Mitral Valve Flashcards
MV leaflet directly connected to NCC and LCC of AV
Anterior leaflet via the inter valvular / inter annular fibrosa
Papillary muscle most likely to rupture
Posteromedial papillary muscle to due blood supply from single coronary artery (RCA—>PDA in 70%)
•anterolateral papillary muscle has dual supply from LCX and LAD
Structures that can be damaged during MV repair
LCX coronary artery and the bundle of His due to their anatomical proximity to the MV
Assessment of MV short axis (AP diameter)
ME AV LAX view at end systole ( <= 36 mm) Best view to look for prolapse Assess A2 and P2 scallops Measure vena contracta Highest part of MV annulus
Assessment of MV long axis (commissural / low axis)
ME Commissural view at end systole (<= 46 mm)
Assess P3 / A2 / P1 scallops
Lowest part of the annulus
MV TEE views
ME4C — can’t really tell which leaflets unless probe in hand. Withdraw —> more anterior or advance —> more posterior
**MC — P3 / A2 / P1
ME2C — P3 / A1. Turn probe left / right to determine scallops
**ME LAX — P2 / A2
TG Basal SAX — en face view. Interrogate with color but perpendicular so may identify lesion but unable to quantify severity
TG2C — PM and AL papillary muscle. Turn probe right / left to visualize each.
Causes of MR
Myxomatous degeneration •most common in west Rheumatic •most common in developing nations Ischemia •papillary muscle dysfunction and rupture Cardiomyopathy •dilated, IHSS Endocarditis •hole or lesion Congenital •cleft anterior leaflet with AV canal Connective tissue disease •SLE, RA, Marfan’s
MV leaflet motion / Carpentier classification
Normal — type 1
•central jet due to perforation or annular dilation
Excessive — type 2
•jet away from disease leaflet
•billowing, prolapse, flail
Restrictive — type 3a
•jet towards diseased leaflet
•restricted in systole AND diastole
•rheumatic disease (thickening and fusion)
Restrictive — type 3b •central jet if both leaflets restricted •restricted only during systole •dilated cardiomyopathy or ischemia •ventricular disease instead of valvular disease —> displacement of papillary muscles to outside of heart
Grading of MR
Area jet / Area atria •>40% •challenging to measure due to not seeing whole atrium Vena Contracta** •>7 mm MR jet area** •>10 cm^2 Pulmonary vein flow** •S reversal MR fraction •≥50% Regurgitant volume •≥60 cm^3 Orifice area •≥0.4 cm^2 PISA radius (Vmr=500 cm/s, Alias =40cm/s) •>10mm CWD signal strength •very dense V-wave cutoff •asymmetrical envelope with sharper downslope Eccentric wall hugging jet •Coanda effect = severe
Risk factors for SAM after MV repair
Small non-dilated LV
Small annuloplasty ring
Excessive posterior leaflet tissue causing anterior displacement of the coaptation line
C-sept < 2.5 cm **
AL/PL ratio < 1 **
Excessive anterior leaflet distal to coaptation point
Causes of MS
Rheumatic heart disease •most common cause everywhere •most common in developing nations •strep infection -> M protein mimicry -> acute rheumatic fever -> chronic rheumatic heart dz •leaflets heavily calcified, thick tips, immobile, fused leaflets, commissures not very mobile •significant MR (type 3a) •diastolic doming of anterior leaflet with ‘hockey stick appearance’ *** LA myxoma Severe mitral annular calcification Thrombus formation Parachute MV Congenital Subvalvular ring Cor triatriatum sinister
Calculation of MVA
Planimetry •TG Basal SAX PHT •MVA = 220 / PHT DT •MVA = 759 / DT Continuity Equation •MVA = (Alvot x VTI lvot) / VTI mv PISA •MVA = Qpisa / Vpeak
Severity of MS
Mean pressure gradient
•> 10 mmHg
•problems: overestimates — severe MR, decreased LV compliance, increased HR, increased SV; underestimates — angle of incidence, impaired LV relaxation, decreased SV
PHT
•>220
•problems: severe AI and decreased LV compliance decrease pressure gradient which overestimates MVA and underestimates degree of stenosis
MVA
•<1 cm^2
PISA equation
Q pisa = Q hole
Ahole x Vpeak = Apisa x Valias
Ahole = Apisa x Valias / Vpeak
Ahole = (2pir^2(alpha/180))Valias/Vpeak
Regurgitant volume
Volume in = volume out
Diastolic LV inflow = systolic LV outflow = SV forward + Rvol
RVol MV = SV mv - SV av
SV MV = A mv x VTI mv
SV AV = A av x VTI av —> can use LVOT
*MVA calculated by PHT, DT, PISA, or continuity
Or calculate Rvol by EROA from PISA
Rvol = EROAmrpisa * VTI mr
