Aortic Regurgitation

Question 1

What are some causes of chronic aortic regurgitation?

Answer 1

Congenital bicuspid deformation
Associated diseases: Marfan’s, connective tissue disease, etc
Rheumatic fever

Question 2

What kinds of things cause acute aortic regurgitation?

Answer 2

Endocarditis
Trauma
Aneurysm dissection

Question 3

What are they symptoms associated with aortic regurgitation?

Answer 3

Diastolic murmur

Decreased DBP

Question 4

What is the magnitude of regurgitation influenced by?

Answer 4

HR

SVR

Question 5

Forward flow with AR is?

Answer 5

decreased net forward flow

Question 6

How is regurgitation classified?

Answer 6

By the regurgitant fraction of SV

Question 7

What is the regurgitant fraction of mild AR?

Answer 7

Under 40%

Question 8

What is the regurgitant fraction for severe AR?

Answer 8

Over 60%

Question 9

What are the secondary compensation mechanisms with AR?

Answer 9

Increased blood volume

Eccentric ventricular hypertrophy

Question 10

What is eccentric hypertrophy?

Answer 10

Decrease in wall thickness

Increase in chamber size

Question 11

What occurs due to the compensation associated with AR?

Answer 11

Ventricular compliance increases because there is an increase in volume

Question 12

What ultimately occurs from years of AR?

Answer 12

LV failure > now LVEDP does increase > pulmonary edema

Question 13

Describe chronic vs acute AR

Answer 13

With chronic AR ventricle has time to hypertrophy and dilate for long term compensation that can eventually lead to LV failure.
With acute AR there is sudden LV overload without time for compensation and immediate LV failure is likely

Question 14

Describe myocardial oxygen supply and demand with AR

Answer 14

Demand is increased due to increased mass

Supply is decreased because the lower DBP decreases CPP

Question 15

What is the HR anesthetic goal?

Answer 15

Modest increase in HR

-this allows less time for diastolic regurgitation

Question 16

What is the proload goal with AR?

Answer 16

Maintain or increase preload

Question 17

What is the SVR goal with AR?

Answer 17

Decrease SVR

-less resistance promotes forward flow

Question 18

What is the contractile goal with AR?

Answer 18

Maintain contractility

-keeps volume moving forward

Question 19

What anesthetic technique is more manageable with AR?

Answer 19

General

Question 20

Induction drugs with AR?

Answer 20

Any

-ketamine will increase HR (good), but also increase SVR (bad)

Question 21

Muscle relaxants with AR?

Answer 21

Any

Pancuronium may increase HR (good)

Question 22

Volatile anesthetic with AR?

Answer 22

Isoflurane is the ideal
-strongest vasodilator (good)
-modest increase in HR (good)
SEVO and DES are good too

Question 23

What with anesthesia will increase the likelihood of LV failure with AR?

Answer 23

Myocardial depression
-agents
Increased afterload
-vasoconstriction

Question 24

How should you treat LV failure and increasing LVEDP with AR?

Answer 24

Reduce afterload with Nipride
-arterial dilator
If that’s not enough Inotropes
-Dobutamine

Question 25

How could a PAC help monitor a pt with AR?

Answer 25

Adequate preload is essential to maintain net forward volume
Too much vasodilation risks preload reduction
Helps find optimal filling pressure

Question 26

In general which aortic disease leads to more hemodynamic changes?

Answer 26

Stenosis

Question 27

Monitoring AR during anesthesia

Answer 27

5 lead EKG
-ischemia risk
PAC (+/-)
-monitor preload, optimal filling pressure