Aortic Valve Disease questions

Question 1

How is severity of aortic stenosis quantified

Answer 1

1) Planimetry–short axis view on 2D echo
2) Continuity equation–total flow of blood that passes through the LVOT is the same as the total flow passing through the aortic valve
3) Gorlin equation– AVA = CO/44.3 x HR x LVET (left ventricle ejection time) x square root of mean gradient.

Question 2

3 main causes of aortic stenosis and the pathological features of the disease

Answer 2

1) Rheumatic fever— commissural fusion with leaflet thickening and fibrosis, resulting in triangular aortic valve orifice
2) Calcific degeneration— begins at the base of the cusps and progresses toward the leaflet edges with the commissures remaining open
3) Bicuspid aortic valve— cusps are prone to earlier progressive thickening and calcification with age

Question 3

Describe pathological findings of calcific degeneration

Answer 3

Masses of lipocalcification lying on the aortic side of the valve consisting of

1) inflammatory cell infiltrate (macrophages, T lymphocytes
2) lipids (LDL and lipoprotein A)
3) Microscoptic calcification
4) other proteins

Question 4

What are signs of aortic stenosis

Answer 4

Pulsus tardus (slow-rising pulse)
Palsus parvus (small amplitude pulse) 
Single heart sound: A2 component is diminished due to calcification and stiffening 
Paradoxical splitting of the second heart sound (delayed A2)
Fourth heart sound---pre-systolic thrust generated from atrial contraction into a hypertrophied and non-compliant left ventricle 
Crescendo-decrescendo systolic murmur causes by turbulent flow-(not pansystolic)
Late peaking of AS murmur indicates its severity rather then intensity

Question 5

What is low-flow, low gradient aortic stenosis? how is it managed

Answer 5

Patients with low ejection fraction of <40%, a mean gradient of < 30 mmHg, and a calculated aortic vavle area of < 1.0 cm2

Dobutamine stress echocardiography, 5 -20 ug/kg/min of dobutamine administered in increments of 5 ug every 5 minutes and assesses for increase peak pressure gradient and change in EOA.

Question 6

What are physical signs of Aortic Regurgitation

Answer 6

Widened pulse pressure
Duroziez’s sign-systolic and diastolic murmur audible over femoral arteries
Quinke’s sign-pulsation in the capillary membranes of the fingertips
Traube’s sign-pistol shot sound audible over the femoral artery
De Musset’s sign-head bobbing with a collapsing pulse
Corrigans pulse–water-hammer collapsing pulse
Mueller’s sign–pulsation of the uvula
Hills sign–SBP in the leg greater then SBP in the arm by at least 20 mmHg.
3rd heart sound loudest at apex
Decrescendo diastolic murmur hear best with patient exhaling
Austin Flint–low pitched diastolic murmur occurs because of turbulence across the mitral valve

Question 7

List surgical options for patients with a small aortic root

Answer 7

Implanting a valve prosthesis with an improved EOA
stentless valve
small sewing ring valve (CE perimount magna)
surpa-annular
Aortic root enlargement with bovine pericardial patch
Aortic annular enlargement
Aortic root replacement
Apico-Aortic valved conduit

Question 8

What is Freedom from structural valve deterioration for the different aortic valve prostheses
For patients 70 years old at 15 years

Answer 8

1) Mechanical valve 97%
2) Aortic valve homograft 85%
3) Bovine pericardial valve 85%
4) Porcine bioprosthesis 80%
5) stentless bioprosthesis 80%
6) pulmonary autograft (Ross) 74% for the aortic valve and 80% for the pulmonary valve

Question 9

Structural valve deterioration (SVD) in bioprosthetic valves based on age at 10 years

Answer 9

40% in patients aged 0 - 40 years
30% in patients aged 40 to 69
10% in patients aged > 70 years

Question 10

Describe other lesions associated with BAV

Answer 10

Short left main stem coronary artery
A left dominant coronary artery circulation
An anomalous position of the coronary ostia
aortopathy
coarctation of the aorta
earlier onset of aortic stenosis

