Heart Valves Flashcards
What is the most common form of valvular heart disease in Western countries?
Degenerative valve disease
Which disease accounts for the majority of valvular pathology in developing countries?
Rheumatic heart disease
What are the most commonly encountered valvular lesions in western countries?
Aortic stenosis and Mitral regurgitation
Why are MR and AS the most prevalent in western countries?
AS -> d/t calcific disease
MR -> d/t primary causes like degenerative disease
2ndary cause = ischemic heart disease
How do valvular lesions change the normal physiology of the heart?
Cause pressure and/or volume overload causes concentric and/or eccentric hypertrophy
Stenosis of which valves will be affected during systole?
Aortic and pulmonic
Stenosis of which valves will be affected during diastole?
Mitral and tricuspid
Valvular obstruction can be classified as either fixed or dynamic. Describe the difference between the two.
Fixed: Constant degree of obstruction to blood flow throughout the cardiac cycle (AS)
Dynamic: Variable degree of obstruction dependent on the phase of the cardiac cycle (hypertrophic obstructive cardiomyopathy)
Stenotic lesions cause increased pressure proximal to the affected valve (T/F)
True
Regurgitant lesions cause pressure overload (T/F)
False
Volume overload
Volume overload leads to what type of physiological changes?
Chamber dilation and eccentric hypertrophy
List the 3 ways the LV can respond to changes in pressure/volume
- Activation of the Frank-Starling mechanism
- Use of the adrenergic neurohormonal systems
- Chamber remodeling
As cardiac function declines the Frank-Starling curve is shifted to the _____ & _______
right & flattened
Further increases in left heart filling pressures lead to minimal increases in CO
Explain how activation of neurohormonal system effects CO
Increased fluid retention -> activating the Frank Starling law which increases both sarcomere length and contractility
Explain the pathophysiology of ventricular remodeling
Concentric LV remodeling enables ventricle to beat harder.
Eccentric hypertrophy enables ventricles to hold more volume.
Explain a New York Heart Association (NYHA) score of 1
Asymptomatic
Explain a New York Heart Association (NYHA) score of 2
Symptoms with ordinary activity but comfortable at rest
Explain a New York Heart Association (NYHA) score of 3
Symptoms with minimal activity but comfortable at rest
Explain a New York Heart Association (NYHA) score of 4
Symptoms at rest
List the physical exam findings associated with LHF
Pulmonary edema
Dyspnea
Pink-frothy sputum
List the physical exam findings associated with RHF
Dependent edema
ascites
JVD
hepatomegaly
What are the 4 unstable clinical risk factors that may require delay of sx?
- Unstable angina
- Dysrhythmias
- Severe valvular disease
- Decompensated HF
If patient needs emergency sx, you must delay for a full work up to determine extent of valvular disease (T/F)
False
Emergency sx takes precedence
Explain the steps for systematic evaluation of primary valvular dysfunction
- Category of valvular dysfunction (stenosis/insufficiency/mixed)
- Status of LV loading (filling problem or no?)
- Acute vs. chronic
- Cardiac rhythm & effects on diastolic filling time
- LV function (HFrEF vs. HFpEF)
- Secondary effects on pulmonary vasculature & RV function (Pulm HTN)
- HR
- Perioperative anti coagulation
How does bradycardia with Regurgitant lesions effect the RF and SV
Increase RF and decrease SV
How does tachycardia with stenotic lesions affect SV and myocardial oxygen demand?
Shortens ejection time, decreases SV and increases myocardial oxygen demand
The LV is subject to volume overload as a result of which 2 valvular lesions?
MR & AR
The LV is subject to pressure overload from which valvular lesion?
AS
The LV is subject to volume under load from which valvular lesion?
MS
In chronic valvular dysfunction the heart __________ over time, while acute valvular dysfunction causes severe _____________ ____________
Compensates
Hemodynamic consequences
What is a normal aortic valve area?
2.5 - 3.5 cm2
What is a normal aortic minimal gradient pressure?
2-4mmHg
What is a normal aortic flow rate?
250ml/min
Symptoms at rest occur when the aortic valve is stenosed by how much percentage?
50%
Aortic valve area <1cm2 indicates what level of disease?
