Valvular Heart Disease (2) Flashcards
What are compensatory mechanism for valve disease?
- Increased SNS (anxiety, diaphoresis, resting tachycardia)
- Myocardial hypertrophy
- Current meds (current drug therapy)
What are the New York Heart Association Functional Classifications of patients with heart disease?
Class I: Asymptomatic
Class II: Symptoms with ordinary activity but comfortable at rest
Class III: Symptoms with minimal activity but comfortable at rest
Class IV: Symptoms at rest
What is mitral regurg often associated with?
- IHD
- Endocarditis
- Mitral valve prolapse
- Cardiomyopathy
Mitral regurg pathophysiology:
- Decrease in forward LV SV and Co
- Left atrial volume overload and pulmonary congestion (transforms LV, eccentric hypertrophy, compliance of LA)
- Regurgitant volume (size of the mitral valve orifice, pressure gradient across the mitral valve)
What needs to be evaluated in patients with valvular heart disease?
- Exercise tolerance
- Cardiac reserve
Elective surgery is deferred until _____ can be treated and myocardial contractility optimized
CHF
What causes the sounds with heart murmurs?
Turbulent flow
What are signs of impaired myocardial contractility?
- Dyspnea
- Orthopnea
- Easily fatigability (delay case)
What are signs of heart failure?
- Basilar rales
- JVD
- 3rd heart sound
What causes heart murmurs?
- Turbulent blood flow across abnormal valves
- Increased flow across normal valves
What is the difference in functional/pathologic murmurs?
Functional - murmur that is primarily due to physiologic conditions outside the heart
Pathologic: structural defects in the heart itself
Mitral regurg symptoms:
- History of IHD, endocarditis, papillary muscle dysfunction
- Holosystolic murmur at apex - radiates to axilla
- Cardiomegaly
- Atrial fibrillation
_______ of the murmur in the cardiac cycle is the most important.
Timing
What type of murmur can be a functional murmur?
Midsystolic murmur
Any other murmur is likely pathologic
Which valve disorders have systolic murmur?
- Aortic stenosis
- Mitral regurg
- Tricuspid regurg
- Stenosis of pulmonic valves
What would mitral regurg show on EKG?
- Left atrial and LV hypertrophy
- Atrial fibrillation
Which valve defects have diastolic murmurs?
- Aortic Regurg
*Pulmonic Regurg - Mitral Stenosis
- Tricuspid Stenosis
What would mitral regurg show on chest xray?
- Cardiomegaly
- Left atrial and LV hypertrophy
What is defect suspected by a midsystolic murmur that is heard best at right sternal border and radiates to the carotids?
Severe aortic stenosis
What would mitral regurg show on an echocardiogram?
Left atrial thrombus
Murmur that us heard between S1 and S2 heart sounds in a crescendo/decrescendo pattern:
Midsystolic murmur
When would you want to do surgery for patients with mitral regurg?
Survival rate may be prolonged if surgery is performed before the EF is less than 60% - reducing the risk of HF
When in the cardiac cycle is a holosytolic murmur heard?
Merges with S1 and S2
When in the cardiac cycle is diastolic murmur heard?
Follows S2
Which valve disorder is characterized by holosystolic murmur heard best at the apex?
Mitral Regurg
What are common valve murmur characteristics (refer to chart)
Why would early surgery be warranted for patients with mitral regurg?
To prevent left ventricular dysfunction from becoming severe or irreversible
Where is aortic valve ausculated?
2 ICS right sternal border
Where is pulmonic valve auscultated?
2 ICS left sternal border
What are other treatments for mitral regurg?
- Vasodilators
- Biventricular pacing
- ACE inhibitors
- Beta blockers (carvedilol)
Where is tricuspid valve auscultated?
5 ICS Left sternal border
Where is mitral valve auscultated?
5 ICS mid-clavicular at apex
What diagnostic tool is used to measure:
L atrial enlargement
Axis deviations
Dysrhythmias
Possible ischemia/prior MI?
EKG
In asymptomatic patients with primary MR, surgical intervention is warranted in those with an LV EF of ____ to ____ or an LV end systolic dimension greater than ___ mm
30%, 60%, 40mm
What diagnostic is used to diagnose:
Cardiomegaly
Left mainstem bronchus elevation
Valve calcifications?
CXR
In symptomatic patients with severe primary MR, surgical intervention is undertaken id the LV ejection fraction is greater than ___ and LV end diastolic dimension is less than ___ mm.
