Chapter 283 - Aortic Valve Disease

Question 1

What is the prevalence of rheumatic valvular heart disease in the following locations: (1) Costa Rica; (2) China; (3) Worldwide.

Answer 1

(1) 1 per 100 000 school-age children
(2) 150 per 100 000
(3) 15-20 millions affected

Question 2

How many new cases and case fatalities are there per year due to rheumatic heart disease?

Answer 2

300 000 and 233 000, respectively.

Question 3

The mortality rate is higher in Southeast Asia worldwide.

True or False?

Answer 3

True.

~7,6 per 100 000

Question 4

How does one explain serious symptoms in youger patients in developing countries compared to developed countries?

Answer 4

“In economically deprived areas, tropical and subtropical climates (particularly on the Indian subcontinent), Central America, and the Middle East, rheumatic valvular disease progresses more rapidly than in more-developed nations and frequently causes serious symptoms in patients younger than 20 years of age. This accelerated natural history may be due to repeated infections with more virulent strains of rheumatogenic streptococci.”

Question 5

How many patients older than 75 years of age are affected with important left-sided valve disease?

Answer 5

12-13%

Question 6

Marfan’s disease is frequently associated with bicuspid (or its variants) valve.
True or False?

Answer 6

False.

Question 7

Since 2007, due to restricted use of antibiotic prophylaxis, the incidence of infective endocarditis is increasing.
True or False?

Answer 7

False.
“The incidence of infective endocarditis has increased with the aging of the population, the more widespread prevalence of vascular grafts and intracardiac deveices, the emergence of more virulent multi-drug-resistant microrganisms, and the growing epidemic of diabetes. The more restricted use of antibiotic phophylaxis since 2007 has thus far not been assocaited with an increase in incidence rates.”

Question 8

What is the prevalence of bicuspid aortic valve in the general population?

Answer 8

0,5-1,4%

Question 9

How frequent is aortic stenosis comparing to the other valve diseases? Is there gender differences regarding aortic stenosis?

Answer 9

“Aortic stenosis (AS) occurs in about one-fourth of all patients with chronic valvular heart diease; approximately 80% of adult patients with symptomic, valvular AS are male.”

Question 10

How frequent is bicuspid and unicuspid aortic valve leading to necessity to its replacement?

Answer 10

“A pathologic study of specimens removed at the time of aortic valve replacement for AS showed that 53% were bicuspid and 4% unicuspid.”

Question 11

Name the shared mechanisms of aortic valve deterioration and atherosclerosis. Are there shared risk factors?

Answer 11

“The process of aortic valve deterioration and calcification is not a passive one, but rather one that shares many features with vascular atherosclerosis, including endothelial dysfunction, lipid accumulation, inflammatory cell activation, cytokine release, and upregulation of severel signaling pathways.”

“Several traditional atherosclerotic risk factors have also been associated with the development and progression of calcific AS, including low-density lipoprotein (LDL) cholesterol, lipoprotein a (Lp[a]), diabetes mellitus, smoking, chronic kidney disease, and the metabolic syndrome.”

Question 12

How does one explain the bone matrix deposition in the diseased aortic valve?

Answer 12

“Eventually, valvular myofibroblasts differentiate phenotypically into osteoblasts and actively produce bone matrix proteins that allow for the deposition of calcium hydroxiapatite crystals.”

Question 13

Name the polimorphisms associated with increased risk for aortic stenosis and familial clusterning.

Answer 13

“Genetic polymorphisms involving the vitamin D receptor, the estrogen receptor in postmenopausal women, interleukin 10, and apolipoprotein E4 have been linked to the development of calcific AS, and a strong familial clustering of cases has been reported from western France.”

Question 14

Aortic valve sclerosis is a benign form of aortic stenosis.

True or False?

Answer 14

False.

Question 15

How frequent is aortic valve sclerosis in comparison to aortic stenosis and what are its consequences?

Answer 15

“The presence of aortic valve sclerosis (focal thickening and calcification of the leaflets not severe enough to cause obstruction) is associated with an excess risk of cardiovascular death and myocardial infarction (MI) among presons older than age 65. Approximately 30% of persons older than 65 years exhibit aortic valve sclerosis, wheareas 2% exhibit frank stenosis.”

