Mitral Regurg 2020 Flashcards
Echo criteria for severe MR
Central jet?
Echo criteria for severe MR
Central jet MR >40% LA or holosystolic eccentric murmur
Echo criteria for severe mitral reguritation : Vena contracta?
Echo criteria for severe mitral reguritation
Vena contracta >= 0.7 cm
Echo criteria for severe mitral reguritation Regurgitant volume?
Echo criteria for severe mitral reguritation
Regurgitant volume > = 60 mL
Echo criteria for severe mitral reguritation regurgitant fraction?
Echo criteria for severe mitral reguritation
Regurgitant fraction > 50%
In patients with asymptomatic, severe primary MR, what LV parameters qualify for mitral intervention
n asymptomatic patients with severe primary MR
LV systolic dysfunction:
- LVEF >= 60%
- LVESD >40 mm
mitral valve surgery is recommended (3–10).
What does it mean when the murmur disappears with acute MR?
it is bad. it is the loss of the pressure differential between the atria and ventricle
is TEE helpful in the evaluation of acute MR?
after myocardial infarction, with hyperdynamic LV function by TTE and no other cause for the deterioration,
TEE can be especially helpful in detecting papillary muscle or chordal rupture or valvular vegetations and annular abscesses that may further accentuate the need for a more urgent surgical approach
vasodilators of choice for acute MR
sodium nitroprusside or nicardipine - helpful in that they are easily titratable
Sodium Nitroprusside Pharmacology
MOA:
Mechanism of Action:
- ferrous iron complexed with nitric oxide (NO) and five cyanide ions.
- SNP reacts with sulfhydryl groups on erythrocytes (as well as albumin and other proteins) to produce nitric oxide (NO).
- Upon binding to vascular smooth muscle, NO triggers intracellular cGMP-mediated activation of protein kinase G –> inactivation of myosin light chains –> VSM relaxation
- In contrast to nitroglycerin, nitroprusside causes a more balanced vasodilatory effect between arteries and veins. Veins slightly more.
Thiocyanate toxicity:
Possible (a rare side effect of sodium nitroprusside) - Thiocyanate helps the conversion of CN
Thiocyanate toxicity rarely occurs, most often in the setting of renal failure and/or prolonged infusions (>72 hours).
The earliest signs of thiocyanate toxicity are frequently tinnitus, abdominal pain, weakness, and variable levels of altered mental status (agitation, disorientation), which can ultimately progress to lethargy, seizures, and coma if not recognized and treated.
Of note, serum thiocyanate levels are only useful if used for confirmation of suspected toxicity in symptomatic patients. Early signs (e.g., tinnitus) may be present at levels above 35 mcg/mL, while symptoms of serious toxicity are expected with serum levels >100 mcg/mL
which CCB are the DHP ?
those ending in “-dpine”
For patients with chronic primary
mitral regurgitation, when is TEE indicated?
In patients with primary MR, when TTE provides insufficient or discordant information, TEE is indicated for evaluation of the:
- severity of MR
- mechanism of MR
- status of LV function
Likely cause of MR in younger vs older adults?
Younger populations:
myxomatous degeneration with gross redundancy of both anterior and posterior leaflets and the chordal apparatus (Barlow’s valve).
- A subset of these patients will present with ventricular arrhythmias, mitral annular disjunction, and LV dilation.
Older populations:
fibroelastic deficiency disease, in which lack of connective tissue leads to chordal rupture.
Impact of favorable loading conditions on LV and performance in the setting of MR?
Favorable loading conditions in MR:
- increase LVEF , but:
- do not affect the extent of shortening.
therefore: a “normal” LVEF in MR is approximately 70%.
The onset of LV dysfunction is inferred when LVEF declines toward 60% or when the LV is
unable to contract to a diameter <40 mm at end-systole
What is a “normal” LVEF in MR?
LVEF and LVESD demonstrating LV dysfunction secondary to MR?
therefore: a “normal” LVEF in MR is approximately 70%.
The onset of LV dysfunction is inferred when LVEF declines toward 60% or when the LV is
unable to contract to a diameter <40 mm at end-systole
