1. Aortic Insufficiency

2. Outline Epidemiology Etiology Pathophysiology
Clinical Presentation / Symptoms
Natural History
Diagnosis
Physical Exam
Echocardiography
Treatment
Medical
Surgical
What’s new?

3. Epidemiology Prevalence Framingham Offspring Study
13% in men; 8.5% in women
Advanced age and male gender associated with AR
Singh,et al. American Journal of Cardiology.1999:83:
Strong Heart Study (Native American Population)
10% prevalence
Advanced age and aortic root diameter associated with AR
Lebowitz, et al. JACC. 2000;36:461-7.
In both studies the majority of cases were mild

4. Etiology Valvular vs. Aortic Root Valvular Calcific AS in the elderly
Infective endocarditis
Congenital bicuspid
More commonly stenosis
Incomplete closure/prolapse can lead to isolated regurgitation
Rheumatic fever
Cusps become infiltrated with fibrous tissue and retract preventing cusp apposition during diastole
Less Common
Congenital: quadricuspid
Inflammatory conditions: SLE, RA, AS, Whipple’s Disease, Takayasu
Anorectic drugs

5. Etiology Aortic Root Disease
Age related (degenerative) aortic dilation
HTN longstanding
HLD
Cystic medial necrosis (+/- Marfans)
Aortic dilation related to bicuspid valve
Osteogenesis imperfecta
Syphilitic aortitis
AS, Bechets, Psoriatic arthritis, GCA

6. Pathophysiology Regurgitant flow produces increase in LVEDV
Thereby raising wall tension (via Lapace’s law)
Wall stress proportional to (Intraventricular pressure x radius)/wall thickness
LV responds by compensatory eccentric hypertrophy of myocytes
Replication in series and elongation of myocytes and myocardial fibers (Different from AS)  Dilation
Chronic compensated AR: sufficient wall thickening occurs so that ratio of wall thickness to cavity radius remains normal.
Maintains End diastolic wall stress normal
LV responds to volume load with increase EDV, chamber compliance accommodating increased volume without increased pressure

7. Pathophysiology (con’t)
During chronic compensated AR LV is able to adapt to increase in diastolic volume without increasing LV EDP.
LV produces a larger total SV to compensate for regurgitant flow
Over time progressive interstitial fibrosis reduces LV compliance leading to chronic decompensated phase.
Chronic volume overload results in impaired LV emptying, increasing LVEDP and LVEDV causing further dilation and decreasing EF

8. Pathophysiology
Patients with severe chronic AR have the largest LVEDV of those with any form of heart disease (cor bovinum)
In contrast to AR, AS has pressure overload induced hypertrophy (concentric) with replication in parallel
This leads to increased ratio of wall thickness to radius

9. Symptoms Exertional dyspnea Orthopnea Parosxysmal nocturnal dyspnea
Angina pectoris
Late in clinical course
Uncomfortable awareness of heartbeat
Laying down
Thoracic pain
PVCs great heave of volume loaded LV during post extrasystolic beat cause distress
Complaints may be present for many years before symptoms of overt LV dysfunction manifest

10. Natural History of Chronic AR
Asymptomatic patients with normal EF
No large scale studies evaluating this population
Current ACC recs derived from 9 published series involving 593 patients with mean F/U 6.6 years
Progression to symptoms and/or LV dysfunction: <6%/yr
Progression to asymptomatic dysfunction: <3.5%/yr
Sudden Death: <0.2%/yr
Two multivariate analysis identified two independent predictors of outcome (symptoms, death of LV dysfunction.)
Age
LVEDV
EDV > 50 mm 19% annual
EDV mm 6%/yr
EDV < 40 mm <1%/yr

11. Natural History of Chronic AR
Patients with asymptomatic LV Dysfunction
Most develop symptoms requiring AVR in 2-3 years
Symptom onset 25% annually
Patients with symptomatic AR
No long term studies on this population as most proceed to AVR
Mortality rate of 10% annually if pt has angina
Mortality rate of 20% annually if pt has heart failure
Bonow, Circulation 1991, 84:

12. Physical Exam Palpation Auscultation
Apical impulse enlarged, displaced lateral to midclavicular line in 5th intercostal space
Diastolic thrill and systolic thrill in second intercostal space (increased aortic flow)
Auscultation
Diminished S1 (prolonged PR, LV dysfunction, preclosure of MV)
S2 soft, maybe paradoxically split
S3 may be heard with LV dysfunction (indicating increased LV EDP)
S4 often present (LA contraction into poorly compliant LV)
Blowing diastolic decrescendo murmur starting immediately after A2.
LUSB, diaphragm of stethoscope
Sitting up and leaning forward
Full expiration
Severity correlates with length/duration not intensity of murmur
May hear second diastolic murmur at apex in severe AR
Austin Flint: middle to late diastolic rumble
May hear short midsystolic ejection murmur at base radiating to neck reflecting increased ejection rate (don’t confuse with AS)
Maneuvers
Increase: isometric exercise, squatting, inotrope infusion
Decrease: standing from squatting, valslava, inhalation of amyl nitrite
LV enlargement: apical impulse
Austin Flint: vibration of anterior mitral leaflet as it is struck by regurgitant jet, or by rapid antegrade flow across a mitral orifice that is narrowed by rapidly rising LVEDP
AR murmur distinguished from PR murmur by its earlier onset (after A2 rather than P2)
AR murmur due to valve dx heard best 3 or 4 LSB, ascending aorta AR heard better over RSB

13. Physical Exam: Peripheral Pulses
Rapid upstroke followed by quick collapse
Water-hammer/Corrigan’s pulse
Head bob with each heartbeat
De Musset’s sign
Pistol shot sounds heard over femoral arteries in systole and diastole
Traube’s sign
Systolic pulsation of the uvula
Muller’s sign
Capillary pulsation visible in nailbed
Quincke’s sign
Popliteal cuff systolic pressure exceeding brachial cuff systolic pressure by > 60 mm hg
Hill’s Sign
Arterial pulsations visible in retinal arteries and pupils
Becker’s sign

14. Laboratory Evaluation
EKG and CXR
Echocardiogram gold standard
Two dimensional: cause of AR
Rheumatic: thickening and retraction of leaflet tips failure of cusp apposition
Endocarditis: leaflet fibrosis and retraction, leaflet perforation or flail of the valve cusp
Aortic root seen on parasternal long axis
Symmetric dilatation causes central jet
Focal dilatation results in eccentric jet
EKG: LVH, LAD, LAA, conduction abnormalities unusual (PACs and PVCs occur)
CXR: marked cardiomegaly with heart displaced inferiorly and leftward

15. Echocardiogram M- Mode
May reveal premature closure of the mitral valve (Fluttering in diastole)
Diastolic opening of aortic valve (severe, acute)
M-Mode’s rapid sampling best for picking up fluttering, early closure due to rapidly increasing LV diastolic pressure
RV, IVS, LV (black space), Fluttering of mitral valve) the Posterior wall

16. Echocardiogram Color Flow
Assessment of jet origin, size and direction
Parasternal long axis and short axis (TTE)
LVOT view (135 degree transducer position of TEE)
Sensitivity 95%, specificity near 100% (Feigenbaum)
FN rare: can occur in setting of increased HR (short diastole), should use CW for detection
Max length of jet poorly correlated with angiographic severity of AR
Short axis regurgitant jet area relative to short axis area of LVOT at aortic annulus correlates best with angiographic severity of AR

17. Echocardiography Continuous wave allows for measurement of:
Density of jet (qualitative indication of the volume of regurgitation)
Velocity
Rate of deceleration
Because AR jet invariably high velocity, continuous wave necessary for contour of envelope
CW does well to differentiate between MS and AR

18. Echocardiogram
Pulse wave Doppler relies on demonstration of turbulent flow during diastole in LVOT
Highly sensitive but requires methodical and careful search for jet using multiple views and windows
False positive: mitral stenosis or prosthetic mitral valve where turbulent diastolic flow can be mistaken for AR

