Valve Dysfunction Flashcards
what are some causes of valve dysfunction?
infections (including tooth plaque), congenital deformity (2 leaflets instead of 3, can’t fully close), disease (rheumatic fever)
what are the two classifications of valve dysfunction?
functional (stenosis, insufficient) or anatomical deformity (prolapse, congenital)
why is valve dysfunction a problem?
heart works harder, eventually will hypertrophy leading to decreased ventricle space, walls get thicker, decreased CO
what is stenosis in valve dysfunction?
impedence of forward flow due to incomplete or narrowed opening of valves
what is insufficiency in valve dysfunction?
incomplete closing of valve leading to regurgitation/back flow of blood
what are murmers in valve dysfunction
turbulence of flow heard during auscultations cause by stenosis or regurgitation
how is the severity of valve dysfunction scored?
mild, moderate, severe, or critical based on valve diameter, degree of regurgitation, and calculation of blood flow across valve
what aortic valve area is mild?
> 1.5 cm2
what aortic valve area is moderate?
1.0 - 1.5
what aortic valve area is severe?
< 1.0
what aortic valve area is critical?
< 0.6
what is the pathophysiology of aortic stenosis?
narrowing of valve –> increased afterload –> increased LV systolic pressure and LV volume overload –> LV hypertrophy –> decreased stroke volume and decreased compliance –> systolic function maintained for a while especially @ rest –> eventual systolic and diastolic dysfunction
what causes mitral regurgitation?
damage to papillary muscles from MI, heart gailure, congenital, endocarditis, rheumatic fever(most common cause of mitral regurgitation due to untreated strep)
what is the pathophysiology of chronic mitral regurgitation?
incompetent valve –> increased blood volume in left atrium –> blood can backflow through pulm. veins –> left atrium dilates over time –> reduced atrial pressure –> reduced atrial kick –> reduced LV EDV –> reduced cardiac output
what causes mitral stenosis?
progressive calcium deposits, congenital, rheumatic fever
what is the pathophysiology of mitral stenosis?
narrowed valve –> increased pressure gradient across valve –> reduced ventricular filling w/ increased dependence on atrial kick –> increased LA pressure and pulm. pressures –> LA dilation over time –> reduced LV EDV and cardiac output
what is aortic insufficiency caused by?
weakened valve closure, stiffened leaflets
what is the pathophysiology of aortic regurgitation?
incomplete closure of valve –> backflow of blood from aorta during diastole –> increased LV EDV –> increased preload, larger stroke volume, increased afterload –> LV dilation and hypertrophy –> decreased systolic function and ejection fraction
what are the clinical manifestations of valve dysfunction?
easy fatigue, SOB, dyspnea w/ exertion, exhaustion, sx of HF (dyspnea, fluid back up, edema)
how do you diagnose a valve dysfunction?
auscultation, symptoms, confirmed w/ echocardiography
what are the two main types of echos?
transthoracic (TTE) and transesophageal (TEE)
what does an echocardiography assess?
size of ventricular cavity, functioning of valves, performance of left ventricle, estimates SV and EF
what is a transesophageal echocardiography?
view of heart and mediastinum, camera thru esophagus
what is the first sound (“lub”) in normal heart sounds of the lub dub?
S1 - closure of mitral/tricuspid valves onset of ventricular systole
what is the second sound (“dub”) in normal heart sounds of the lub dub?
S2 - closure of aortic and pulmonary valves at start of ventricular diastole
what are murmurs and the types of murmurs?
abnormal heart sounds
what are the three categories of a murmur?
high rates of flow through normal or abnormal valves, forward flow thru constricted or deformed valve or into dilated vessel/chamber, backward flow thru valve
what are the types of systolic murmurs?
aortic stenosis, pulmonic stenosis, mitral regurgitation, tricuspid regurgitation
what are the types of diastolic murmurs?
aortic/pulmonic regurgitation, mitral/tricuspid stenosis
how do you manage valve dysfunction
control HR, manage HTN, manage fluid volume
how would you surgically manage valve dysfunctions?
percutaneous or surgical – valvuloplasty or valvulotomy for aortic/mitral vlaves. can do valve replacement or repair
what are the types of valves in a valve replacement surgery?
mechanical or tissue
what is a mechanical valve replacement?
metallic or synthetic material, more durable and can last length of patient’s life, requires lifelong anticoagulation, recommended for younger patients
what is a bioprosthetic (tissue) valve replacement?
made from human or animal tissue, lifespan 10-20 years, no lifelong anticoagulation needed, recommended for older patients
