Vavular Heart Disease
Miscellaneous Information
 Largest heart valve – tricuspid (4cm2
in area)
 Smallest heart valve – ...
 Example:
 If V1 is less than or equal to 1m/s then:
o Change in Pressure = 4(V2)2
o Measure the velocity of blood with ...
o Dx: Aortic stenosis w/ aortic regurgitation.
Aortic Valve Stenosis (AVS)
 Most common cause on western globe occurring ...
o Systemic HTN – central leak w/ focal fibrous thickening.
o Marfan’s Syndrome – taut margins w/ prolapsed cusps (i.e. flo...
 Most common cause in US is prolapse of mitral valve a/w collagen defects.
 2nd
to 4th
most common cause: IHD, RHD, IE
...
 Most common cause in US is prolapse of mitral valve a/w collagen defects.
 2nd
to 4th
most common cause: IHD, RHD, IE
...
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Valvular Heart Disease notes.doc.doc

  1. 1. Vavular Heart Disease Miscellaneous Information  Largest heart valve – tricuspid (4cm2 in area)  Smallest heart valve – aortic (3cm2 in area)  Leaflets/cusps of the aortic valve form the sinus vasalva, the branch point of the coronary arteries.  Left Atrial Pressure (LAP) = 5mmHg; slightly higher than the Left Ventricular Pressure (LVP) during diastole.  4 components to S1 – the 1st component results from closure of the mitral valve  No sounds with opening of the aortic valve; S2 results from closure of the aortic valve.  Systolic murmur with aortic stenosis extends thru the interval b/t S2 and S1 (i.e. early systolic murmur); dissipates when LAP is greater than LVP; occurs later than systolic murmur of mitral stenosis.  Ejection Fraction = (EDV – ESV)/EDV or SV/EDV o Normal value is approximately 55% o Impaired LV systolic function if less than 55%  Ultrasound = Frequency in the magnitude of 106 o For usage in echocardiograms – highly efficient and widely used diagnostic tool. o Used to determine the volume within the heart chambers. o Echo beam, however, is dispersed thru pulmonary tissue; pts w/ lung disease (e.g. COPD) may be difficult to assess using Trans-Thoracic Echocardiogram (TTE). o May use Trans-Esophageal Echocardiogram for pts w/ pulmonary disease; introduced via the esophagus which just posterior to the heart w/o any impending pulmonic tissue. o Both types produce 1D and 2D pictures.  Doppler – sound waves bounce off RBC’s; measurement of Doppler Effect may be used to calculate the velocity (i.e. directional speed) of the blood.  Narrowing of valves result in a higher velocity of blood since the same amount of blood must flow thru; this produces a thrill upon palpation and murmur upon auscultation.
  2. 2.  Example:  If V1 is less than or equal to 1m/s then: o Change in Pressure = 4(V2)2 o Measure the velocity of blood with Doppler, and then calculate the pressure gradient across the valve.  Normal pressure gradients = 4mmHg; 50mmHg is bad and 100mmHg indicates a tight aortic stenosis.  Stenotic valves will have greater pressure gradients.  To calculate LVP, determine BP, then add the magnitude of the pressure gradient to the BP; this equals LVP (non-invasive measurement of LVP).  If blood is flowing in a direction away from the transducer (e.g. thru aortic valve w/ transducer on surface of chest), the signal is deflected downwards (i.e. negative deflection or blue); if blood is flowing towards the transducer, then upward deflection (i.e. positive deflection or yellow).  Example:  Here, velocity = 5m/s; therefore the pressure gradient = 4(5m/s)2 = 100mmHg; indicates some pathology b/c too pressure gradient is too high; normal velocity should be 1m/s which results in a pressure gradient is 4mmHg.  During systole, blood is flowing away from transducer.  During diastole, blood is flowing towards transducer (abnormal); diastolic deflections are not present normally; indicates aortic regurgitation.  Magnitude of the signals indicate the velocity of blood, and, thus, pressure gradients. o The large systolic deflection in this case indicates aortic stenosis due to the finding of a large pressure gradient. V1 V2 P1 P2 EKG: Systole Aortic valve -5m/s +5m/s