30%, 55mm
Cardiomegaly is if heart is >____% of the internal width of thoracic cage
50%
Goal of anesthetic for patients with mitral regurg:
Improve forward LV SV and decrease regurgitant fraction
What causes elevation of the left mainstem bronchus?
Enlargement of the left atrium
Mitral regurg anesthetic considerations:
- Prevention and treatment of decreased CO
- Normal to slightly increased HR
- Avoid increased SVR (don’t use phenylephrine)
- Neuraxial anesthesia - regional anesthesia may be beneficial because of the decreased SVR
- Adjust induction/muscle relaxant to prevent increased SVR or decreased HR
- Volatile anesthetics are okay - cause vasodilation
- Maintain intravascular fluid volume
Which study is better for detecting thrombus? TEE or TTE?
TEE
Which diagnostic test is best to measure coronary blood flow?
Angiography
What diagnostic study is used to resolve discrepancies between clinical and echo findings?
Angiography
When to use echo?
When to use angio?
How does mechanical valve differ from bioprosthetic valve?
Mechanical:
*metal or carbon alloy
* very durable–common for young patients
* require long term AC
* could cause inflammatory process
Bioprosthetic:
* Porcine or bovine
* Shorter lasting
* preferred in elderly patients (less irritating)
* No longer term AC
What is aortic stenosis often associated with?
- Calcific aortic stenosis
- Bicuspid aortic valve (develops earlier in life with BAV than with tricuspid aortic valve)
What percent of the population has a bicuspid aortic valve? (most common congenital valvular abnormality)
1-2%
Can AC for patients with prosthetic heart valves be continued in patients having minor surgeries?
Anticoagulation can be continued in patients with prosthetic heart valves having minor surgeries
Aortic stenosis pathophysiology:
- Obstruction to ejection of blood into the aorta
- Increased LV pressure
- Severe AS valve area < 1cm2
- Always associated with aortic regurg
- Concentric LV hypertrophy
Why are AC for patients with prosthetic heart valves only discontinued for major surgery?
Discontinuation of AC puts patients at risk of arterial or venous thromboembolism (d/t rebound hypercoagulable state)
What is a normal aortic valve area?
2.5 - 3.5 cm2
What type of murmur is heard in aortic stenosis?
Systolic or midsystolic - right upper sternal border
- crescendo-decrescendo pattern
- radiates to neck, mimics carotid bruit
What is common practice if patient is on warfarin needing major surgery?
Unfractionated heparin or LMWH is given after d/c warfarin and continued until day before surgery (bridge to surgery)
What should happen in regards to AC therapy if a female patient with a prosthetic valve on warfarin becomes pregnant?
Warfarin associated with fetal defects
* discontinue warfarin during pregnancy switch to LMWH (can also use low dose ASA with LMWH)
What is a common cause of mitral stenosis?
Rheumatic heart disease–from rheumatic fever as a child (manifests as acute vision changes)
Symptoms of critical aortic stenosis:
- Angina pectoris - 5 years
- Syncope - 3 years
- Dyspnea on exertion - 2 years
How symptoms present with mitral stenosis?
No issues for a long time then present with pulmonary issues (Slow onset)
Is mitral stenosis more common in men or women?
Women–rare in US
In AS, ____ of symptomatic patients die within 3 years without valve replacement
75%
What is normal area of mitral orifice?
4-6 cm^2
What mitral valve diameter do symptoms of mitral stenosis start to appear?
< 2cm^2
What would aortic stenosis show on chest xray?
- Prominent ascending aorta, may have aortic aneurysm
- Aortic valve calcification
What pathologic changes occur in the valve with a stenotic mitral valve?
Diffuse thickening and fibrosis of mitral leaflet cusps, subvalvular apparatus, and commissural fusion
Calcification of the annulus and leaflets
What would aortic stenosis show on EKG?
- LV hypertrophy
- ST depression
- T wave inversion
What would aortic stenosis show on an echo?
- tri-leaflet vs. bi-leaflet valve
- thickened and calcified
- valve area and transvalvular pressure gradients
What changes happen in the heart from mitral stenosis?
- Increase in left atrial volume and pressure
- LV contractility is normal
- SV decreases
Treatment for aortic stenosis:
- Balloon valvotomy for adolescents/young adults
- Transcatheter aortic valve replacement (TAVR)
What are the major symptoms of mitral stenosis?
Pulmonary symptoms:
* Dyspnea on exertion
* Orthopnea
* Paroxysmal nocturnal dyspnea
* Pulmonary edema
* Pulmonary HTN
* Atrial fibrillation
May lead to RIGHT heart failure over time
What diagnostic findings are indicative of left atrial enlargement?