Question 16

Rheumatic fever might lead to acquired bicuspid valve.

True or False?

Answer 16

True.
“Rheumatic disease of the aortic leaflets produces commissural fusion, sometimes resulting in a bicuspid-appearing valve.”

Question 17

Name the causes of aortic stenosis.

Answer 17

Congenital, degenerative calcific, rheumatic fever and radiation.

Question 18

Aortic stenosis due to rheumatic heart disease is rare without aortic regurgitation and mitral involvement.
True or False?

Answer 18

True.

Question 19

What is the prevalence of bicuspid aortic valve (BAV) in first-degree relatives? What is the inheritance pattern?

Answer 19

Approximately 10%.
“The inheritance patern appears to be autosomal dominant with incomplete penetrance, although some have questioned an X-lnked component as suggested by the prevalence of BAV among patients with Turner’s Syndrome.”

Question 20

Which of the following has a greater association with bicuspid aortic valve: aortic coartaction or aneurysm?

Answer 20

Aortic aneurysm of the ascending aorta.

Question 21

Which gene defects might be associated with bicuspid aortic valve?

Answer 21

NOTCH1, endothelial nitric oxide synthase and NKX2.5 have been implicated, although a single gene mutation doesn’t explain the majority of cases.

Question 22

Bicuspid aortic valve might be a component of Shone’s complex.
True or False?

Answer 22

True.

Question 23

How does one explain the hypertrophy rather then dilation of the left ventricle (LV) due to obstructive of its outflow?

Answer 23

“When severe obstruction is suddenly produced experimentally, the LV responds by dilation and reduction of stroke volume. However, in some patients, the obstruction may be present at birth and/or increase gradually over the course of many years, and LV contractile performance is maintained by the presence of concentric LV hypertrophy.”

Question 24

What is the equation for Laplace relation?

Answer 24

S = Pr/h
S = systolic wall stress
P = pressure
r = radius
h = wall thickness

Question 25

Name the echocardiographic findings that define a severe aortic valve stenosis.

Answer 25

"A mean systolic pressure gradient >40mmHg with a normal cardiac output or an effective aortic orifice area of approximately

Question 26

How come aortic stenosis might progress to low-flow, low-gradient stenosis?

Answer 26

"Late in the course, contractile function deteriorates because of afterload excess, the cardiac output and LV-aortic pressure gradient decline, and the mean left atrial, pulmonary artery, and right ventricular pressure rise."

Question 27

Ischemia might ensue in aortic stenosis only if there is concomitant coronary artery disease (CAD). True or False?

Answer 27

False. "The hypertrophied LV causes an increase in myocardial oxygen requirements. In addition, even in the absence of obstructive CAD, coronary blood flow is impaired to the extent that ischemia can be precipitated under conditions of excess demand. Capillary density is reduced relative to wall thickness, compressive forces are increased, and the elevated LV end-diastolic pressure reduces the coronary driving pressure. The subendocadium is especially vulnerable to ischemia by this mechanism."

Question 28

Bicupisd aortic valve (BAV) disease occurs one to two decades sooner than tricuspid AS, which occursby the sixth to eight decades. True or False?

Answer 28

True.

Question 29

Name the cardinal symptoms for aortic stenosis.

Answer 29

Exertional dyspnea, angina pectoris, and syncope.

Question 30

How does one explain dyspnea in aortic stenosis?

Answer 30

"Dyspnea results primarily frmo elevation of the pulmonary capillay pressure caused by elevations of LV diastolic pressures secondary to impaired relaxation and reduced LV compliance."

Question 31

Why is that most symptoms of aortic stenosis usually occur late in its course? Which ones are those?

Answer 31

"Because the cardiac output (CO) at rest is usually well maintained until late in the course, marked fatigability, weakness, peripheral cyanosis, cachexia, and other clinical manifestations of a low CO are usually not prominent until this stage is reached. Orthopnea, paroxysmal nocturnal dyspnea, and pulmonary edema, i.e., symptoms of LV failure, also occur only in the advanced stages of the disease. Severe pulmonary hypertension leading to RV failure and systemic venous hypertensio, hepatomegaly, AF, and tricuspid regurgitation are usually late findings in patients with isolated severe AS."

