heart failure Flashcards
Heart failure is the
inability of the heart to pump blood forward at a sufficient rate to meet the metabolic demands of the body (forward failure), or the ability to do so only if the cardiac filling pressures are abnormally high (backward failure)
HR is a
syndrome describing a constellation of signs and symptoms caused by many possible abnormalities of heart function
Poor FORWARD blood flow is a
- key requirement of HF
2. LOW FLOW (↓ cardiac output)
BACKWARD buildup of pressure
- is almost always present as well
- CONGESTION (↑ filling pressures)
- Typically a response to low flow
____ determines dysfunction
function
dysfunction: Displacement pumps
- Squeeze (contraction)
- Fill (relaxation)
- Failure of either systole or
- diastole causes HF
dysfunction: 2x pumps
left and right in series
Left, right, or both can fail
dysfunction: Coordinated by an
- electrical system
2. Too slow, too fast, asynchronous … all ↓ efficiency
dysfunction: Directed by
- 4x valves
2. Regurgitation (backflow) or stenosis (resistance) stress heart
dysfunction: Supplied by
- coronaries
- Regurgitation (backflow) or
- stenosis (resistance) stress heart
dysfunction: Encased in
- pericardium
- Regurgitation (backflow) or
- stenosis (resistance) stress heart
key mediators of blood flow
- intropy
- preload
- afterload
- stroke volume
- heart rate
- cardiac outpuut
Ventricular output increases in relation to
greater filling
Inotropy =
contractility
The more the LV is filled, the more it
will contract