Aortic Stenosis

Question 1

Causes of aortic stenosis

Answer 1

Congenital bicuspid deformation > Aging calcification

Rheumatic fever

Question 2

Risk factors for calcification with aortic stenosis

Answer 2

HTN
HLD
(Same as CAD)

Question 3

Symptoms of aortic stenosis

Answer 3

Loud systolic murmur
Classic triad: angina, syncope, CHF
Sudden cardiac death

Question 4

Why is CPR challenging with aortic stenosis?

Answer 4

Difficult to open aortic valve limits forward flow

Question 5

The SV in aortic stenosis is described as?

Answer 5

Fixed

Question 6

Mean pressure gradient higher than ____ is considered severe aortic stenosis

Answer 6

50 mmHg

Question 7

Peak pressure gradient higher than ___ is considered severe aortic stenosis

Answer 7

80 mmHg

Question 8

What is secondary compensation with aortic stenosis?

Answer 8

Increased blood volume
Increased LV systolic pressure
Concentric ventricular hypertrophy

Question 9

Concentric vs Eccentric hypertrophy

Answer 9

Concentric: Increased wall thickness, chamber size is unchanged or smaller
Eccentric: Decrease in wall thickness, chamber size increased

Question 10

What are the consequences of compensation with aortic stenosis?

Answer 10

Hypertrophy of the LV > low ventricular compliance

• ventricle is stiffer
• more difficult to fill
• pressures will increase without the usual increase in volume

Question 11

Describe the relationship between PCWP and LVEDP with LVEDV in aortic stenosis

Answer 11

PCWP over estimates LVEDV

-pressure reading over estimates volume because low compliance = higher pressure without accompanying volume

Question 12

What kind of preload is needed with aortic stenosis?

Answer 12

Needs more preload for adequate SV

-PCWP needs to be higher than expected in order to achieve SV

Question 13

What is very important with aortic stenosis?

Answer 13

Atrial kick

Question 14

How much does atrial kick supply with aortic stenosis?

Answer 14

40% instead of the normal 20%

Question 15

Hypertrophy puts patient at risk for ischemia why?

Answer 15

Hypertrophic muscle increases myocardial oxygen demand

Question 16

Describe the situation of O2 supply and demand with aortic stenosis

Answer 16

Hypertrophic muscle increases demand
Higher ventricular systolic pressure increases demand

Supply is decreased due to higher LVEDP decreasing CPP

Question 17

What is the rhythm and HR anesthesia goal for aortic stenosis?

Answer 17

Maintain SR
-loss of atrial kick impacts SV and BP
Keep HR between 70 and 80
-SV is fixed low HR decreases CO
-High HR risks ischemia

Question 18

What is the goal with SVR and aortic stenosis

Answer 18

Maintain SVR

• decreases in SVR > low DBP and CPP
• increased SVR > decreases in SV and CO

Question 19

What is the goal with preload in aortic stenosis?

Answer 19

Maintain or increase preload

• noncompliant ventricle requires higher filling volume
• LVEDP will look height than actual LVEDV

Question 20

What is the #1 anesthetic goal with aortic stenosis?

Answer 20

Maintain SVR

Question 21

Describe the use of regional anesthesia with aortic stenosis

Answer 21

Spinal are relatively contraindicated because it will drop SVR
Epidurals less so

Question 22

What is the AHA guideline for preop ABX with valve disease for endocarditis?

Answer 22

Dental procedures
Infected respiratory tract, skin, musculoskeletal, GI, GU
Cardiac surgery

Question 23

What technique makes SVR more controllable with aortic stenosis?

Answer 23

General

Question 24

Describe drug choice with aortic stenosis

Answer 24

Induce with any drug keeping HR and SVR stable

Muscle relaxant with CV stability

Question 25

How is HTN best treat with AS?

Answer 25

Best to give more anesthetic than a vasodilator

Question 26

How is HoTN best treated with AS?

Answer 26

Immediately and aggressively with phenylephrine

Question 27

Monitoring during anesthesia with AS?

Answer 27

5 lead EKG
-ischemia risk
Special considerations for PAC
-insertion dysrhythmias more problematic
-LV compliance Algiers relationship of PCWP to actual preload volume