Week 4: Valvular heart disease Flashcards
What are causes of aortic stenosis?
- Bicuspid instead of tricuspid valve. congenital
- Rheumatic: assoc. with mitral involvement, symptoms in 4th and 5th decade
- Degenerative calcific changes: most common form in older patients
Describe the pathophysiology of aortic stenosis.
- Chronic course
- LV compensates via concentric hypertrophy (pressure overload), leading to decreased compliance and increased diastolic LV pressure–>LA hypertrophy
Describe the symptoms of aortic stenosis and the causes behind them.
- Angina
- increased O2 demand due to hypertrophy and increased wall stress
- decreased oxygen supply due to increased diastolic pressure and less coronary perfusion pressure gradient between aorta and myocardium - Syncope
- LV can’t increase CO during exercise b/c stenotic aorta. Exercise also causes vasodilation of peripheral muscle beds
- leads to decreased cerebral perfusion - dyspnea/CHF symptoms
- LV may have contractile dysfxn due to increased after load
- increased LV diastolic vol and pressure leads to increased LA and pulmonary venous pressure–>congestion
Describe the physical findings of aortic stenosis.
- sustained LV impulse from LV hypertrophy
- weakened and delayed arterial upstroke (carotid artery pulsations) -b/c ventricle pushes against resistance, leads to delay
- harsh late systolic ejection murmur
EKG
-LVH, LBBB, secondary ST-T
CXR: cardiomegaly, post-stenotic dilatation, aortic calcification
doppler and cath: pressure gradient between LV and aorta
What is the treatment for aortic stenosis?
- No medical Rx
- surgery, aortic valve replacement
- valvuloplasty/TAVI (transcatheter aortic valve implantation)
- TAVI balloons native valve against wall, puts in stent, and implants prosthetic valve via catheter
Describe etiology of aortic regurgitation.
- valve
-congenital bicuspid
-rheumatic
-endocarditis
-myxomatous degeneration - Aortic root
-marfans
-Erdheim’s medial necrosis
-Ankylosing spondylitis
-syphilis
ACUTE ETIOLOGY
-infectious endocarditis
-traumatic rupture
-dehiscence of prosthetic valve
-dissecting aneurysm
Describe pathophysiology of aortic regurgitation.
ACUTE: surgical emergency
-LV normal, volume load increases LV diastolic pressure, transmitted to LA and Pulm circulation, leading to edema and dyspnea
CHRONIC
-regurg occurs during diastole, LV must pump regurg vol+normal volume
-LV adapts to volume and pressure overload–>eccentric hypertrophy
-LV dilation leads to increased compliance
-drop in aortic diastolic pressure since LV accommodates larger regurg vol–>widened pulse pressure
-drop in aortic diastolic press also leads to decreased coronary artery perfusion pressure
-can eventually develop systolic dysfxn/heart failure
What are symptoms of chronic aortic regurgitation?
- pounding pulse-wide pulse pressure with systolic hypertension from increased stroke volume and decreased aortic diastolic press
- orthopnea, PND from volume overloaded LV
- Angina/chest discomfort from inadequate coronary perfusion
What are physical findings of chronic aortic regurg?
-bounding pulses (increased aortic pulse pressure)
-increased LV stroke volume (impulse)
EKG: LVH, LBBB
CXR: cardiomegaly, apex laterally and downward displaced
Echo-doppler: aortic valve and root morphology and dimensions, regurg area, vena contracta, etc…
What are treatments for chronic aortic regurg?
- medical: asymptomatic patients with preserved LV fxn may benefit from after load reduction via nifedipine
- Surgery: timing is key issues for aortic valve repair/replacement
Describe etiology for mitral stenosis.
-sequelae of rheumatic fever: most common cause, 90% of cases
-rare causes: congenital, myxoma, large vegetations, massive mitral annulus calcification
ACUTE
-endocarditis, chordal tear, papillary muscle rupture, ischemia or infarct.
Describe the pathophysiology of mitral stenosis.
- emptying of LA to LV is impeded. Results in increased LA pressure
- high LA pressure transmitted to pulm circulation–>congestion
- becomes significant when valve area leads than 2cm2
- reactive pulmonary HTN in severe cases can lead to right heart failure
Describe the symptoms of mitral stenosis.
-dyspnea
-orthopnea
-decreased exercise capacity
(from pulmonary HTN)
-palpitations
-hemoptysis (dilated bronchial veins, rupture, not common)
COMMONLY found in pregnant women who were previously asymptomatic
Describe physical findings/signs of mitral stenosis.
-Loud S1 (mitral valve closure, high pressure gradient forces valve leaflets widely separate during diastole)
-opening snap - after S2- sudden tensing of chord tendinae and stenotic valves)
-RV lift, Loud P2 (w/ pulm HTN)
-diastolic rumble/murmur -turbulent flow
-atrial fib -commonly developed
EKG: LAE, RVH, Afib
CXR: LAE, double contour R lower border, widening of carina, L atrial appendage prominent main pulm artery, RVE, pulm venous congestion
-doppler: fish mouth appearance, two leaflets stuck together
Describe treatment for mitral stenosis.
- Medical: slow rate, anti coagulate with Afib, SBE antibiotic prophylaxis
- valvuloplasty
- surgery