Severe aortic stenosis & is associated with increase in peri operative mortality
Aortic valve area <1cm2 produces which triad of symptoms?
- Angina
- Syncope
- CHF
An aortic valve flow velocity of >4m/sec indicates good prognosis (T/F)
False
Indicates poor prognosis
A mean aortic valve gradient pressure >40mmHg indicates poor prognosis (T/F)
True
Describe murmur of AS and where you’ll hear it
Crescendo-decrescendo systolic ejection murmur heard best at RSB 2nd ICS
AS causes what type of hypertrophy?
Concentric
Increased pressure is needed to overcome impedance
The consequence of LVH in AS is a:
- __________ in ventricular compliance
- ___________ remodeling
- ___________ in intrinsic contractility of the myocardium
Decrease
Hypertrophic
Decrease
True or false
Reduction in ventricular compliance from AS leads to higher filling pressures required to produce the same amount of ventricular work
True
The cardiac rhythm does not matter to achieve adequate LV filling
True or false
False
NSR is required to ensure adequate LVEDV from the atrial kick
Concentric ventricular hypertrophy _________ myocardial O2 demand
INCREASES
Why does concentric ventricular hypertrophy increase myocardial O2 demand?
- Myocardial Mass increased
- Isovolumetric contraction uses more energy than ventricular ejection (high intracavitary pressure must be generated to Maintain CO
- EF phase prolonged (diastole shortened)
Why does concentric ventricular hypertrophy decrease O2 supply?
- CPP is decreased d/t increased LVEDP
- Systolic coronary flow is absent
- Prolonged systolic ejection reduces the coronary perfusion interval
- Subendocardial capillaries are compressed d/t myocardial hypertrophy
What changes to the pressure volume loop would you expect in AS?
Shifted up
What ECG changes would you expect from AS?
Lateral leads show increased voltage, T wave inversion
Based on the Aortic stenosis classification system, stage 0 would show what manifestations?
No cardiac damage, no echo changes
Based on the Aortic stenosis classification system, Stage 1 would show what manifestations?
LV damage
Increased LV mass index
LVEF <50%
Based on the Aortic stenosis classification system, stage 2 would show what manifestations?
LA or Mitral damage
Moderate-severe mitral regurgitation on echo
AF
Based on the Aortic stenosis classification system, stage 3 would show what manifestations?
Pulmonary vasculature or tricuspid damage
Systolic pulm HTN on echo >60mmHg
Moderate-severe tricuspid regurgitation
Based on the Aortic stenosis classification system, stage 4 would show what manifestations?
RV damage
Moderate-severe RV dysfunction
Anesthetic considerations for AS?
MAINTAIN
*NSR
*HR 70-80
*Maintain preload (LVEDV) to maintain CO
*Adequate CPP (maintain DBP)
*Avoid myocardial depression
*Maintain or increase afterload
*GA preferred
Use neuraxial with extreme caution
Define Aortic insufficiency (aortic regurgitation)
Incomplete coaptation of the aortic valve leaflets in diastole and may be caused by disease processes that affect the aortic valve leaflets, aortic root, or both.
Causes portion of blood ejected from LV into the aorta regurgitated back into ventricle because of incomplete closure of aortic valve
What type of murmur will be auscultated with AI? And where will you hear it?
Diastolic murmur, blowing or swishing best heard over the LV
Does the intensity of the AR murmur correlate with the severity of the murmur
No
List the cause of Primary acute AI
Infective endocarditis - resulting in direct damage to aortic valve cusps
List the cause of primary chronic AI?
Rheumatic valvular disease (almost always involves mitral valve)
List the cause of secondary acute AI?
