Nagelhout Chp 25 - CV

Question 1

What is normal aortic valve area

Answer 1

2.5 - 3.5 cm2

Question 2

What is aortic stenosis and what are the causes :

Answer 2

Normal area is 2.5 - 3.5 cm2 . Reduction of 1/3 to 1/2 of the valve area means stenosis.
The narrowing results in obstruction of blood flow into the aorta .
Causes : 1) degeneration and calcification of the leaflets or
2) presence of bicuspid instead of tricuspid valve .

Question 3

Patient with aortic regurgitation , how will you select muscle relaxant for the patient ?

Answer 3

Goal in aortic regurgitation is to 1) maintain normal to elevates HR . Pancuronium/ vagolytic good choice . But the potential for sux to cause bradycardia should be considered before administration.

Question 4

What are the main anesthetic goal for patient with aortic regurgitation ?

Answer 4

HR : Normal to high with NSR
Preload : normal to high
Afterload : decreased
AVOID myocardial depression

Question 5

Describe the difference between ACUTE and CHRONIC aortic regurgitation and

Answer 5

Acute : LV has no time to compensate for increase in LV volume = LV failure, Pulmonary edema , CV collapse may ensue .
Chronic : no s/s shown for a long time , during normal activity the symptoms are not incapacitating . As long as the mitral valve patience does not result from LVH , pulmonary circulation is preserved. End stage AR = myocardial failure, decreased CO , high elevation in LVEDV and pulmonary edema

Question 6

What valve area and transvalular gradient is considered to be AS( Aortic Stenosis ) ?

Answer 6

N

Question 7

Normal SVR

Answer 7

800 to 1500 dynes/sec/cm5

Question 8

Normal Pulmonary vascular resistance is

Answer 8

50 to 150 dynes/sec/cm5

Question 9

What is severe aortic stenosis ?

Answer 9

Valve area less than 0.8 cm2

And transvalvular gradient > 50 mmHg

Question 10

What does increase DBP cause to AR?

Answer 10

Increases the backward pressure gradient which results in an increase in the proportion of SV that regurgitates back into the left ventricle

Question 11

MC conditions affecting the aortic leaflets that result in AR ?

Answer 11

Rheumatic Fever
Bicuspid aortic valve
Infective endocarditis
Use of anorexigenic ( diet ) drugs

Question 12

What is AR?

Answer 12

Failure of the aortic valve leaflet to velodrome properly due to disease of the aortic root or of the leaflets themselves

Question 13

Why is Afib or a junction alone rhythm so detrimental to a patient with aortic stenosis?

Answer 13

There is DECREASED pressure gradient between the LA and the LV bc of the aortic stenosis , and the atrial kick is needed to achieve adequate LV filling. Afib and Junctional rhythms knock out that extra 20 30 % that is needed and results in CHF and hypotension

Question 14

How is CO affected with aortic stenosis ?

Answer 14

At rest = CO is normal

Exertion = heart cannot increase CO = angina and dyspnea , even though there is no CAD

Question 15

How is myocardial oxygen and demand affected by aortic stenosis ?

Answer 15

The demand is INCREASED bc of concentric ventricular hypertrophy and
The supppy is DECREASED bc of intramyicardial vessels during systole restricts arterial flow to the myocardium.

Question 16

75% of patients with aortic stenosis die within

Answer 16

3 years if valve not replaced

Question 17

S/S of severe aortic stenosis

Answer 17

Classic triad :

Angina , Syncope , CHF

Question 18

Aortic regurgitation medical management ?

Answer 18

Reduce Afterload = reduce transvalvular gradient = easy forward flow out of LV => Hydralazine and nifedipine .

If acute exacerbation : Nitroprusside or Dobutamine can be used

Question 19

Patient has mild mitral stenosis, what will the heart do to compensate in order to maintain a good SV ? What factors can cause this compensation not to occur ?

Answer 19

The left atrial pressure will increase in an attempt to increase blood flow through the narrow valve .

If tachycardia or Afib the increase in atrial pressure will not work and will not be able to maintain the SV

Question 20

Mitral regurgitation vs Mitral stenosis .what are the goals for each ? How are they similar ?

Answer 20

MR = Increase HR and decrease afterload
MS= normal or decreased HR and normal afterload
In both: NSR, Maintain preload normal to increased levels , AVOID increase in PVR

Question 21

What meds are good for Mitral Regurgitation?

Answer 21

Ace I, BB, biventricular pacemaker

Question 22

Mitral regurgitation , what do you see in the PAOP waveform

Answer 22

A large V wave , the changes in the V wave amplitude help estimate changes int he degree of mitral regurgitation

Question 23

What Heart sound in Mitral regurgitation ?

Answer 23

Holosystolic Murmur radiating to the axilla

Question 24

Mitral regurgitation , when to do surgery ?

Answer 24

When EF is greater than 60 % or if patient is symptomatic

Question 25

How does SVR affect the pressure gradient in Mitral regurgitation?

Answer 25

Low SVR = decrease in regurgitant volume | High SVR = worse regurgitant volume

Question 26

What 3 factors determine the regurgitant volunteer in Mitral regurgitation ?