Histological analysis reveals cystic medial necrosis, reduced fibrilin-1 production and elastin fragmentation

Question 11

List factors to consider when pregnant pt with a mechanical valve insitu

Answer 11

Warfarin crosses the placenta and increases risks of abortion, prematurity, and stillbirth
Warfarin associated with embryopathy in 5-10% of pts but is lower if dose <5mg/day.
Heparin dose not cross placenta but may induce bleeding at uteroplacental junction
Strategy:
warfarin during weeks 1-6
Unfractionated heparin during 6 -12 weeks
warfarin 12 to 36 weeks
UFH from week 36
stop heparin before delivery

Question 12

How can atherosclerosis of aorta be classified

Answer 12

Type I: Circumferential calcification or “porcelain aorta” Easily palpable
Type II: Diffuse intimal thickening with ragged friable edges. Unreliable to manual palpation, easy to identify by the TEE or epiaortic scan.
Type III: intramural liquid debris. the most difficult to palpation on TEE.

Question 13

What is natural history of untreated aortic stenosis

Answer 13

Angina –5 years
Syncope–3 years
dyspnea–2 years

Question 14

What are two posterior root enlargement procedures

Answer 14

Nicks aortic annuloplasty: incision through the middle of non-coronary sinus

Manougian’s aortic annuloplasty: incision pass through the commissure between the left and non-coronary sinuses and onto the anterior leaflet of the mitral valve

Question 15

What is natural history of patients with untreated AI

Answer 15

6% of asymptomatic patients with good left ventricular function either become symptomatic develop left ventricular dysfunction per year

25% of asymptomatic patients with left ventricular dysfunction develop symptoms per year

symptomatic patients have a 10% mortality per year

Question 16

How is aortic regurgitation quantified

Answer 16

mild	 mod      Severe
Jet width					<25	 25-65	> 65
Vena contracta			 0.6
Regurgitant fraction%		<30	30-50	> 50
Regurgitant volume			<30	30-60	>60
Effective regurgitant orifice 	<0.1	0.1-0.3	 >0.3

Question 17

What structures are at risk during aortic valve surgery

Answer 17

Anterior mitral valve leaflet (beneath the non-coronary and left coronary cusps)
Membranous septum: (beneath the non-coronary and right coronary cusps)
Bundle of HIS: (beneath the commissure between the non-coronary and right coronary cusps)
Left and right coronary ostia

Question 18

What are the surgical approaches to the aortic valve

Answer 18

Oblique aortotomy (J-shaped)
transverse aortotomy
Greater curve aortotomy, which can be combined with an aortoplasty to reduce the size of a moderately enlarged ascending aorta

Question 19

What are different methods of implanting an aortic valve prosthesis

Answer 19

Interrupted sutures technique, reduced risk of paravalvular leak
Everting suture–place the prosthetic valve in an intra-annular position thereby reducing the relative effective orifice area (EOA) of the annulus allowing a smaller valve to be implanted
Non-everting sutures-place the prosthetic valve in a supra-annular position, thereby increasing the effective orifice area of the annulus, allowing a larger valve to be implanted, relative to the everting suture technique.

Semi-continuous technique, which is faster, but has theoretical increased risk of PV leak.

Question 20

What is Marfan syndrom

Answer 20

Autosomal dominant variably penetrant inherited disorder; prevalence is 1 in 5000

Mutation in the gene that endocodes fibrillin-1 on chromosome 15

Question 21

What are the diagnostic (Ghent) criteria for marfan

Answer 21

Family history 
Mutation of FBN1
Cardiovascular
	Aortic root dilation 
	Dissection of ascending aorta
 		mitral valve prolapse
		calcification of the mitral valve
		dilation of the pulmonary artery
		dilation or dissection of the descending aorta
Ocular
	ectopia lentis
		flat cornea
		myopia
		elongated globe
Skeletal
	pectus excavatum
	pectus carinatum
	pes plans
	 thumb sign
	scoloisis. or spondyloisthesis 
	arm span > 1.05
pulmonary 
	apical bulla/spontaneous pneumothorax
skin
	unexplained stretch marks/recurrent incisional hernia