Aortic root dissection caused by trauma or aneurysm
Chronic overload of LV leads to _________ ventricular hypertrophy and chamber dilation
Eccentric
Dilation
The degree of aortic regurgitation depends on
1. _________ time available for regurgitation to occur
2. Diastolic __________ _________ between aorta and LV
3. Degree of ________ of aortic valve
Diastolic
Pressure gradient
Incompetence
AS murmur is a _______ pitched, ________ decrescendo murmur, loudest along the left sternal border
High
Blowing
Left sternal border
End stage AR is characterized by (4)
Myocardial Failure
Decreased CO
Elevation of LVEDV
Evidence of pulmonary Congestion
Causes of leaflet abnormalities that cause AR (5)
- Congenital abnormalities of aortic valve
- Rheumatic disease
- Infective endocarditis
- Calcific degeneration
- Myxomatosis degeneration
Etiologies of aortic root abnormalities (AR)
Idiopathic aortic root dilation
HTN induced annuloaortic ectasia
Aortic dissection
Marfan syndrome
Ehler-danlos syndrome
Aortic is (syphilitic)
Rheumatoid arthritis
Ankylosis spondylitis
Mortality rate for patients is asymptomatic AI is ______% per year
Mortality rate for patients who are symptomatic _____% per year
0.2
10
At what point is Aortic valve replacement recommended in AR?
When evidence suggests that increase in LV volume result in left ventricular dysfunction
In AR, _______ may occur in absence of CAD, often at night, d/t bradycardia with subsequent fall in diastolic pressure and _______ Regurgitant volume.
Angina
Increase
Anesthesia and sx is an added stress to body & can push asymptomatic pt’s to point of decompensation due to anesthesia-induced ____________ _____________
myocardial depression
What are hemodynamic goals during anesthesia for pt’s with AI?
FAST, FWD, FULL
HR maintained between 80-100 (FAST)
afterload decreased (FWD)
Preload increased or maintained (FULL)
myocardial depression avoided
NSR
Normal Mitral valve area
4-6cm2
At what size area does MS generally develop?
<2cm2
Mitral stenosis (MS) occurs after _________ _____ _______ & results from profressive fusion & calcification of valve leaflets
rheumatic heart disease
Which valvular lesions are more common in developing countries
MS and AR
MS less common in western countries d/t early _________ and treatment of _____________ ___________.
detection
streptococcus pharyngitis
Symptoms of MS usually occur ______ to ______ years after RHD
20 - 30
______% of patients with RHD will have some form of mitral valve involvement
90
List the etiologies of MS
rheumatic heart disease
severe mitral annular calcification
radiation associated valve disease
carcinoid syndrome
LA myxoma
rheumatoid arthritis
SLE
iatrogenic MS after MV repair sx
Changes to MV with MS include fusion, thickening, calcification, of the ____________ & ____________ ____________
Leaflets & chordae tendinae
In MS, chronic stress of the turbulent flow through the deformed valve leads to a _________ at the apex of a narrow-shaped, fish-mouth valve
narrowing
Hemodynamic consequences of MS include
__________ LA volume & pressure is dependent of the ________ of MS, CO, & HR
Increased, severity
In mild-mod MS - LA pressure only minimally elevated @ rest but _______ w/exercise, conditions that increase HR, like ________.
increases, AFIB
In severe MS - LA pressure significantly elevated at rest leading to _____________ _________, RHF, & symptoms at rest
pulmonary HTN
In MS, LV function is ________ ________
generally preserved
Clinical presentation of MS
RHF
SVT/AFIB
dypnea on exertion
pulm HTN
hemoptysis
CP
ascites
BLE Edema
Ortner syndrome
What is Ortner’s syndrome?
