Valvular Heart Disease (Exam II) Flashcards
What is the incidence of valvular disease in the US population?
2.5%
Most frequently encountered cardiac valve lesions
- Produce pressure overload i.e. mitral or aortic stenosis
or - Produce volume overload i.e. mitral or aortic regurgitation
- Valvular heart disease and ischemic heart disease frequently co-exist
- Mitral regurg d/t ischemic heart disease increases mortality
Pre-op Evaluation
- Assess: Severity of cardiac disease, degree of contractility, and presence of major organ system disease
- Compensatory mechanisms: increased SNS, hypertrophy and what current therapy they are on [SHYT]
What is the NYHA Functional Classification of Patients with Heart Disease?
I - Asymptomatic.
II - s/s with activity but relieved by rest.
III - s/s w/ minimal activity, relieved by rest.
IV - s/s at rest
What causes a murmur?
Turbulent flow across a heart valve
or increased flow across a normal valve
Systolic murmurs are caused by what valve pathologies?
- Aortic/Pulmonic Stenosis
- Mitral/Tricuspic Regurgitation
Diastolic murmurs are caused by what pathologies?
- Aortic/Pulmonic Regurgitation
- Mitral/Tricuspid Stenosis
_____ murmurs follow S2.
Diastolic
Midsystolic murmurs occur when?
Between S1 and S2 sounds
Best heard at Right upper sternal border, radiates to carotids (suggests aortic stenosis, a functional murmur, or hypertrophic cardiomyopathy)
Holosystolic murmur is heard when and where?
Merges with S1 and S2
heard best at the apex and radiates to the axilla (suggests mitral regurg)
Which murmur type exhibits a crescendo-decrescendo pattern?
Mid-systolic Murmurs
Aortic stenosis Maneuver to change the sound
-At the 2ⁿᵈ ICS, right sternal border
-Increases with squatting
-Decreases with Valsalva and standing (Midsystolic crescendo-decrescendo)
Maneuver to increase aortic Regurg sound
At the 2ⁿᵈ ICS, left sternal border, increases with hand grip or BP cuff inflation (Early diastolic murmur)
Maneuver to increase mitral stenosis sound
At the apex, increases with tachycardia (Mid-Diastolic)
Maneuver to increase mitral regurg sound
At the apex, the sound increases with handgrip or BP cuff inflation (holosystolic)
What maneuver would increase the Tricuspid regurg sound?
At the lower left sternal border, sound increases with inspiration (holosystolic)
Mitral valve prolapse maneuver to increase the sound
At the apex, this sound increases with Valsalva or standing (Late systolic murmur)
Hypertrophic cardiomyopathy maneuver to increase the sound
At the lower left sternal border, the sound increases with Valsalva or standing (Midsystolic murmur)
Functional maneuver to increase the sound
At the Left sternal border, this sound may increase with exercise (midsystolic crescendo-decrescendo)
What factors seen on a chest x-ray would indicate valvular disease?
- Cardiomegaly
- Left Bronchus Elevation
- Valvular Calcifications
What signs seen on an EKG could indicate valvular disease?
- LA enlargement (broad, notched p-wave)
- Axis deviations
- Dysrhythmias
- Possible ischemia or previous MI
What to evaluate on an Echo
-Cardiac anatomy and function
-Presence of hypertrophy
-Cavity dimensions
-Valve area
-Transvalvular pressure gradients
-Magnitude of valvular regurgitation
-Significance of murmurs
-Ventricular EF
-Evaluate prosthetic valve function
What to evaluate with Angiography
-Presence and severity of valvular stenosis and/or regurgitation
-Coronary artery disease
-Intracardiac shunting
-Transvalvular pressure gradients
-Clinical vs echocardiographic findings
What type of valve replacement is thrombogenic?
Mechanical (preferred in young patient, have a life expectancy more than 10-15 years or already require long-term anticoagulation therapy for another reason like a-fib)
What are bioprosthetic valves made from?
Porcine or bovine (preferred in elderly patients and in those who cannot tolerate anticoagulation)
Which type of prosthetic valve is longer lasting?
Mechanical
Anesthesia with anticoagulation therapy
- Temporary discontinuation of Warfarin puts pts with mechanical heart valves or a-fib at risk of thromboembolism due to rebound hypercoagulable state
- Anticoagulation may be continued in patients with prosthetic heart valves going to minor surgery (blood loss will be minimal)
- When major surgery is planned, D/C warfarin 3-5 days preop
Who is most commonly affected by mitral stenosis?