Question 22

What is Loeys-Dietz syndrome

Answer 22

mutations in TGF beta receptors 1 and 2
similar to that of Marfan or more drastic associated with dissection in children.
characterized by the triad of
hypertelorism
bifid uvula/cleft palate
generalized arterial tortuosity with wide spread vascular aneurysm and dissection

Question 23

What is Vascular Ehlers-Danlos syndrome

Answer 23

rare autosomal dominant inherited disorder of the connective tissue resulting in COL3A1 gene encoding of type III collagen

spontaneous rupture without dissection of large and medium-caliber arteries accounts for most deaths

Aortic root dilation is common

Question 24

Name other causes of aneusrym disease of aorta

Answer 24

Athersclerotic
Infectious (syphilitic) 
aortitits 
	giant cell 
Ankylosing spondylitis
Reiters sydrome
psoriatic artheritis
polyarteritis nodosa
Behcet's disease

Question 25

What is natural history of biscuspid aortic valve

Answer 25

Mayo clinic showed at 15 year follow up the 20 year survival was similar to that of the general population but the incidence of surgery on the aortic valve and/or ascending aorta was 27% and the total adverse cardiovascular events was 42%.

Question 26

What are rates of rupture based on size of ascending aortic aneurysms

Answer 26

``` Median size of ascending aortic aneursym at time of rupture was 5.9 cm for all pt incidence of rupture < 4cm was 8% 9.5% for 4 to 4.9cm 17.8% for 5 o 5.9 27.9% for >6 cm ``` This was over a 29.4 month period (Coady, total of 370 patients)

Question 27

What are the differences of generations for stented prostheses valves

Answer 27

First generation: preserved in high-pressure and were placed in the annular position) Second generation: treated with low or zero pressure fixation , several placed in supra-annuluar position Third generation: zero or low pressure, antimineralization (reduce material fatigue and calcium), stent have a lower profile, flexible, thinner, and scalloped.

Question 28

How does Glutaraldehyde work?

Answer 28

Cross-linking collagen fibers to reduce tissue antigenicity. Ameliorates in vivo enzymatic degradation and causes the loss of cell viability, thereby preventing extracellular matrix turnover.

Question 29

How is sizing of company valves determined

Answer 29

Label sizes refer to either the internal or the external diameter of the stent, the external diameter of the sewing cuff or the maximal opening diameter of the valve leaflets

Question 30

Describe the anterior approach for root enlargement

Answer 30

Described by Konno in 1975 Used when you need more then 4 sizes of increase Longitudinal incision in aorta and extended to the right coronary sinus of valsalva and then through the anterior wall of the right ventricle to open the right ventricular outflow tract the ventricular septum is incised.

Question 31

Indicate the current recommendations to the use of warfarin and target INR

Answer 31

AVR with mechanincal valve and NSR = 2.0 to 3.0 AVR biological with atrial fribrillation = 2.0 Mitral valve replacement with tissue valve 2.5 to 3.5 Mitral valve replacement with mechanical valve = 2.5 to 3.5

Question 32

List seven complications of valvular substitutes

Answer 32

``` Thrombosis Embolism Hemolysis Strctural valve failure periprosthetic leak Anticoagulant-related hemorrhage Prosthetic valve endocarditis Hemodynamic valve failure ```

Question 33

What is patient prosthesis mismatch

Answer 33

Defined as the EOA of an implanted prosthetic valve being too small relative to the patients body surface area. It is sub-classified by a prosthetic EOAI (EOA indexed) a) mild > 0.85 cm2/m2 b) moderate 0.65 cm2/m2---0.85 cm2/m2/ c) severe < 0.65 cm2/m2 Leads to persistently high transvalvular pressure gradients, reduced left ventricular mass regression, reduced symptom improvement and reduced exercise tolerance, there is controversary regarding the effects of PPM on short and long-term mortality.

