Valvular dysfunction Flashcards
Consequences of stenosis
Increased chamber pressure –> increased wall stress
Concentric hypertrophy
Increase in O2 demand
Reduced compliance, proximal pressures rise
Consequences of regurgitation
Increase in preload
Increase in SV
Increase volume –> eccentric hypertrophy
Increased O2 demand
Aortic stenosis etiology
degenerative
bicuspid AV
rheumatic
Aortic stenosis S&S, natural hx
Usually asymptomatic for many years
Systolic ejection murmur (crescendo-decrescendo)
- increase in intensity initially as stenosis progresses
- decrease in later stages as CO diminishes
Echo: abnormal AV physiology, increased peak ejection velocity
ECG: show LVH
Chest X-ray: enlarged aorta, AV calcification
Sx occur late, bad prognosis
- angina
- syncope
- CHF
Management of aortic stenosis
Dx using physical, ECG, CXR and echo
Sx carry a bad prognosis
Surgical/pc valve replacement
Aortic regurgitation etiology
Rheumatic
congenital
traumatic
endocarditis (aortic root)
Clinical course of aortic regurgitation
Usually asymptomatic for many years
First abnormality: diastolic decrescendo murmur
(diastolic murmurs are ALWAYS pathological)
Often aortic systolic murmur (larger SV)
LVH –> displaced apex
Widened pulse pressure, water hammer pulse, nailbed capillary pulsations
Echo: abnormal AV morphology (early sign), regurgitant jet from aorta –> LV
- echo LV internal dismension increased
ECG: LVH
CXR: enlarged Ao, LVH, eventually CHF
Exertional dyspnea
Angina/syncope less common than AS
Prognosis with Sx is poor
Management of aortic regurgitation
b-blockers can help Sx
Moderate-high levels of exercise are safe
Manage systemic HTN aggressively - normal BP may benefit from ACEi
Monitor LV function
Valve replacement
- onset of Sx with exertional dyspnea or low CO –> surgical valve replacement/repair
Acute sudden onset/progression is a surgical emergency
Mitral stenosis etiology
Rheumatic
rarely congenital
LA tumour or thrombus
Clinical course of mitral stenosis
More common in women
Apical murmur with snap
- first presystolic, then accompanied by an early diastolic rumble & eventually heard through diastole
- difficult to detect by untrained ears, but is characteristic and occurs early in disease course
Echo: abnormal MV morphology and reduced area, high transmitral velocity, elevated PA pressure & RV dysfunction
ECG: LAH, RAH (eventually)
CXR: LAH, MV calcification, pulmonary venous redistribution, RV enlargement, pulmonary congestion
First symptom: exertional dyspnea
- may be brought on by pregnancy when CO increases
Rales, JVD and edema may develop
Development of arrhythmias –> can increase LA pressure & fall in CO (atrial thrombus may form)
Management of mitral stenosis
Progresses faster than AS
- may be necessary to relieve dyspnea before RVF and pulmonary congestion
Surgical repair/replacement necessary, sometimes as initial management
Medical management only as adjunct to above
- anticoagulation required for AF or previous stroke/peripheral embolus
Mitral regurgitation etiology
Myxomatous degeneration prolapse LV dysfunction and enlargement rheumatic disrupted chordae tendinae/papillary muscle apparatus annular calcification endocarditis hypertrophic cardiomyopathy
Clinical course of mitral regurgitation
Gradual development = usually asymptomatic
Pansystolic murmur at apex and radiation to axilla
ECHO: abnormal MV, increased LA dimension, increased L internal dimension, MV regurgitant jet
ECG: LAH and LVH
CXR: LA and LV enlargement, may show RV enlargement and pulmonary redistribution/congestion at later points
Most prominent sx = dyspnea, first on exertion then at rest
Arrhythmia/pregnancy may bring on sx, but impact less dramatic than MS
Management of mitral regurgitation
Eventually need surgical repair/replacement
(surgery pre-onset of sx –> better outcome)
Medical management of tachycardia & CHF important but only as adjunctive therapy
