Valves Flashcards
Aortic Stenosis - Valve size?
- Normal 3.0
- Severe less than 1.0
-or pressure gradient > 40
Aortic Stenosis on pressure volume
Up and to the right
Causes of aortic stenosis?
- Calcification of leaflets
- Rheumatic fever
- Endocarditis
Trio of symptoms for aortic stenosis?
SAD
1.Syncope - 3 year survival
2.Angina - 5 year
3.Dyspnea - 2 year
What disease is acquired with aortic stenosis?
Von Willebrand in 90% because molecule is damaged
Management of AS?
Full Slow and Constricted
-Increase preload
-Decrease HR
-Increase SVR
-Avoid regional
Art line waveform in AS?
Slow upstroke and delayed peak
Narrow pulse pressure with small amplitude
Mitral stenosis size?
Normal 5
Severe < 1
Transvalvular > 10
PA pressure > 50
Mitral stenosis most common in the world? US?
World - rheumatic fever
US - endocarditis
Lupus
What other disease can be seen in MS?
Afib due to increase in LA pressure
P/V loop of mitral stenosis?
Down and to the left
Management of MS?
HR - Slow
Preload - maintain
SVR-maintain
AVOID INCREASE IN PVR
Acute Aortic regurg P/V? Causes?
-low pressure and volume to the right
-usually caused by endocarditis or aortic root dissection
Chronic aortic regurg causes?
- Marfan , Ehler Danlos, ankylosing spondylitis
Aortic regurg management?
Full, Fast, Forward
Preload-maintain or increase
HR-increase
SVR - Decrease
Regional - okay
Aortic regurge A-line?
Double or biphasic peaks
Mital regurg causes?
-Ruptured tendineae
-Endocarditis
-Heart disease
-Carcinoid syndrome
P/V loop of mitral
regurg?
Volume gets sMaller - m for mitral
MV regurg management?
Full, fast, forward
HR-Increase
Preload- Increase
SVR - decrease
PVR - AVOID increase
Aortic stenosis murmur
- ASSS
Right of sternal border on systole
Aortic regurg murmur
-ARDS
Right of sternal border on diastole
Mitral stenosis murmur
MSDA
Left of apex on diastole
Mitral regurgitation murmur
MRSA
Left of apex of heart - systolic
What three things contribute to RMP?
- Chemical force
- Electrostatic counter force
- Sodium/Potassium pump
What three ways can HR be manipulated?
- Spontaneous rate of phase 4 increases
- Decreased threshold potential
- Increased RMP
DO2?
CO X (Hgb X SaO2 X 1.34) + (PaO2 x 0.003) x 10
Normal DO2?
1000 mL/ min
Normal O2 extraction?
25% or 250 mL
Normal CaO2?
20mL/dL
VO2 max?
250 mL /min ( how much O2 is used)
Calculate MAP
CO x SVR / 80
+CVP
How is blood viscosity calculated?
hematocrit and body temperature
Hypothermia and increased hematocrit have what effect on viscosity?
increased
When warming a patient off bypass, a lower Hct can help reduce sheering
Pressure inside ventricles and atriums?
LA - 5
LV - 25
RA - 10
RV- ? 120?
Thesbian veins?
drain into all chambers
also contributes to cardiac shunt
What are the three main cardiac veins? where do they drain?
- Greater vein - LAD - drains into coronary sinus
- Middle vein - PDA drains into RA
- Anterior vein - RCA drains into RA
Where do coronary arteries arise from?
Sinus of Valsalva
Coronary perfusion pressure?
LVEDP - Aortic diastolic pressure
What is the pathway for vasoconstriction of coronary arteries?
Alpha 1 and Histamine 1
Gq pathway
Increased phospholipase C increases IP3, Ca, DAG
What is the pathway for vasodilation of coronary arteries?
B2 - Gs > Increase cAMP > decrease in Ca
H2 - Gs > Increase cAMP > decrease in Ca
Muscarinic > increased NO
When are the Left coronary arteries perfused?