  3. 3. o Dx: Aortic stenosis w/ aortic regurgitation. Aortic Valve Stenosis (AVS)  Most common cause on western globe occurring in pts less than 60 y/o is bicuspid aortic valve.  Most common cause occurring in pts greater than 75 y/o is degenerated aortic valves. o Calcification of cusps. o Increased risk of developing atherosclerosis.  Rheumatic aortic valve contains calcification and thickening on the commissure of the valves caused by autoimmune mechanisms.  Thickened valves have difficulty closing and regurgitation can be manifested.  2 methods of ventricular failure: o Systolic failure – ventricle can’t eject blood efficiently; determined by EF. o Diastolic failure – ventricle can’t relax b/c of hypertrophy and fibrosis (i.e. stiff); this results in an increase in diastolic pressure. o Both can cause backup of blood in the pulmonary circulation causing pulmonary hypertension and edema; both may occur with AS  3 major clinical manifestations of AS: o syncope o angina o heart failure  Survival rates dramatically decrease after the onset of severe symptoms; prognosis (from best to worst): angina, syncope, heart failure.  Valves need to be replaced o Tissue valves – no blood thinners post-operatively o Mechanical valves – blood thinners are necessary.  Murmur: diamond shaped, crescendo-decrescendo murmur w/ palpable thrill; auscultated over right 2nd IC space, sternochondral junction. Aortic Valve Regurgitation (AVR)  Causes: o Congenital bicuspid aortic valve – don’t close normally. o Infective Endocarditis valve – bacterial infection w/ vegetation and perforations. o Rheumatic aortic valve – commissural fusion. S1 S2
  4. 4. o Systemic HTN – central leak w/ focal fibrous thickening. o Marfan’s Syndrome – taut margins w/ prolapsed cusps (i.e. floppy cusps).  Murmur: diastolic decrescendo murmur.  Diastolic pressure drops in aortic regurgitation b/c of back flow of blood into the LV from the systemic circulation; this causes an increase in pulse pressure (i.e. wide pulse pressures).  Treated with surgical repair; may need valvular replacement. Mitral Valve Stenosis (MVS)  Caused by RHD  Hardening and thickening of MV; LV is usually normal.  High pressure gradient b/t LA and LV during diastole  Elevated LAP is transmitted retrospectively to the pulmonary circulation resulting in pulmonary HTN with subsequent thickening of pulmonary arteries; this causes elevated pulmonary capillary pressure and edema, and finally, thickening of the RV.  Law of Laplace, T = (P x r)/w; LA dilatation and thickening (hypertrophy) is a response to elevated LAP.  Murmur: Diastolic rumble preceded by opening snap (occurs earlier if severe mitral stenosis since LAP would be higher compared to less severe MS)  Treat w/ beta blockers to lengthen diastole by decreasing HR; % survival higher w/ Sx  Other Tx: o Valvuloplasty – non-invasive TOC for Echo scores of 8 points or less; pts will have same prognosis as if valve was opened by invasive Sx; Echo scores range from 4 – 18, where 4 is good and 18 is bad. Mitral Valve Regurgitation (MVR)  Most common valvular abnormality. S1 S2 S1 S2 S1 Opening snap
  5. 5.  Most common cause in US is prolapse of mitral valve a/w collagen defects.  2nd to 4th most common cause: IHD, RHD, IE  Associated pathophysiology: o Snapping of chordae tendonae o Dilatation of the LV pulls the leaflets apart  Elevation of LAP w/ progressive dilatation; over time LAP drops and becomes normal, but still dilated w/ reduced compliance.  LAP can get up to 100mmHg w/ acute MVR; results in pulmonary HTN and edema.  Clinical manifestations: o Fatigue o Palpitations o R. heart failure o Pulmonary edema  Murmur: holosystolic murmur; S1 and S2 are buried in the murmur and non- detectable. S1 S2 S3
  6. 6.  Most common cause in US is prolapse of mitral valve a/w collagen defects.  2nd to 4th most common cause: IHD, RHD, IE  Associated pathophysiology: o Snapping of chordae tendonae o Dilatation of the LV pulls the leaflets apart  Elevation of LAP w/ progressive dilatation; over time LAP drops and becomes normal, but still dilated w/ reduced compliance.  LAP can get up to 100mmHg w/ acute MVR; results in pulmonary HTN and edema.  Clinical manifestations: o Fatigue o Palpitations o R. heart failure o Pulmonary edema  Murmur: holosystolic murmur; S1 and S2 are buried in the murmur and non- detectable. S1 S2 S3

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