Question 34

At what indexed effective orifice area can PPM mismatch theoretically occur?

Answer 34

< 0.85cm/m2

Question 35

For pts with PPM what percentage will be expected to develop symptoms

Answer 35

20%

Question 36

What is clinical impact of PPM

Answer 36

worse hemodynamics lesser regression of LV hypertrophy more cardiac events Debate of short and long term survival---especially if LV dysfunction is present

Question 37

What is clinical impact of PPM in the aortic position

Answer 37

``` less improvement in symptoms and functional class impaired exercise capacity less regression of LV hypertropy less improvement in coronary reserve more adverse cardiac events ``` The impact on PPM is more pronouced in younger, those with poor LV function.

Question 38

Describe the incision in the aorta and heart to perform a Nicks

Answer 38

An oblique incision in the anterior ascending aorta steers inferiorly and to the right and crosses the aortic annulus in the middle of the noncoronary sinus and extends for a variable distance into the base of the anterior mitral leaflet

Question 39

How does a Manouguina root enlargement differ from the Nicks procedures

Answer 39

The incision crosses the annulus through the commissure between the left and the noncoronary sinus Down onto the anterior leaflet of the mitral valve May require a patch

Question 40

How much can the aortic annulus diameter be enlarged with Nicks and Manougian

Answer 40

Nicks 2 mm Manougian up to 4 mm

Question 41

Echocardiographer tells you that the peak velocity of blood flow across the aortic valve of a pt is 4meters/second. What is peak gradient? How did you arrive at this estimated value

Answer 41

Estimated peak gradient = 64mmHg estimated by the Gorlin equation: aortic valve gradient = 4v2 (v = peak velocity of blood flow across the aortic valve)

Question 42

What are 3 indications for surgery in asymptomatic adults with chronic severe AI

Answer 42

Left ventricular systolic dysfunction (EF < 50%) associated cardiovascular disease requiring surgery such as coronary artery disease enlarging left ventricule (LVEDD 70-75mm and ESDD 50-55mm)

Question 43

List 3 absolute contraindications to the Ross procedure

Answer 43

Marfan and other collagen disorders Auto-immune or other systemic disorders (Libman-sacks, rheumatoid arthritis) Anatomical abnormality on the pulmonic valve Relative Multiple valve disease Poor LV function Severe aortic annular dilation

Question 44

List absolute contraindications to Ross procedure

Answer 44

Marfan's disease Bicuspid or quadricuspid pulmonary valve Immunological disorders fenestrated pulmonary valve

Question 45

List relative contraindications to Ross procedure

Answer 45

Aortic annulus > 30 mm Bicuspid aortic valve disparity between aortic annulus and pulmonary annulus (> 2mm in size)

Question 46

55 year old male with stenotic bicuspid aortic valve. Ascending aorta is 6 cm. Coronary artery ostia appear to be displaced at least 2 cm from aortic annulus. What operation would recommend?

Answer 46

Replacement of aortic valve, replacement of ascending aorta and reimplantation of coronary ostia (ie, modified bentall procedure)

Question 47

Describe Konno (Konno-Rastan Aortoventriculoplasty)

Answer 47

vertical aortotomy to the L of RCA, through annulus in RCC Annulus of RVV incised to the L of the nadir and extended into interventricular septum separate incision in infundibulus of RV to guide septal incision posterior annulus sutures placed and valve tied down patch of pericardium sewn into the IVS defect and brought up to anterior aspect of mechanical valve Patch sewn to sewing ring of valve and then patch carried distally to enalrge and close the aorta RVOT defect close with fixed pericardium

Question 48

How do you calculate BSA

Answer 48

Mosteller formula = sqrt [ht (cm) x wt (kg)/3600] average for women 1.6 to 1.6 men 1.9m2

Question 49

What is long outcomes from AVR in Carpentier edwards pericardial valve

Answer 49

Freedom from structural valve degeneration at 15 year was 34.7% in patients < 65 89% in patients 65 to 75 years of age 99.5% in patients more than 75 years Mccure and Cohn from Brigham and Womens hospital 2010, Annals of thoracic surgery 2010

