Valvular Disease Flashcards
What valves are open in systole?
Aortic & Pulmonic
What valves are open in diastole?
Mitral & Tricuspid
Murmur btwn S1 and S2
Stenosis of AV or PV
Regurg of TV or MV
Path of blood flow through the heart
Superior/Inferior Vena Cava to RA through Tricuspid valve to RV through pulmonic valve to Pulmonary arteries to lungs to Pulmonary veins to LA through the Mitral Valve to LV through Aortic valve to the aorta
Murmur btwn S2 and S1
Regurg of AV or PV
Stenosis of MV or TV
What is the most common arrhythmia produced by valvular disease?
Afib
Patients can have _____ with normal coronaries?
Angina
Due to the inability to meet O2 demand vs. CA stenosis. Ventricles hypertrophy creating further demand ischemia
Stenotic lesions require
suppressing HR to prolong diastole
Regurgitant lesions require
reducing afterload to reduce the regurgitant fraction
Hypertrophy is diagnosed by CXR when
heart size is > 50% of internal width of the thoracic cage
Mechanical valves pros and cons
Last 20-30 years but require anticoagulation
Lab values with mechanical valves
elevated LDH
decreased haptoglobin
increased reticulocytes (increased RBC turnover)
AHA recommendation for first line prevention of bacterial endocarditis
oral and physical hygiene
Specific verbiage on abx endocarditis prophylaxis
Administered NOT to individuals with high cumulative lifetime risk of contracting endocarditis but to pts with highest risk of adverse outcomes if they dvlp endocarditis
heart valve pts
previous hx of endocarditis
congenital heart disease
heart transplant pts
Which valve is bicuspid?
Mitral-
4-6 cm2
Mitral stenosis
rheumatic heart disease - very rare in US
Iatrogenic - heart catheterization
S/S:
DOE, orthopnea, PND from high left atrial pressures
Murmur:
Snap in diastole and rumbling diastolic murmur hart at the apex or left axilla
Diagnosis: ECHO
< 1.0 cm is severe and LAP is > 25 mmHg (also = PHTN)
Pathophys as MS progresses
pulmonary venous pressure rises to counter increased LA pressure
As the orifice narrows, ever-increasing pressure gradient is created which creates transudation fluid in the pulmonary interstitial space and increases work of breathing
Pulmonary edema when pulmonary venous pressure > plasma oncotic pressure
afib
PHTN
Treatment of MS
diuretics to reduce LAP and volume
Afib treated by rate control using BB, CCB, dig
Require anticoag
Surgery indicated when PHTN develops
Goal with MS
Prevent decreases in CO or produce pulmonary edema
A sudden SVR decrease results in tachycardia, which results in a CO decrease
MS causing CHF
precipitated with excessive fluids
trende
autotransfusion via uterine contractions
Which pressor is preferred in MS?
Vasopressin bc has minimal effects on pulmonary artery pressure
Things to avoid with MS
increasing pulmonary artery pressure by: hypercarbia hypoxemia lung hyperinflation lung water increases
Anesthetic types in MS
Neuraxial if not anticoagulated GA - not ketamine pancuronium bc HR increase, histamine release (atracurium, succ) N2O can increase PVR DES with sudden large changes Lg amts of fluid
Infusion of drugs that maintain bradycardia - fentanyl helpful
Light anesthesia can evokes sympathetic stimulation and SVR/PVR increases
Mitral Valve Regurg
More common than MS
decrease in CO and SV as forward flowing volume flows backwards into the LA.
Volumes of 60% or more are severe MR
Chronic MR results in remodeling of LV in attempt to compensate for loss of CO. the LA remodels to become more compliant for increase filling volume. Acute MR, the presentation is pulmonary edema and/or cardiogenic shock bc these remodeling have taken place
systolic apic murmur that radiates to the axilla
ECHO
Survival with MR
Survival better if surgery when EF is > 60%
Pts with EF <30% do not improve with surgery
Symptomatic pts should have surgery
Repair vs replacing Mitral valve
Repair. Mitral apparatus is part of normal LV chamber and replacement changes this geometry. Repair preserves LV unction
Treatment of MR
Vasodilators to reduce afterload in acute MR but not chronic
Symptomatic pts - ACEI and BB and pacing
Goals of anesthesia in MR
- prevent bradycardia - increases the regurg fraction
- prevent increase in SVR - prevent the LV from increasing forward flow
- minimize cardiac depression
- monitor the regurgitant volume
Volume is extremely important
Fast, full, forward - HR elevated, full volume, maintain forward flow through SVR reduction
Anesthesia meds in MR
Afterload can be reduced with SNP or NTG
Regional provides decrease in SVR
PIA can decrease SVR and increase HR (but do depress contractility and may need to consider narcotic induction with anticholinergics for HR control)
Vent settings in MR
normal rate - too fast will result in poor venous return
MitraClip
percutaneous valve repair
prominent in elderly high risk pts
Mitral valve prolapse
most common valvular disorder in the US
typically benign
dx ECHO with 2 mm or more prolapse
Anesthesia the same as MR
If you detect in preop a pt with systolic click, and pt is asymptomatic, does this warrant a cardiac consult?