Horseness d/t LA compressing the RLN
MS murmur is characterized by an opening snap early in ________, best heard during expiration, followed by a ______-pitched rumbling diastolic murmur. Best heart at apex w/pt in Left lateral decubitus position
diastole
high-pitched
apex
What type of ECG abnormality might you find in lead II in a patient with MS
P-mitrale
(M shaped P wave)
Anesthesia consideration for pt’s with MS
Neuraxial anesthesia - epidural > spinal
Focus on preventing & treating events that decrease CO or produce pulm edema
Treat dysrhythmias promptly
Avoid Ketamine & N2O
Avoid hypoxia & hypercarbia
HR 60-80
Maintain preload
Limit Trendelenburg (prevent dependent edema)
What is MR
backward flow of blood into LA during systole with compensation via LV dilation & increasing EDV
Acute Etiology of MR:
Papillary muscle dysfunction or rupture of chordae tendinae from MI & ischemia
Acute rheumatic fever
Endocarditis
Balloon Valvuloplasty
Penetrating chest wound
Chronic etiology of MR:
Primary abnormality of one or more components of the ___________ _________, or 2ndary to another ________ disease
valvular apparatus
cardiac
Degree of MV regurgitation (regurgitant fraction) is related to (4):
- size of the regurgitant valve _________
- _________-_________ between LA & LV
- Time available for _______
- Aortic ________ _______ (SVR)
- orifice
- pressure-gradient
- regurgitation (systole)
- outflow impedance
In MR, increase LA volume = high risk for development of _______ & __________ ________
AFIB
thrombus formation
Clinical presentation of pt’s with MR
asymptomatic until LA enlargement causes:
Pulm HTN or AFIB
Severe acute/chronic MR: symptomatic HF with pulm edema
List symptoms of MR
exertional dyspnea
fatigue
palpitations
Pulm HTN
Afib
Hoarseness - Ortner’s syndrome
Anesthetic considerations for patient’s with MR
FAST, FWD, not FULL
Avoid bradycardia
Avoid increases in systematic vascular resistance
Minimus myocardial depression
Maintain fwd SV and CO
What is Mitral valve prolapse
bulging of one or moth mitral valve flaps into LA during contraction of the heart. May progress to MR or cause emoli or infective endocarditis
MVP woman are _____ times more likely than men to develop
3
Primary MVP is characterized by
*thickening, and fibrosis of the ________
*Thinning/lengthening of the ______ ____________
*frequently associated with __________ ________
Leaflets
chordae tendineae
marfan’s syndrome
2ndary MVP is characterized by:
____________ damage to papillary muscles attached to chordae tendineae
Damage to________ themselves during MI, RHD, hypertrophic cardiomyopathy
Ischemic
valves
MVP pathophysiological changes primariy effect the _____ & _______ _______
cusps & chordae tendineae
CLinical presentation of pt’s with MVP
Undiagnosed in majoity of pt’s
PVCs
Prolonged V-tach
Symptoms of MVP
weakness
dizziness
syncope
atypical CP
Palpitations
Anesthetic considerations for MVP
Full
FWD
Decrease contractility
Low HOB
Normal Tricuspid valve area
7-9cm2
What is Tricuspid stenosis?
Persistent diastolic pressure gradient between RA & RV. Typically leaflets thickened with limited mobility, reduced separation of leaflet tips & diastolic doming of the valve
Etiology of TS
RHD
Carcinoid syndrome
Infection endocarditis
Hypereosinophillic syndromes
RA tumors causing functional stenosis
Congenital causes
Symptoms of TS
Systemic venous congestion
JVD
Ascites
Peripheral edema
Hepatomegaly
Hepatic pulsations
Anasarca
What area indicates severe TS?
<1cm2
What ECG abnormalities would you anticipate with TS?
Tall peaked p-waves in leads II, III, aVF (RA enlargement)
TS murmur is a soft ________ heard loudest of the 3rd & 4th ICS near the _______
Mid-diastolic
LSB
Tricuspid regurgitation is more commonly a 2ndary lesion with or without ________ tethering
Leaflet
TR etiology
RV ischemia
Severe pulmonary HTN
Dilated cardiomyopathy (leads to RV pressure & volume overload)
Infective endocarditis
Carcinoid syndrome
RDH
Tricuspid valve prolapse
Epstein anomaly
Implantable devices leads that cross the RV
TR symptoms
Usually not present until advanced stages
RHF - fatigue, edema, ascites, painful hepatosplenomegaly
May have sensations of pulsations in the neck w/severe disease
TR murmur is a ________ murmur along the LSB that _______ with inspiration
Holosystolic
Intensifies
Diagnostic findings with TR
ECG - R axis deviation
CXR - enlarged R heart border & obliteration of the retrosternal window
Echo - diagnostic of choice for evaluation of TR
Evaluation of the severity, valve morphology, R chamber size, RV function
Pulm pressures can be est.
Anesthetic mgmt of TR
Maintain Intravascular fluid volume
CPS in high-normal range to facilitate adequate RV preload & ventricular filling
HR normal - high
Inotropic support
Avoid: hypeercarbia, hypoxia, hypotension, myocardial depression, N2O (increased PVR)
Techniques to blunt sympathetic response to laryngoscope
Consider peripheral nerve blocks