Seen on echo–could indicate mitral stenosis
Anesthetic considerations for aortic stenosis:
- Prevention/avoidance of hypotension and decreased CO
- Maintain NSR
- Optimize intravascular fluid volume (minimize NPO deficits)
- Aggressive treatment of hypotension
- GA > epidural or spinal
- Induction - avoid decreased SVR
- Avoid hypotension with alpha agonists
- Junctional rhythm or brady = ephedrine, atropine or glycopyrrolate
- Tachycardia = beta blockers
**CPR is typically not effective
Common causes of aortic regurgitation:
- Endocarditis
- Rheumatic fever
- Bicuspid valve (BAV)
- Anorexigenic drugs
Acute = endocarditis or aortic dissection
What is seen on CXR that could indicate mitral stenosis Dx?
- Mitral calcification
- Pulmonary edema or vascular congestion
- Elevated left main bronchus (hard to detect unless getting serial CXR)
- Straightening of left heart border
What type of valves issues causes rumbling diastolic murmur at the apex that radiates to the left axilla?
Mitral stenosis
How might mitral stenosis present on EKG?
- Notched P waves
- Afib
What findings on an echo could indicate mitral stenosis?
- Calcification
- Left atrial thrombus
- Left atrial enlargement
What is the treatment for mitral stenosis?
Rate control (BB, CCB, Dig)
Left atrial pressure ↑ (diuretics)
Anticoag (7-15 % risk CVA)
Severe symptoms= surgery
Aortic regurg pathophysiology:
- decreased CO d/t regurgitant SV
- combined LV pressure and volume overload
- Usually slow onset
- SV ejected into the aorta
- Increased LV end-diastolic volume and pressure
- Eccentric hypertrophy an enlarging to accommodate volume overload
- Increased SV and increased systemic blood flow
- EF declines
Magnitude of aortic regurg depends on:
- time available for regurgitant flow (HR)
- pressure gradient across the aortic valve
Mitral stenosis put the patient at high risk for arterial or venous thromboembolism?
Arterial thromboembolism (from stasis of blood in LA)
Surgical treatment options for mitral stenosis:
- Percutaneous valvotomy
- Surgical commissurotomy
- Valve replacement
What is the primary anesthetics goal in patients that have valve disease receiving anesthesia?
Maintain normal HR, normal BP, normal volume
How is SVR/BP maintained in patients with mitral stenosis?
Phenylephrine
Vasopressin
What meds should be avoided in patient with mitral stenosis while in the OR?
Epi, Ephedrine, Glycopyrrolate
What type of murmur is heard with aortic regurg?
Early or mid-diastolic murmur, at the left sternal border
- low-pitched diastolic rumble (austin-flint murmur)
If a patient with mitral stenosis went under GA–what is an important consideration with emergence?
Reverse paralytic with sugammadex→no effect on HR
If a patient with mitral stenosis is having neuraxial anesthesia, what is important to monitor closely and maintain?
Maintain BP, Preload and HR
Epidural anesthesia may allow for better control than spinal
Which inductions meds should be avoided in patients with mitral stenosis?
Ketamine (increases HR)
Pancuronium (histamine release)
Atricurium (histamine release)
What action would you take if patient with mitral stenosis has persistent tachycardia not responding to meds?
Cardioversion
Symptoms of aortic regurg:
- Hyperdynamic circulation (widened pulse pressure, decreased bp, bounding pulses)
- LV failure (dyspnea, orthopnea, fatigue, fatigue and coronary ischemia)
- Acute AR - severe LV volume overload (coronary ischemia, rapid deterioration, LV function, HF)
What would aortic regurg show on EKG and CXR?
- LV enlargement and hypertrophy
What would aortic regurg show on echocardiogram?
- Leaflet prolapse or perforation
- Associated aortic abnormalities
Medical treatment for aortic regurg:
Decrease systolic HTN, LV wall stress, and improve LV function
- Diuretics, ACE inhibitors, CCB
Surgical treatment for aortic regurg:
- AVR
- Aortic root replacement
Anesthetic considerations for aortic regurg:
Goal: maintain forward LV SV
- Avoid bradycardia
- Avoid increased SVR – will worsen lesion
- Minimize myocardial depression
(Vasodilator to reduce afterload, inotrope to increase contractility)
- GA is usual choice
- Induction = inhaled or IV
- Maintain normal levels of intravascular fluid volume to provide adequate preload
