Valvular Disease

Question 1

Drug therapy for valvular disease

Answer 1

1) Digitalis (Digoxin)
- Given to increase contractility and low the ventricular response in those with a-fib

2) Diuretics
- May be given for excess intravascular fluid volume, but resultant hypokalemia can place at risk for digitalis toxicity

3) Prophylactic Antibx
- Recommended for the protection against the development of infective endocarditis

Question 2

Tests for valvular heart disease

Answer 2

1) Doppler Echo
2) Cardiac cath to measure the severity of valvular heart disease
3) ABG may show low O2 and signs of VQ mismatch

Question 3

Patho of mitral stenosis

Answer 3

Usually due to fusion of the mitral valve leaflets at the commissures during the healing process of acute rheumatic fever

Normal valve area is 4-6cm2
When valve area is < 1 cm2, a mean left atrial pressure of 25mmHg is needed to push past the valve and maintain an adequate CO

Question 4

Adverse effects that may happen d/t mitral stenosis

Answer 4

Left atrial enlargement
- Predisposes to a-fib
A-fib can cause thromboemboli formation
- Pt will be on anticoagulants
Blood gets backed up. Pt will experience dyspnea on exertion when CO is increased.

Question 5

Severe MS can lead to

Answer 5

CHF

Question 6

Overall goal for mitral stenosis disease in anesthesia

Answer 6

Slow, tight, full

Slow: Avoid tachycardia or a-fib with RVR

Tight: Tight control of blood volume. Avoid marked increases in blood volume from over-transfusion or head-down positions. Tight fluid administration, give blood or colloids.

Full: Maintain preload. We need adequate pressures to overcome the stenosed valve. Large decreases in SVR will drop preload. IAs will drop SVR a lot.

Also don’t do anything that will increase PVR and cause RV failure.

Question 7

Induction with valvular disease

Answer 7

Etomidate is probably best. We want to avoid things that increase HR (ketamine) or abruptly decrease SVR (propofol).

Slow, tight, full mothafucka

Question 8

Patho of mitral regurgitation

Answer 8

Usually d/t rheumatic fever and is almost always associated with mitral stenosis.

Causes fluid overload in the LA by retrograde flow during ventricular contraction

Question 9

Appearance of mitral regurgitation on PAOP tracing

Answer 9

Reguritant flow causes V wave on PAOP

Size of the V wave correlates with the magnitude of regurgitant flow

Question 10

Anesthetic goals in mitral regurgitation

Answer 10

Fast, full, forward

Fast: Avoid sudden decreases in HR, which allows more time for blood to flow backwards

Full: Avoid sudden increases in SVR, which would promote backward flow

Forward: minimize myocardial depression

Question 11

Patho of aortic stenosis

Answer 11

If purely AS, it’s usually d/t calcification of a congenitally abnormal valve.

If in association with MVS, then it was due to rheumatic fever.

Normal valve area is 2.5-3.5cm2.
Significant AS is associated with valve area < 1cm2, and transvalvular pressure gradient > 50mmHg.

Question 12

Classic symptom triad with AS

Answer 12

Angina
DOE
Syncope

Question 13

General anesthetic goals for the pt with AS

Answer 13

Maintain NSR:
- Need time for atrial kick

Avoid bradycardia:
- BP is very dependent on HR. These pts have a very low SV, so a higher HR is needed to maintain a normal CO and BP.

Avoid sudden increases or decreases in SVR
Ensure adequate fluid volume for venous return and ventricular filling (frank starling mechanism!)

Question 14

Is RA or GA preferred in AS?

Answer 14

GA is preferred.

RA causes sympathectomy and drop in SVR

Question 15

Patho of aortic regurgitation

Answer 15

Acute:

• Infective endocarditis
• Trauma
• Dissection of thoracic aneurysm

Chronic:

• Rheumatic fever
• Chronic HTN

Question 16

Patho of Tricuspid Regurgitation

Answer 16

Usually due to pulmonary HTN.
RV becomes dilated. This dilation changes the normal anatomy and mechanics of the tricuspid valve.

These patients are usually functional, and as a whole, the disease is well tolerated.

Question 17

How do we treat a-fib with RVR?

Answer 17

BBs, CCBs, amiodarone, or digoxin.