19. ACC Guidelines on Echocardiogram
Class I indications (LOA)
Confirm presence and severity of acute or chronic AR (B)
Diagnosis and assessment of cause of chronic AR and assessment of LV hypertrophy, EDV, and EF (B)
Patient with enlarged aortic root to assess for regurgitation (B)
Radionuclide angiography or MRI indicated for initial and serial assessments of LV volume and function at rest in pts with suboptimal TTE (B)
Re-evaluate mild, moderate or severe AR in patient with new or changing symptoms (B)

20. Evaluating Severity of AR on ECHO
Multiple methods for measuring AR, each with its own limitations
Important to obtain multiple measurements in multiple views
Size and extent of jet within LV
Jet Width/LVOT diameter
Jet area/LVOT diameter
Pressure Half Time
Quantify regurgitant volume and regurgitant fraction
PISA
Diastolic Flow Reversal

21. Severity: Color Flow
Most common is to examine size of regurgitant jet and regurgitant volume
Length of jet conveys unreliable information about overall severity.
Important to examine at its origin (immediately downstream of AoV)
Parasternal long axis
Height (width) of jet just below valve measured
Can also be expressed as percentage of LVOT dimension
Limitations
Eccentric jets
Changes in gain, color scale, transducer frequent, wall filters
Changes in View (apical vs. parasternal)
Eccentric jets: become entrained along wall of LB altering their appearance and perception of severity
Instrument dependant factors
Views: apical views make width of jet appear larger

22. Severity Color Flow

23. Severity: Continuous Wave
Compares density of envelope of the antegrade aortic flow and regurgitant jet
Larger the volume the darker the jet
Mild AR
Compliant LV allows slow and modest increase in LVP and aortic diastolic pressure is maintained throughout
Regurgitant velocity remains high = flat envelope (Long Pressure half time)
Severe AR
Increase LVP and rapid decrease in aortic pressure leads to rapid deceleration of regurgitant jet velocity
Steep slope of Doppler wave (Pressure Half Time)

24. Severity: Continuous Wave

25. Severity Pulse Wave
Pulse wave can be used to assess diastolic flow reversal in descending aorta
Dependent of vessel compliance and stroke volume
Holosystolic flow reversal in proximal descending aorta is diagnostic of severe AR

26. Severity: Other Can use PISA to calculate ERO
Technical challenges of visualizing isovelocity shells
Quantifying regurgitant volumes
All four valves in series, SV across each is equal
Total SV across AoV = Regurg Vol .+ Forward Vol.
SV = CSA x TVI
CSA = (pi)r2 = x diameter2
Regurg Volume = SV AV – SV MR
CSA: Cross sectional area
TVI: Time velocity integral

27. Classification of Severity

28. Cardiac Catherization
For patients with poor echo images aortography provides semi quantitative assessment of AR severity
1+ - mild – contrast incompletely opacifies LV but clears with each beat
2+ - moderate – faint complete opacification of LV, rapidly clears
3+ - mod-severe – opacification of LV matching aorta
4+ - severe – opacification of entire LV on first beat, more intense than aorta, slow clearing
Coronary angiography indicated prior to surgery in patient’s > 50 years old

29. ACC Guidelines on Catherization in AR
Class I
Assessment of severity of AR, EF, or aortic root size when noninvasive tests are inconclusive or discordant with clinical findings in patients with AR (B)
Coronary angiography indicated before AR in patients at risk for CAD (C)
Class III
Not indicated for assessment of EF, aortic root size, or severity of AR before AVR when non-invasive tests are adequate and concordant (C)
Not indicated for assessment of LV function and severity of AR in asymptomatic patients (C)

30. Medical Therapy Surgical Indications Serial Follow Up
Management
Medical Therapy
Surgical Indications
Serial Follow Up