Question 32

Which valvulopathies might reduce or increase the transaortic pressure gradiente?

Answer 32

Mitral stenosis and aortic regurgitation, respectively.

Question 33

Since a wave might be proeminent in any cause of decreased right ventricular compliance, aortic stenosis might have a wave in the venous jugular pulse. True or False?

Answer 33

True. "In many patients, the a wave in the jugular venous pulse is accentuated. This results from the dimished distensibility of the RV cavity caused by bulging, hypertrophied interventricular septum."

Question 34

Where should one search for a thrill related to aortic stenosis?

Answer 34

"A systolic thrill may be present at the base of the heat to the right of the sternum when leaning forward or in the suprasternal notch."

Question 35

Which conditions are associated with a systolic ejection sound?

Answer 35

Mostly bicuspid aortic valve disease in young adults, but it might occur with pulmonic valve disease, dilation of the root of the great vessels, aswell as in heatlhy individuals.

Question 36

How does one explain the alteration of S2 as the aortic stenosis progresses?

Answer 36

"As AS increases in severity, LV systole may become prolonged so that aortic valve closure sound no longer precedes the pulmonic valve closure sound, and the two components may become synchronous, or aortic valve closure may even follow pulmonic valve closure, causing paradoxical splitting of S2."

Question 37

Which of the following occurs earlier in the course of aortic stenosis: S3 or S4?

Answer 37

S4. | "an S3 generally occurs late in the course, when the LV dilates and its systolic function becomes severely compromised."

Question 38

Describe the murmur associated with aortic stenosis.

Answer 38

"The murmur of AS is characteristically an ejection (mid) systolic murmur that commences shortly after the S1, increases in intensity to reach a peak toward the middle of ejection, and ends just before aortic valve closure. It is characteristically low-pitched, rough and rasping in character, and loudest at the base of the heart, most commonly in the second right intercostal space. It is transmitted upward along the carotid arteries. Occasionally it is transmitted downward to and along the apex, where it may be confused with systolic murmur of mitral regurgitation (Gallavardin effect)."

Question 39

Aortic stenosis' murmur is a perfect example how the intensity of a murmur does not correlate with its severity. Argue why.

Answer 39

"In almost all patients with severe obstruction and preserved cardiac output (CO), the murmur is at least grade III/IV. In patients with mild degress of obstruction or in those with severe stenosis with heart failure and low CO in whom the stroke volume and, therefore, the transvalvular flow rate are reduced, the murmur may be relatively soft and brief."

Question 40

What are the ECG findings in aortic stenosis?

Answer 40

LV hypertrophy and, in advanced cases, LV "strain (ST-segment depression and T-wave inversion in leads I, aVL and left precordial). There is no correlation between the ECG findings and the severity of obstruction.

Question 41

What are the echocardiographic cutoffs for aortic valve area?

Question 42

Name the most important echocardiographic marker indicative of aortic sclerosis.

Answer 42

Jet velocity less than 2,5m/s (peak gradient

Question 43

Due to the difficulties of evaluating low-flow, low-gradient, severe aortic stenosis with reduced ejection fraction one should use which test?

Answer 43

Doutamine stress echocardiography.

Question 44

In the face of uncertainty of the severity of aortic stenosis with reduced cardiac output, which test might be useful?

Answer 44

Quantitative analysis of the amout of aortic valve calcium with chest computed tomography.

Question 45

What would you expect to observe in a chest x-ray of a patient with advanced aortic stenosis?

Answer 45

"In later stages of the disease, as the LV dilates, there is increasing roentgenographic evidence of LV enlargement, pulmonary congestion, and enlargement of the left atria, pulmonary artery, and right heart chambers."

Question 46

Fluroscopic is more sensitive than chest x-ray to identify aortic valve calcification and thus, the absence of such calcification suggests that severe AS is not present. True or False?

Answer 46

True.