Question 50

What is pseudo aortic stenosis

Answer 50

A low calculated AVA, which is artificial because flow is too low (to open a mildly or moderatly diseased aortic valve) or an eorr in the calculated AVA TTE can underestmate the LVOT by as much as 17% because of its shape. Use 3D echo, CT or MRI obtain more accurate measure of aortic annulus.

Question 51

What are potential reactions from Dobutamine stress Echo

Answer 51

True AS--increase in peak velocity, MPG, and no change in AVA Pseduo-AS--increase in AVA by > 0.3cm2 with no significant change in MPG, and peak velocity Absence of contractile reserve did not help distinguish between the two groups because there was no change in forward stroke volume. Presence of contractile reserve is defined ass increase in peak velocity of 0.6m/s, stroke volume > 20% and MPG > 10 mmHg with Dobutamine.

Question 52

What does contractile reserve infer about mortality post AVR for low flow low gradient AS

Answer 52

5% mortality if you have contractile reserve VS 32% mortality if you do not

Question 53

If you have no contractile reserve in AS what is the relationship compared to medical therapy

Answer 53

Tibroiilloy showed 5 year survival of AVR on medical therapy to be 54% and 13% if you just stayed on meds...despite a 22% mortality Therefore, absence of contractile reserve should not preclude AVR even though it clearly portends a higher operative mortality.

Question 54

What is natural history of AS in terms of increase in gradient

Answer 54

The aortic valve gradient increases by 0 to 15 mmgHg per year the AVA decreases by 0.12cm2/year

Question 55

What are qualitative feature of AI

Answer 55

mild mod severe Angiographic 1+ 2+ 3-4+ Color dopp jet width 65% vena contracta 0.6

Question 56

Name one component that contributes to anti-calcifification in bioprosthetic valves

Answer 56

alpha-amino acid (AOA)--a compound from oleic acid.

Question 57

List indications for stentless valves

Answer 57

1) Aortic root disease when bioprosthesis is desired 2) Aortic dissection, (when valve need a replacement). Extensive dissection in the sinuses of valsalva is easily handled with a stentless bioprothetic 3) Endocarditis--allows maximal debridement

Question 58

Describe durability outcomes of stentless AVR (Toronto SPV) ?

Answer 58

9 years the Freedom from SVG was 90% and there was actual improvement in survival. 12 years there was 69% freedom from SVG and only 52% in those < 65 years of age Freedom from moderate to severe AI was 48%

Question 59

What is rate of sudden death with severe AS (asymptomatic)

Answer 59

1%/year

Question 60

What are the physical findings of severe AS

Answer 60

Late-peaking creseendo-descresendo systolic murmour radiating to the carotids Single A2 heart sound delay and reduced amplitude of carotid pulse *severe AS is very unlikley if you hear splitting of S2*

Question 61

What addition test can be performed in a patient with severe asymptomatic AS

Answer 61

Exercise stress testing | Brain natriuretic peptide

Question 62

What are important BNP cut off for severe AS

Answer 62

BNP and ANP are endogenous hormones with diuretic and peripheral regulatory actions BNP is produced predominatly from stretched LV in response to wall stress if the BNP level is around 100 the AVA is usually < 1.0 An NYHA class II pt would have a BNP around 100 if the BNP is 25 then AVA is usually > 1.0. it's the 25 to 100 number which is interesting

Question 63

What is natural history of AI

Answer 63

Symptomatic pts have a 10%/year mortality Progression to cardiac symptoms in pts with LV systolic dysfunction 25% Asymptomatic rate of sudden death is 0.2% Asymptomatic progression to LV dysfunction in <3.5% Asymptomatic if LVESD is >50 to LV systolic dysfunction is 19%

Question 64

What is Laplace Law

Answer 64

Relates how left ventricular hypertrophy occurs as compensatory mechanism to reduce will stress WS (wall stress) = P (pressure) x r (radius)/ 2 x Th (Left ventricular wall thickness)