31. Medical Therapy
Vasodilating agent therapy designed to improved forward SV and reduce regurgitant volume
Decrease LV EDV
Decrease wall stress
Decrease afterload
Hydralazine, nitroprusside produce acute hemodynamic changes
Decrease EDV
Increase EF
Nifedipine or felodipine
Inconsistent results

32. Randomly assigned 95 patients with asymptomatic severe AR and normal LV EF to open label nifedipine, open label enalapril or placebo
Mean 7 year follow up
Primary end points: LV dimension on TTE, symptoms, need for surgery

33. Vasodilators?
Exclusion: EF< 50%, other valvular disease, DBP > 90, Afib, Hx CAD
Defined severe AR as:
Regurg fraction > 60% or
Jet width > 10 mm AND jet area > 7 cm2
No reduction in development of symptoms or LV dysfunction warranting surgery
No difference in LV dimension, EF, or mass

34. Medical Therapy ACC Guidelines
Class I
Vasodilator therapy indicated for chronic therapy in severe AR with symptoms or LV dysfunction when surgery not recommended
Class IIa
Vasodilator therapy is reasonable for short term therapy to improve hemodynamic profile prior to surgery
Class IIb
Vasodilator therapy considered for long term therapy in asymptomatic patients with severe AR, LV dilatation and normal systolic function

35. Medical Therapy: ACC Guidelines
Class III
Vasodilator therapy not indicated in asymptomatic patients with mild to moderate AR and normal EF
Not indicated in asymptomatic patients with LF systolic dysfunction who can undergo surgery
Not indicated in patients with normal EF or mild to moderate LV systolic dysfunction who are candidates for AVR

36. Indications for Surgery
Indications for repair and replacement are the same
Symptomatic Patients with normal EF (>50%)
AVR for NYHA Class III or IV
AVR indicated for Canadian Class angina II – IV
Symptomatic Patients with LV dysfunction
AVR indicated for NYHA class II-IV and EF 25-50%
Class IV have worse post op survival
NYHA IV and EF < 25% difficult management scenario
Some get meaningful LV recovery post op
Many have developed irreversible damage

37. Indications for Surgery
Asymptomatic patients
Controversial topic
Generally agreed
Indicated in patients with LV dysfunction on 2 consecutive measurements
1 month apart or
Two modalities
Indicated for severe LV dilatation
EDD > 75 mm or ESD > 55 mm
Aortic Root
Root > 5 cm in diameter and ANY degree of AR

38. Serial Follow Up
Goal is to detect changes in hemodynamic parameters prior to symptoms
Asymptomatic patients with mild AR, little or no LV dilatation, normal EF
Q1 year exams
No need for annual TTE
Asymptomatic patients with normal EF but severe AR and LV dilation ( > 60 mm)
Q 6 month exam and echo
Immediate TTE in any patient with onset of symptoms
Serial exercise testing, radionuclelide v-grams or MIR not indicated

39. What’s New in AI

40. Average age 35 (+/- 16 years) Main Outcomes:
642 consecutive bicuspid AoV patient presenting to Canadian Congenital Heart Clinic
Followed for 9 years
Average age 35 (+/- 16 years)
Main Outcomes:
All cause mortality
Cardiac death
Intervention on aortic valve or ascending aorta
CHF requiring hospitalization
JAMA 9/17/ (11):

41. Results 161 had primary cardiac events (1 or more)
17 deaths
142 interventions on aorta or AoV
11 Aortic dissections or aneurysms
16 CHF exacerbations requiring hospitalization
Independent predictors of primary cardiac events
Age > 30 (Hazard ratio with CI: 3.01, )
Moderate to severe AS (5.67, )
Moderate to severe AR (2.68, )
10 year survival not significantly different from population estimates

42. References
2008 Focus Update Incorporated into 2006 ACC/AHA guidelines for Management of Patients with Valvular disease. JACC. 2008:52 e1-e142.
Braunwald et all. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine 8th edition.
Feigenbaum et al. Echocardiography. p
Oh et al. Basics in Echocardiography
Topol et al Manual of Cardiovascular Medicine. p