Y&A: 8 Valvular Heart Disease Flashcards
What are the major etiologies of aortic stenosis? Aortic insufficiency?
AS: More commonly acquired (i.e. progressive calcification or rheumatic fever), less commonly bicuspid valves
AI: Acquired (i.e. bacterial endocarditis, rheumatic heart disease); connective tissue disorders
What are the major etiologies of mitral stenosis? Mitral regurgitation?
MS: Almost always rheumatic fever; other less common causes are SLE, carcinoid, congenital defects
MR: Primary leaflet dysfunction (i.e. bacterial endocarditis or connective tissue disorders), Annular dilation (i.e. ventricular dysfunction/dilation), MV prolapse or rupture of papillary muscles, ischemic heart disease
What changes does aortic stenosis have on the chambers of the heart?
LV: LaPlace’s law: wall tension = Pressure * radius / (2 * wall thickness)
Thus, increased pressure = increased wall tension on LV which causes PARALLEL duplication of muscle fibers –> concentric hypertrophy to normalize wall tension (increased wall thickness)
What changes does aortic insufficiency have on the chambers of the heart?
LV: diastolic volume overload –> SERIES duplication of muscle fibers –> eccentric hypertrophy and LV dilation –> can cause MV annular dilation –> MR –> LA dilation
What changes does mitral stenosis have on the chambers of the heart?
LA: elevation in pressures leads to hypertrophy and eventual dilation –> increases risk of A. fib/PACs
LV: pressure and volume underloaded, especially if the patient is no longer in sinus rhythm 2/2 LA dilation
RV: increased PVR (can be permanent) from pulmonary vessel overload
What changes does mitral regurgitation have on the chambers of the heart?
LV: volume overloaded with a volume going to the high-compliance, low pressure LA (versus the low-compliance, high pressure arterial system) –> eccentric hypertrophy
LA: volume overloaded (as above) –> dilation (if sudden –> pulmonary vein engorgement –> RV issues)
