Cardiac valvular abnormalities Flashcards
Review, but systemic BP is directly related to the product of which two things, and how do those break down?
CO and SVR and CO is HR x SV.
In stenotic valvular lesions, there is a ___ overload state on which cardiac chamber?
pressure overload state on downstream cardiac chamber (LV in Aortic stenosis, LA in mitral stenosis)
IN regurgitant lesions, there is a ____ overload state on which chamber?
Volume overload state on downstream cardiac chamber. LA in Mitral regurg
Afterload: regurgitant vs stenotic lesions:
regurgitatnt: increases in afterload can lead to more regurgitation but a signifcant drop in afterload is awful for stenotic lesions.
Decreased afterload: good for regurgitant because it makes forward flow easier. Not good for stenotic
Aortic stenosis: presence and severity of symptoms are related to ?
related to prognosis of the disease
How is it that pts with AS end up having syncopal episodes?
Higher oxygen requirements during times of exertion lead to vasodilatation, but this decrease in SVR can NOT occur due to fixed output, so hypotension and decreased perfusion of the brain can happen=syncope
Normal aortic valve area:
1.6-2.5 cm^2
Vavle area and gradient in mild AS:
valve area: 1.5-1.0 resulting in minimal elevation in peak gradient to less than 20 mmHg
Valve area and gradient in moderate AS:
1.0-0.8 and peak gradient of greater than 50
Valve area and gradient in severe AS:
Valve area below 0.8 and peak gradients between 50-100 mmHg
What happens to the ventricle with aS:
myocardial hypertrophy leads to decrease in compliance of LV and thereby a decease in passive filling of LV during diastole.
Atrial systole and AS:
In a normal situation, atrial systole provides 20-30% of LV filling volume. these AS patients need this to maintain CO. If a fib develops-bad news
Goal HR of AS patients:
70-90-adequate cardiac output wile maintaining oxygen delivery and consumption
Preload in AS patients:
they need to be have adequate preload, being cautious as too much intravascular volume can tip the balance and place these patients in pulmonary edema
Contracitlity inAS:
Ventriclar performance decreases as a result of hypertrophy to overcome the narrowing of aortic valve