Question 47

Transaortic catheterization is associated with a risk of cerebral embolization in patients with aortic stenosis. True or False?

Answer 47

True.

Question 48

What are the main indications for catheterization?

Answer 48

"Catheterization is also useful in three distinct categories of patients: (1) patients with multivalvular disease, in whom the role played by each valvular deformity should be defined to aid in the planning of operative treatment; (2) young, asymptomatic patints with noncalcific congenital AS, to define the severity of obstruction to LV outflow, because operation or percutaneous aortic balloon valvuloplasty (PABV) may be indicated in these patients if severe AS is present, even in the absence of symptoms; and (3) patients in whom it is suspected that the obstruction to LV outflow may not be at the level of the aortic valve but rather at the sub- or supravalvular level."

Question 49

How frequent is concomitant coronary artery disease in adult patients who have indication for aortic valve replacement?

Answer 49

It exceeds 50%.

Question 50

Without surgery what is the average time until death if the patients has the following symptoms: (1) angina pectoris; (2) dyspnea; (3) congestive heart failure.

Answer 50

(1) angina pectoris - 3 years (2) dyspnea - 2 years (3) congestive heart failure - 1,5-2 years (in >80% of patients who died with AS, symptoms had existed for

Question 51

How frequent is sudden death associated with aortic stenosis in symptomatic and asymptomatic patients?

Answer 51

10-20% and less than 1% per year, respectively.

Question 52

The progression of aortic stenosis is associated with impaired echocardiographic criteria. How do you expect these to change along the years?

Answer 52

"annual reduction in valvve area averaging 0,1cm2 and annual increases in the peak jet velocity and mean valve gradient averaging 0,3m/s and 7mmHg, respectively."

Question 53

What is the rational use of statins in aortic stenosis?

Answer 53

"Retroscpective studies have shown that patients with degenerative calcific AS who receive HMG-CoA reductase inhibitors ("statins") exhibit slower progression of leaflet calcification and aortic valve area reduction that those who do not. However, randomized prospective studies with either high-dose atorvastatin or combined simvastatin/ezetimibe have failed to show a measurable efect on valve-related outcomes. The use of statin medications should continue to be driven by considerations regargind primary and secondary prevention of atherosclerotic cardiovascular disease events."

Question 54

What is the main indication for aortic valve replacement?

Answer 54

Symptomatic severe aortic stenosis. In this group it is also include those with systolic dysfunction (ejection fraction 5,5cm). "Patients with oderate or severe AS who are referred for coronary artery bypass grafting surgery should also have aortic valve replacement."

Question 55

What are the relative indications for aortic valve replacement?

Answer 55

"abnormal response to tradmill exercice, rapid progression of AS, especially when urgen access to medical care might be compromised; very severe AS, defined by an aortic valve jet velocity >5meters/s or mean gradient >60 mmHg and low operative risk; and excessive LV hypertrophy in the absence of systemic hypertension."

Question 56

How many patients with aortic stenosis have signs of functional impairment during exercise testing?

Answer 56

One-third.

Question 57

How high is the surgical mortality rate associated with the following conditions: (1) isolated aortic valve replacement (AVR) ; (2) AVR + coronary artery bypass; (3) AVR + mitral valve replacement; (4) low-flow, low-grade severe aortic stenosis with low ejection fraction.