Nope
Aortic valve
separates the LV from the aorta, preventing the backflow of blood into the heart during ventricular relaxation
Normal is 2.5-3.5 cm2
Aortic stenosis
Common
Dvlps due to degeneration and calcification of the aortic leaflets which narrows the aortic valve
Risks:
atherosclerosis, htn, DM, smoking, male, bicuspid aortic valve
Pts with BAV and aortic aneurysms
should have repair when the diameter reaches 55 mm of the aneurysm or 50 mm if family hx of rupture
AS symptoms
angina
syncope
DOE
CHF
<5 year life expectancy
Independent risk factor for perioperative risk
Sytolic murmur that radiates into the neck
ECG shows LVH
Pathophys of AS
the need to increase LV pressure to maintain SV
LVT obstruction - causes increase systolic pressure, causing LV failure due to remodeling
angina bc of the increased O2 demand of the enlarged LV
Subendocardial blood flow is depressed from the compression from the increased LVP
Critical AS
AR gradient >50
.8 cm2
ECHO
Surgical AVR - most combined with CABG
AS and BNP
increases from pt baseline can predict worsening of symptoms
After aortic valve replacement - and AS
LV remodeling begins to reverse and the EF increases
Aortic stenosis
high risks for perioperative complications
most pts also have CAD
Want pt in sinus rhythm bc loss of atrial kick and dramatically reduce CO
Hypotension reduces CA flow and potentiates a failing LV
Aggressive treatment of hypotension is warranted
CPR in aortic stenosis pts
ineffective bc cannot generate enough stroke volume across a stenotic valve to perfuse the heart
Anesthesia in AS
no neuraxial bc of sympathetic blockade leading to hypotension and preload reduction
Induction should be with drugs that do not lower SVR - opioids are useful. Benzos and etomidate
Push drugs slowly
Volume
Alpha agonists preferred bc do not cause tachycardia
Ketamine avoided due to HR increases
Avoid NTG bc reduces preload
Avoid PIA bc sino-atrial-depressing
Maintenance should be aimed at maintain SVR and CO
*N2O with opioids
cerebral oximetry due to emboli breaking off
Hypertrophic cardiomyopathy
managed like AS
Repairing the AV
mechanical or bovine/porcine/human
The Ross procedures uses the pat’s pulmonic valve to replace the aortic valve
Aortic Regurg
Failure of the aortic leaflets to couple together
Inflammatory or connective tiussue disease
Acute AR from endocarditis or aortic dissection
diastolic murmur along right sternal border and signs of volume overload
LVH on ECG
Pathophys of AR
CO reductions from regurgitant blood flow during diastole. Produces volume overload. As time increases for backflow, so does the regurg. The pressure gradient also determines the amt of back flow (SVR).
Regurg is decreased by tachycardia and peripheral vasodilation
LV hypertrophies in response to increased filling volumes, consuming more O2 and reducing subendocardial blood flow
Chronic changes are tolerate though remodeling
As the LV fails, pulmonary edema dvlps
Pts with acute AR manifest with ischemia and rapid deterioration into HF
signs of volume overload
widened PP
Decreased DBP
Bounding pulses
Pulmonary congestion
Regurgitant jet volume
Regurgitantvolume=Leftventriclestrokevolume − Rightventriclestrokevolume
Regurgitantvolume=(LVOTarea×LVOTVTI)−(Pulmonaryarteryarea × pulmonaryarteryVTI)
ascending aortic SAX view
Surgery for AR
indicated with EF < 55% and LVESV increases to 55 mL or more (regurgitant volume)
Acute AR is an emergency
Ross procedure
Aortic valve repair
Medical mgmt. for AR
Reduce HTN and improve LV function
Vasodilators and inotropic agents like dobutamine
Nifedipine or hydralazine
Anesthesia for AR
Fast, Full, Forward
HR > 80 to reduce amt of time in diastole
Abrupt SVR increases can cause LV failure - treat with vasodilator and inotrope
GA - induction should not decrease HR or increase SVR to minimize regurg volume
Maintenance with N2- plus PIA and/or opioid
All PIA increase HR and decrease SVR
Fluid status should be normal
Bradycardia and junctional rhythms and AR
Atropine or glycol before ephedrine bc ephedrine will incrase SVR
Tricuspid valve
separates the right atrium from the right ventricle
papillary muscles/chordae tendinae prevent the prolapse of leaflets into the atria
TV regurg
Endocarditis
PHTN
RVH
common - especially in athletes
TV can be removed without much of an effect
Signs are JVP increases, hepatomegaly, ascites, edema
Treatment aimed at the cause of the TR and surgery is rare
TV regurg anesthesia
maintain IV volume in the high-normal range to ensure preload
PPV and vasodilators bad if reduce venous return
Avoid incrase in PVR
Avoid hypoxemia, hypercarbia, N2O
RAP monitoring for CVP trends
TV stenosis
very rare and usually exists with TR and MV/AV disease
RAP is increased and RV effects are usually dependent on concurrent TR for remodeling of the ventricle
eCHO
Pulmonic regurg
PHTN
rarely symptomatic
Pulmonic stenosis
congenital and corrected in childhood
RHD, carcinoid, endocarditis, trauma
Surgical valvotomy is used to relieve symptoms
TAVR
TAVR - severe symptomatic AS pts that inoperable or high risk
higher risk of stroke, complete HB, LBBB, paravalvular regurg
contraindicated in pts with BV
lower 30 day and 1 year mortality, greater improvement in cardiac symptoms, reduced repeat procedures
SAVR
median sternotomy
often with CABG
apply defib pads
TEE
associated with higher bleeding risks and fib
Balloon valvotomy
MS
MR symptomatic pts with LV dysfunction (open heart with bypass)
MV repair
traditional sternotomy with CPB
Partial sternotomy
Right mini-thoracotomy
Endoscopic approach
Robotic procedure - take extra care for padding
*all require GA
Left atrial appendage closure
combat the fact that most afib strokes occur from thrombus formation in the LAA
Watchman LAAC device dvlped as an alternative to oral anticoag for nonvalve afib
GA - takes 1 hr. anticoag needed, fluroscopy, TEE
Must stay anticoagulated for 2 months