Answer 26

1) size of valve 2) HR 3) pressure gradient across valve

Question 27

What is the main problem in Mitral regurgitation?

Answer 27

Decrease in forward flow of blood ( SV) bc the volume is moving backwards into the left atrium during systole . ( holosystolic murmur )

Question 28

MCC of acute Mitral regurgitation?(5)

Answer 28

1) MI 2) Papillary muscle dysfunction 3) Chordae Tendinae rupture 4) Trauma to chest 5) Infectious endocarditis

Question 29

Primary anesthetic management objectives for patient with mitral stenosis ?

Answer 29

AVOID : hypovolemia , excessive Tberg = pulmonary edema N2O : be careful = it can increase PVR ( which we want to avoid ) Drugs causing tachycardia = Ketamine, Pancuronium is a no no, or be careful ! Meperidine can cause tachycardia only opioid that can do it :) otherwise give OPIODS to prevent intraop tachycardia , or increase depth of anesthesia or give a Beta Blocker Give phenylephrine or vasopressin if hypotension since they do not increase the HR Epidural is preferred over spinal bc ... less decrease in sympathetic activity with epidural !

Question 30

What is normal mitral valve area and when does symptoms occur ?

Answer 30

Normal is 4-6 cm2 | Symptoms when less than 1.5cm2

Question 31

How can mitral valve stenosis result in pulmonary edema ?

Answer 31

LA pressure increase >> transmitted into the pulmonary vasculature >> Pulmonary venous pressure > 25mmHg= leak into pulmonary interstitial space >> decreased pulmonary compliance >> increased Work of Breathing ( WOB )

Question 32

Heart sound in Mitral valve prolapse (MVP)?

Answer 32

Midsystolic click and a late systolic murmur

Question 33

How are LA, Pulmonary vasculature and RV affected by Mitral stenosis ?

Answer 33

Mitral valve small>> LA pressure increase > pulmonary blood volume and pressure increase >> right ventricular afterload increase>> RV hypertrophied and fails

Question 34

How is LV volume affected by mitral stenosis ?

Answer 34

Valve opening decreases>> pressure gradient across valve increases>> flow of blood through he opening decreases >>LV volume decreases .

Question 35

What cardiac conditions develop from Mitral stenosis ?

Answer 35

CHF Pulmonary HTN RV hypertrophy

Question 36

Mitral Stenosis is higher in ____. Over a period of 20 to 30 years ____cause the mitral valve leaflets to thicken , the commisure may fuse, the leaflets and annulus may become calcified.

Answer 36

Higher in female | Over 20 to 30 years , Rheumatic Fever

Question 37

MCC of Mitral Stenosis

Answer 37

Rheumatic Fever

Question 38

MC symptoms of valvular disorders in general ?

Answer 38

1) CHF 2) Dysrhythmia 3) Syncope 4) Angina

Question 39

What is mixed valvular disorder ?

Answer 39

It is a combination of stenosis , and insufficiency. One usually more dominant than the other

Question 40

Heart sound in Mitral Stenosis ?

Answer 40

Opening Snap in early diastole and | Rumbling diastolic murmur heard best at the axilla or apex

Question 41

What are the risk factors for developing aortic stenosis ?

Answer 41

Simalar to those factors for Ischemic Heart Disease : | HTN , HLD, DM, Smoking, and male gender

Question 42

What is a the anesthetic choice in Mitral regurgitation .

Answer 42

1) Neuraxial is NOT contraindicated BUT : dramatic decrease in sympathetic activity = consider that super low bp may happen General anesthesia is the anesthetic of choice .

Question 43

MVP is

Answer 43

When 1 or both mitral leaflets dip into the the left atrium during systole . It can occur with or without Mitral regurgitation.

Question 44

What factors decrease the degree of prolapse in MVP ?

Answer 44

Any factor that maintain a LARGER ventricular volume = decrease degree of prolapse . HTN , Vasoconstriction, drug induced myocardial depression, increased preload = decrease degree of prolapse Never thought HTN could be good for something in the heart *

Question 45

What factors will increase the prolapse ?

Answer 45

The more the ventricle empties the more the prolapse : | Increase LV contractility or decrease SVR = worse prolapse !

Question 46

S/S of MVP

Answer 46

Although many are asymptotic: 1) chest pain 2) MR 3) Infectious endocarditis 4) embolism 5) even sudden cardiac death

Question 47

What disorders exhibit high indidence of MVP?

Answer 47

``` Marfan Lupus Rheumatic carditis Thyrotoxicosis Myocarditis ```

Question 48

MVP is more common in

Answer 48

Young females

Question 49

S1 happens then

Answer 49

Ventricular pressures are greater than Atrial pressures , closing the tricuspid and mitral valves

Question 50

SVR is the

Answer 50

Load that the cardiac muscles of the ventricle encounter after contracting starts

Question 51

What is Eisenmeger’s syndrome ?

Answer 51

Is a reversal of the left-to-right intracardiac shunt due to increase in the pulmonary vascular resistance. Once the PVR = or > than SVR the shunts reverses to a right-to-left shunt.

Question 52

Medical treatment of PDAs

Answer 52

Indomethacin ( a nonselective cycloogenase Inhibitor) is the first line therapy