Answer 57

(1) 2,3% (2) 4,2% (3) 8,8% (4) 15-20%

Question 58

``` The indications for surgery in a patient with moderate aortic stenosis (vmax 3m/s to 3,9m/s or mean gradient 20-39mmHg) belong to class IIa. True or False? ```

Answer 58

True.

Question 59

Name a class IIb indication for aortic valve replacement.

Answer 59

Asymptomatic severe aortic stenosis (vmax>4m/s or mean gradient>40mmHg) with velocity jet flux progression 0,3m/s per year and low surgical risk.

Question 60

What is the percentage of failure of aortic valve replacement using bioprosthetic valves?

Answer 60

Approximately 30% in 10 years.

Question 61

How many patients with mechanical aortic valve have hemorrhagic complications as consequence of anticoagulants?

Answer 61

Approximately 30%.

Question 62

In which occasion might one use homograft aortic valve replacement?

Answer 62

Aortic valve endocarditis.

Question 63

Describe the Ross procedure and its limitation.

Answer 63

"The Ross procedure involves replacement of the diseased aortic valve with the autologous pulmonic valve and implantation of a homograft in the native pulmonic position. Its use has declined considerably in the United States because of the technical complexity of the procedure and the incidence of late postoperative aortic root dilation and autograft failure with AR. There is also a low incidence of pulmonary homograft stenosis."

Question 64

Percutaneous Aortic Balloon Valvuloplasty (PABV) is restricted to congenital noncalcific AS. True or False?

Answer 64

False. "It is not commonly used as definitive therapy in adults with severe calcific AS because of a very high reestenosis rate (80% within 1 year) and the risk of procedural complications, but on occasion, it has been used successfully as a "brdige to operation" in patients with severe LV dysfunction and shock who are too ill to tolerate surgery."

Question 65

Which routes can be used for transcatheter aortic valve replacement?

Answer 65

Mostly transfemoral but trans-LV apical, subclavian, carotid and ascending aortic routes have also been used.

Question 66

Name three complications due to transcatheter aortic valve replacement.

Answer 66

Paravalvular aortic regurgitation (a risk factor for mortality over the next 2 years), early hazard stroke, and heart block (more frequently with self-expanding valve).

Question 67

Which two groups of diseases might lead to aortic regurgation (AR)?

Answer 67

"AR may be caused by primary valve disease or by primary aortic root disease."

Question 68

How many patients with bicuspid aortic valve will need surgery by 10-40 years of age?

Answer 68

20%.

Question 69

Which level of stenosis is frequently associated with aortic regurgitation?

Answer 69

"Membranous subaortic stenosis often leads to thickening and scarring of the aortic valve leaflets with secondary AR."

Question 70

How many patients with ventricular septal defect have an associated prolapsed aortic cusp?

Answer 70

15%.

Question 71

Name two examples of infections that lead to aortic regurgitation due to valve and aortic root involvement.

Answer 71

Infective endocarditis and syphilis, respectively.

Question 72

Concomitant aortic stenosis and aortic regurgitation occurs almost exclusively due to rheumatic or congenital aortic disease, excluding all the rarer forms of AR. True or False?

Answer 72

True.

Question 73

How does one explain the pahophysiology of aortic regurgitation due to primary aortic root disease?

Answer 73

"widening of the aortic annulus and separation of the aortic leaflets are responsible for the AR."

Question 74

Name the causes of aortic annulus dilation.

Answer 74

"Medial degeneration of the ascending aorta, which may or may not be associated with other manifestations of Marfan's syndrome; idiopathic dilation of the aorta; annuloaortic ectasia; osteogenesis imperfecta; and severe, chronic hypertension may all widen the aortic annulus and lead to progressive AR." Others causes include aortic retrograde dissection, syphilis and ankulosing spondylitis.

Question 75

Syphilis might lead to narrowing of the coronary ostia ans subsequent myocardial ischemia. True or False?

Answer 75

True.

Question 76

What is the major hemodynamic compensation in AR? Why is it so?

Answer 76

Increased preload. "The dilation and eccentric hypertrophy of the LV allow this chamber to eject a larger stroke volume without requiring any increase in the relative shortening of each myofibril. Therefore, severe AR may occur with a normal effective forward stroke volume and a normal LVEF (total [forward plus regurgitant] stroke volume/end-diastolic volume), together with an elevated LV end-diastolic pressure and volume."

Question 77

How does one explain the increased afterload due to aortic regurgitation?

Answer 77

"throuth the operation of Laplace's law, LV dilation increases the LV systolic tension required to develop any given level of systolic pressure."

