abdomen just below liver
Heart Sounds
- S3 in question: left heart failing, pressure high in LA
- S4: more often in diastolic HF
Diagnosis
- definitive: heart catheter
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