Diastole
When are the right coronary arteries perfused?
Throughout the cycle
When do most MI’s occur after surgery?
24-48 hours after with a 20% mortality
What factors decrease coronary flow?
Tachycardia
Decreased aortic pressure
Decreased vessel diameter
Increased end diastolic pressure
What does S3 heart sound mean?
heard after S2 during the beginning of diastole.
flaccid and inelastic heart
What does S4 heart sound mean?
Atrial kick
Heard before S1
Three conditions that can effect the pericardium?
Acute pericarditis-inflammation
Restrictive pericarditis - fibrosis
Cardiac tamponade
What is pulsus paradoxus?
impaired diastolic filing
decreased SPB >10 on inspiration
What is Kussmauls sign?
Increased JVD and CVP on inspiration
Anesthetic management of pericarditis
CO is HR dependent
Preserve HR and contractility
increased afterload
Pressure volume loop of cardiac tamponade?
Down and to left, decreased filling time as well
What is Becks triad?
Signs for cardiac tamponade
- Increased JVD
- Muffled heart tones
- Hypotension
Also have decreased ECG amplitude
Anesthetic treatment of cardiac tamponade
- Maintain spontaneous respirations
- Maintain or increase everything
Who does not need antibiotics undergoing cardiac surgery?
CABG
STENT
unoperated valves
GI/GU procedures without infection
What is the most common cause of cardiac death among athletes?
HOCUM
What is HOCUM?
Left outflow tract obstruction
caused by septum hypertrophy and SAM (systolic anterior motion)
Management of HOCUM?
Increase preload
Decrease HR
Decrease Contractility
Increase afterload
How to calculate MAP
Diastolic BP + 1/3 Pulse pressure
EF classification
> 50% normal
41-49% mild
26-40 moderate
<25 severe
Primary electrolyte of RMP?
Potassium
Does hypokalemia raise or lower RMP?
Makes it more negative
Primary electrolyte of TP?
calcium
Conditions that increase PVR?
Acidosis
Nitrous oxide
hypothermia
high peep
hypoxia
hypercarbia
Guidelines for waiting to have surgery after an MI?
-At least 4 weeks
-< 3 months have a 30% of recurrent
-3-6 months - 15
->6 months - 6%
Cardiac risked based procedures.
High risk? cardiac risk > 5%
-emergency surgery
-open aortic
-peripheral vascular surgery
-long procedures
how do PDEI work?
inhibit the breakdown of cGMP
HTN classification system?
Normal 120/80
Elevated 120-130 / 80
HTN 1 Sys >130-140 or Dia 80-90
HTN 2 Sys> 140 or Dia >90
HTN crisis Sys>180 and or Dia >120
What is more common primary or secondary HTN?
Primary. >95%
Secondary HTN causes?
Coarctation of the aorta -
1. upper limb BP > lower
2. Weak femoral pulse
3. Systolic bruit
Renvascular disease
1. Bruit
Cushings syndrome
Conn’s disease
Pheochromocytoma
Pregnancy - RUQ pain
When is the risk of re-stenosis greatest ?
30 days
Duration to wait for;
Angioplasty without stent?
Bare Metal?
Drug eluting?
CABG?
2-4 weeks
30 days
6 months for current otherwise 12 months
6 weeks
When should anticoagulant therapy be stopped?
Asipirn?
Clopidogrel?
Ticlopidine?
Don’t stop aspirin
7 days
14 days
Should heparin be used for patients with PCI?
no
What is the best treatment for thrombosis?
Stent with blood flow restored within 90 minutes
When does the patient experience the most awareness during bypass?
Sternotomy
What should ACT be for bypass?
> 400 seconds
Blood pressure goal for bypass cannulation ?
Sys 90-100 and or MAP <70
What is cardioplegia?
Potassium is given which increases the resting membrane potential which locks voltage gated Na+ channels shut
How is cardioplegia induced?