- Women
- Rheumatic patients
(this diagnosis is rare in the US)
What is the normal mitral valve orifice surface area?
4 - 6 cm²
At what surface area do symptoms for mitral valve stenosis start to develop?
< 2 cm²
What are the s/s of mitral stenosis?
- Exertional dyspnea
- Orthopnea
- Paroxysmal nocturnal dyspnea
- Pulmonary edema
- Pulmonary HTN
- A-Fib
How is mitral stenosis treated?
- Rate control (80bpm goal)
- ↓LAP (diuretics)
- Anticoagulation
- Surgical correction
What EKG abnormalities are common with mitral stenosis?
- Notched P waves
- A-Fib
What are the anesthetics goals for a patient with mitral stenosis?
Maintain normal parameters for HR, volume status, and afterload.
- Avoid ketamine because it increases HR
- Avoid histamine releasing NMBs (pancuronium and atracurium)
What is more common, mitral stenosis or regurgitation?
Regurgitation (2% of US population)
What type of murmur would be auscultated with mitral regurgitation? What other s/s are associated?
Holosystolic murmur at the cardiac apex
- Cardiomegaly
- AFib
- Hx of: IHD, endocarditis, papillary muscle dysfunction
What less invasive cath lab procedure is used to treat mitral regurgitation?
Mitra-clip
What β-blocker is preferred for mitral regurgitation?
Carvedilol
What are the anesthetic goals for mitral regurgitation patients?
***avoid bradycardia!! Slightly increased HR
- Improve LV stroke volume & decrease Regurg
- Prevention and treatment of decreased CO
- Use Nitroprusside (vasodilators)—>Avoid increased SVR
Neuraxial anesthesia may be beneficial in some patients because of the decrease in SVR
What heart rate would you want to maintain with mitral regurgitation?
Normal to slightly increase HR
Bradycardia will increase LV volume overload.
What type of pathology would cause early-life development of aortic stenosis?
Bicuspid Aortic Valve
What is the normal surface area of the aortic valve?
2.5 - 3.5 cm²
What is the surface area of a severely stenotic aortic valve?
< 1 cm²
What pathology would be expected for a systolic or mid-systolic murmur hear in the right upper sternal border?
Aortic Stenosis
What symptoms are seen with aortic stenosis becomes critical?
- Angina
- Syncope
- Dyspnea on exertion
____% of aortic stenosis patients will die within three years without a valve replacement
75%
What EKG characteristics would be seen for a patient with aortic stenosis?
- ST depression
- T-wave inversion
- LV hypertrophy
What non-surgical treatments are available for aortic stenosis?
- Balloon valvotomy for younger patients
- TAVR
What type of anesthetic technique is generally better for patients with aortic stenosis?
General Anesthesia
-avoid SVR decrease
-preload dependent
-avoid ketamine
- Prevention/avoidance of hypotension and decreased CO
- Maintain NSR
- Avoid bradycardia or tachycardia
- Optimize intravascular fluid volume
- Aggressive treatment of hypotension
**CPR is typically not effective
What are common causes of chronic aortic regurgitation?
- Endocarditis/rheumatic fever
- Bicuspid AV
- Anorexigenic drugs
What are the two common causes of acute aortic regurgitation?
- Endocarditis
- Aortic dissection
What two factors determine the degree of regurgitant blood flow from a dysfunctional aortic valve?
- Time available for flow (HR)
- Pressure gradient (SVR)
What type of murmur would be heard with aortic regurgitation?
Early to mid-diastolic murmur at left sternal border
What blood pressure abnormalities are often seen with aortic regurgitation?
- Widened pulse pressure
- decreased dBP
- Bounding pulses
Treatment for aortic regurgitation
- Medical
-Decrease systolic HTN, LV wall stress, and improve LV function
-Diuretics, ACE-I, CCB
-Surgical
-AVR
-Aortic root replacement
Aortic Regurg Anesthetic considerations
- Goal: maintain forward LV SV
- Avoid bradycardia - increasing diastole will increase the time for AR and with increase LV overload
-HR: > 80 bpm - Avoid increased SVR
- Minimize myocardial depression
-Vasodilator to reduce afterload
-Inotrope to increase contractility
*GA is usual choice
Induction: Inhaled anesthetic or IV drugs - NMBDs w/ minimal or no effect on BP
- Intravascular fluid volume - normal levels to provide adequate preload