Question 78

At autopsy, hearts of patients with chronic AR are among the larget encountered. True or False?

Answer 78

True.

Question 79

How do you explain the earlier closure of mitral valve due to acute AR?

Answer 79

"In patients with acute severe AR, the LV is unprepared for the regurgitant volume load. LV compliance is normal or reduced, and LV diastolic pressure rise rapidly, occasionally to levels >40mmHg. The LV pressure may exceed the left atrial pressure toward the end of diastole, and this reversed pressure gradient closes the mitral valve prematurely."

Question 80

Is there any association between aortic regurgitation and myocardial ischemia in patients who do not suffer from coronary artery disease?

Answer 80

Yes. "Myocardial ischemia may occur in patients with AR because myocardial oxygen requirements are elevated by LV dilation, hypertrophy, and elevated LV systolic tension, and coronary blood flow may be compromised. A large fraction of coronary blood flow occurs during diastole, when arterial pressure is low, thereby reducing coronary perfusion or driving pressure. This combination of increased oxygen demand and reduced supply may cause myocardial ischemia, particularly on the subendocardium, even in the absence of epicardial coronary artery disease."

Question 81

Define the following concepts: (1) Corrigan's pulse; (2) Quincke's pulse; (3) Traube's sign; (4) Duroziez's sign.

Answer 81

(1) rapidly rising (water-hammer pulse" which collapses suddenly as arterial pressure falls rapidly during late systole and diastole. (2) capillary pulsations due to an alternate flushing and paling of the skin at the root of the nail while pressure is applied to the tip of the nail. (3) booming "pistol-shot" sound heard of the femoral arteries. (4) to-and-fro murmur audible over the femoral artery as one lighly compresses it with a stethoscope. These are signs which might be present in aortic regurgitation.

Question 82

Which phase of the Korotkoff's sounds fairly corresponds to the true intraarterial diastolic pressure?

Answer 82

IV.

Question 83

How does one explain the progressive increasing in diastolic arterial pressure as the aortic regurgitation aggravates?

Answer 83

"As the diasease progresses and the LV end-diastolic pressure rises, the arterial diastolic pressure may actually rise as well, because the aortic diastolic pressure cannot fall below the LV end-diastolic pressure."

Question 84

Which pulses have an association with aortic regurgation?

Answer 84

Normal pulse, Corrigan's pulse and bisferiens pulse.

Question 85

What is the side where one hears aortic regurgitation due to disease of the aortic root with more intensity?

Answer 85

Right border side of the sternum.

Question 86

Name the parameters on echocardiography which are indicative of severe aortic regurgitation.

Answer 86

Central jet width ≥65% of the LV outflow tract Regurgitant fraction ≥50% Diastolic flow reversal in the proximal descending thoracic aorta

Question 87

What would you expecto to find in chest x-ray of a patient with knonw chronic severe aortic regurgitation?

Answer 87

"In chronic severe AR, the apex is discplaced downward and to the left in the frontal projection. In the left anterior oblique and lateral projections, the LV is displaced posteriorly and encroaches on the spine. When AR is caused by primary disease of the aortic root, aneurysmal dilation of the aorta may be noted, and the aorta may fill the retrosternal space in the lateral view. Echocardiography, cardiac MRI, and chest CT angiography are more sensitive than the chest x-ray for the detection of root and ascending aortic enlargement."

Question 88

Acute aortic regurgitation should be treated medically or bridged with intraaortic balloon counterpulsation until sugery. True or False?

Answer 88

False. Medical treatment is short-lived and operation is indicated urgently (within 24h). Intraaortic baloon counterpulsation is contraindicated.

Question 89

Which therapy would you use to retard the rate of aortic root enlargement in young patients with Marfan's syndrome and aortic root dilation?

Answer 89

Beta blockers and losartan.

Question 90

Beta blockers are contraindicated in chronic aortic regurgitation since they slow the heart rate, which leads to increasing of dyastole and subsequent regurgitant flow. True or False?

Answer 90

False. "The use of beta blockers in patients with valvular AR was previously felt to be relatively contraindicated due to concers that the resulting slowing of the heart rate would allow more time for diastolic regurgitation. More recent observational reports, however, suggest that beta blockers may provide functional benefit in patients with chronic AR.

Question 91

Which type of exercise should be avoided in severe aortic regurgitation, especially in those with aortopahy?

Answer 91

Isometric exercise.