valve disease Flashcards
types of aortic stenosis (3)
Calcific, bicuspid, rheumatic
types of hypertrophy causing valve disease
Concentric hypertrophy –> stenosis (aortic, pulmonic)
Eccentric hypertrophy –> insufficiency/regurgitation (in any of the 4 valves)
Symptoms of Aortic stenosis
- syncope - from ventricular tachycardia, heart block, or vasodilation w/ fixed stroke volume
- angina - from hypertrophy or CAD
- CHF
* * Sx don’t manifest until very late –> rapid progression once start**
* *Risk of sudden death!**
heart sounds/signs of Aortic Stenosis
- systolic murmur (coarse, high-pitched, late peaking)
- S4 (from stiff ventricle)
- small & slow carotid upstroke (compensatory)
Causes of Mitral Stenosis
1 Rheumatic fever
- Mitral annular calcification
- single papillary muscle
Heart valve stenosis wastes energy bc:
Creates:
- pressure gradient
- turbulence
problems (pathophys) of mitral stenosis
- decreased blood flow into L ventricle
–> underfilled LV
–> increased LA & RV pressure (P backs up)
==> pulmonary venous congestion/HTN
** RV failure if pulmonary stenosis!!!
**Danger: risk of thromboemboli from stasis **
Treatment for aortic and mitral stenosis
Aortic: surgical valve replacement right away w/ Sx
Mitral: surgical valve replacement if moderate Sx, or if A-fib.
Regurgitant fraction
measure of amount of regurgitation by a valve.
RF = regurgitant volume/total stroke volume
causes of aortic regurgitation
Chronic:
- Aortic dilatation, bicuspid valve, Rheumatic heart disease.
Acute:
- endocarditis, aortic dissection.
Consequences of stenosis and regurgitation/insufficiency
Stenosis: pressure overload (only chronic)
Regurgitation: volume overload *can be acute OR chronic
pathophysiology of chronic compensated aortic insufficiency
- compensated, so no big changes in P & f(x), can last long time*
1. some backward flow of blood into LV during diastole
(slowly progressing over time)
2. body senses “HTN” so dilates systemic vasculature
3. LV dilates to compensate for increased volume (has high compliance) –> no significant change in LV pressure
4. total stroke volume increases, so no loss of blood volume to systemic circ.
clinical signs of aortic regurgitation
Sx: fatigue, angina, heart pounding
- “Corrigan’s pulse” = rapidly rising, bounding
- S3 (rapid early filling)
- decrescendo diastolic murmur
- quieter sounds if ACUTE AI bc no compensation!**
pathophysiology of DEcompensated Aortic regurgitation
- Loss of LV compliance –> regurgitated volume > LV volume.
- increased diastolic LV pressures –> decreased contractile force
- ejection fraction falls, preload increases
* * not reversible once EF drops**
Pathophysiology of Acute Aortic insufficiency
Normal heart, w/ acute increase in diastolic pressure
–> L heart failure bc can’t maintain EF w/o increasing compliance.
==> major sympathetic response
Treatment for aortic insufficiency
Surgery to replace Aortic valve as soon as get symptoms or find LV dysfunction (may be asymptomatic)
causes of Mitral Regurgitation
Acute: papillary rupture/stretch or chord perforation
Chronic: Rheumatic fever, dilated LV, Myxomatous degeneration
acute vs. chronic Mitral Regurgitation (pathophys.)
Chronic: enlarged V wave, but keeps almost normal LA pressures bc increased compliance & dilation of LA.
Acute: Huge V wave, w/ massively increased LA pressures & pulmonary edema bc cannot handle increased LA volume.
Determining severity of regurgitation
- Compensation –> LA or LV pressures, higher = bad.
- higher BP = more aberrant blood flow*
- Duration of Regurgitation –> slower HR = more time in diastole & more regurgitation.
- Size of regurgitant orifice –> larger opening = more regurg (bad).
changes in chronic compensated Mitral Regurgitation
- Increased compliance –> increased LV volumes => normal diastolic P
- “very” normal EF (normal amt blood leaving LV, but some goes to LA & some goes to systemic circ.)
Chronic decompensated Mitral Regurgitation
- LV compliance drops –> less compensation –> increasing diastolic P
- EDV increases, & ESV even more so –> contractility drops –> EF drops
- same idea w/ acute MR, but normal LV compliance is not enough to compensate acutely ==> HIGH EF!**
Symptoms of Mitral Regurgitation
Acute: pulmonary edema, short decrescendo murmur
Chronic compensated: dyspnea w/ exertion
Chronic DEcompensated: SOB, fatigue
*both chronics: R heart failure, edema, venous distension; holosystolic murmur
signs of mitral valve prolapse
S3 & L displaced, diffuse apical impulse (LV dilation)
Treatment for mitral regurgitation
Surgery #1 to repair valves, #2 replace if can’t repair.
–> depends on degree of Sx, size of regurg., etc.
