Anesthesia for Valvular Heart Disease - Quiz 5 Flashcards
What causes Aortic Stenosis?
Calcification & Fibrosis of a Normal Aortic Valve or a Congenital Bicuspid Aortic Valve
&
Rheumatic Disease
What is the Normal Aortic Valve Area?
2 - 4 cm2
At what Aortic Valve Area would indicate surgical intervention?
< 1 cm2
(Severe Aortic Stenosis)
What is the Mean Pressure Gradient for a Normal Left Ventricle?
> 50 mmHg
Poor LV Function = Low Mean Pressure Gradient
What happens to the Left Ventricle w/ Aortic Stenosis?
Concentric LV Hypertrophy to ↓Wall Stress
↓Diastolic Compliance & Coronary Blood Flow
O2 Supply/Demand Mismatch
↑LVEDP & LVEDV
Myocardial Ischemia
What are the Hemodynamic Goals for Aortic Stenosis?
Maintain Preload, Contractility, and NSR for Atrial Kick
Maintain CPP w/ Neosynephrine or Norepi
Avoid Myocardial Depressants & Hypotension
What type of Anesthesia is Contraindicated for a pt w/ Severe Aortic Stenosis?
Spinal & Epidural
Poorly tolerated if pt has ↓Preload or ↑HR
In addition to standard monitoring, what else should be included for pts w/ Severe Aortic Stenosis?
A-Line
CVP
PAC
TEE
What is a problem that occurs for a pt w/ aortic stenosis when Weaning from Bypass?
Stiff Stone Heart w/ subaortic or cavitary obstruction
How should stone heart be treated?
- Volume
- Inotropes (can worsen obstruction)
- B-Blockers
- Myomectomy (Rare)
What causes Aortic Regurgitation?
Aortic Root Dilation
Abnormal Cusps
Cusp Prolapse
What are causes of Aortic Root Dilation?
HTN
Ascending Aorta Dissection
Cystic Medial Necrosis
Marfans
Syphilitic Aortitis
Ankylosing Spondylitis
Osteogenesis Imperfecta
What happens to the LV with Chronic Aortic Regurgitation?
LV Volume & Pressure Overload
Eccentric Hypertrophy - thins out & dilates to ↑compliance
↑LVEDP & LVEDV
CHF, Arrythmias, Death
What are the Hemodynamic Goals for Aortic Regurgitation?
Avoid Bradycardia & High Afterload
HR = 90
What meds are used for Aortic Regurgitation?
Nitroprusside
Epinephrine
Milrinone
Why are Intra-Aortic Balloon Pumps contraindicated for Aortic Regurgitation?
IABP will increase Regurgitant Volume
What causes Mitral Stenosis?
Rheumatic Disease
Fusion of MV Leaflets
Comissures
Calcifications & Thickening of MV
When is surgery indicated for a pt w/ Mitral Stenosis?
MVA < 1 cm2
&
Presence of LA Clot
What problems are associated w/ Mitral Stenosis?
Inadequate LV Filling
Pulm. HTN
Atrial Arrythmias
RV Dysfunction
What are the Hemodynamic Goals w/ Mitral Stenosis?
Maintain NSR
Avoid Tachycardia
Avoid Worsening Pulm. HTN
What are factors that worsen Pulm. HTN?
Hypercarbia
Acidosis
Hypothermia
Sympathetic Activation
Hypoxia
Which med is the most useful drug in managing pts w/ severe Mitral Stenosis?
Esmolol - fast on and fast off
10-20 mg bolus
50-100 mcg/kg/min
Which med should be avoided in pts w/ Mitral Stenosis?
N2O - worsens Pulm HTN
What causes Mitral Regurgitation?
- Myxomatous Degeneration - most common
- CAD/Ischemia - Papillary & LV Dysfunction, Annular Dilation, Tethering
- Endocarditis
- Trauma
What are the Hemodynamic Goals w/ Mitral Regurgitation?
Fast Full Foward
High/Normal HR
Maintain Contractility
↓Afterload (NTG, SNP)
In Mitral Regurgitation, will the LV ejection fraction increase or decrease after Mitral Valve Repair?
EF will Decrease - LV no longer has two outlets (LA & Aorta)
What causes Triscuspid Regurgitation?
Rheumatic Disease
Endocarditis
Ebstein’s
Trauma
RV Dilation
What is the Pathophysiology of Tricuspid Regurgitation?
Dilated RA
RV Overload
Pulm. HTN
Right Heart Failure
Hepatomegaly & Ascites
What are the Hemodynamic Goals w/ Tricuspid Regurgitation?
Avoid Pulm. HTN & PVR
Normal/High Preload
Avoid Hypotension w/ Inotropes & Volume