Potassium is given antegrade or retrograde.
if given antegrade, aortic valve must be competent and the aorta clamped
What blood pressure number do we relay on for organ perfusion?
MAP
How many units of protamine to reverse heparin on bypass?
1mg per 100 units of heparin
Classes of AAA
Crawford
Type 1 - descending plus upper abdominal
Type 2
- descending plus most of abdominal
Type 3 -lower descending plus most of abdominal
Type 4 - just abdominal
Classes of dissecting AAA
Standford
A - ascending
B- not ascending
Debakey
1- tear everywhere
2- tear only in ascending
3 - proximal descending
What AAA classifications are emergencies?
Anything of the ascending
Debakey 1 or 2 + Stanford A
Hardest AAA to repair?
Crawford type two because of renal arteries
What artery can is affected most by a AAA repair?
Artery of Adamkiewicz
What happens when an aortic cross clamp is applied? Hypervolemia or hypo?
Hyper by increasing venous return and reducing venous capacity
What happens to distal tissues when the aortic cross clamp is applied?
-Switches to anaerobic metabolism which increases to lactic acid and metabolic acidosis
-decreased temp
-Increased prostaglandins
What are the benefits to an EVAR?
shorter operative times
shorter length of stay
lower rate of transfusion
reduced morbidity
What is the artery of adamkiewicz?
Most important radicular artery that supplies the spinal cord
Thoracic 10
Perfuses anterior spinal cord
Strategies to protect the spinal cord?
Moderate hypothermia (31 degrees)
CSF drainage
Nerve monitoring
Avoid hypertension and hyperglycemia
Signs and symptoms of anterior spinal syndrome?
flaccid paralysis of lower extremities
Bowel and bladder dysfunction
loss of temp and sensation
**touch and proprioception are preserved
How is a AAA seen?
pulsatile abdominal mass
What size in cm requires repair of a AAA
> 5
Signs and symptoms of AAA rupture
back pain
hypotension
pulsatile mass
How is cerebral perfusion pressure calculated?
MAP-CVP
What is ACT kept above for a carotid ?
> 250
is an aortic cross clamp required during an EVAR?
no
what factors determine myocardial supply?
tachycardia - decrease supply
Increased preload - decrease supply
what factors determine myocardial demand?
preload
afterload
contractility
HR
how to calculate EF?
SV/EDV
or
EDV-ESV / EDV
How to calculate MAP?
1/3 sys + 2/3 dia
How can remodeling be reversed?
ACE Inhibitors
Aldactone
When is the sub endocardium and endocardium perfused?
Sub = diastole
Endocardium = systole
What percent of the CO goes to the coronary’s ?
5% or 250mL
At rest how much O2 is consumed by the heart? What’s the extraction of it?
8-10mL/min//100g
75%
What factors decrease coronary flow?
tachycardia
decreased aortic pressure
decreased vessel diameter
increased in end diastolic pressure
What factors decrease CaO2?
Anemia
Hypoxemia
What factors decrease O2 extraction?
acidosis
decreased capillary density
What factors increase O2 demand?
tachycardia
HTN
SNS stimulation
Increased wall tension
Increased afterload
Increased contractility
Increased end diastolic volume
NO pathway?
L arginine to NO
No goes to smooth muscle
NO activates guanylate cyclase
Guanylate cyclase to cGMP
cGMP reduces calcium
Phosphodiesterase deactivate cGMP
cardiac lab values and timeframes?
- CK-MB
-3-12 hours
-peaks in 24 hours
-returns in 2 days - Trop 1
-3-12hours
-24 hours to peak
-5 to 10 days - Trop T
-3-12 hours
-12 to 48 hours to peak
-5 to 14 days to return
What is S3 heart sound?
Early part of diastole - right after S2
-Signals CHF or volume overload
What is S4 heart sound?
Right before S1
-Signals non compliant ventricle
What is the treatment for an MI
Slower, smaller, and better perfused
Where do CCB bind to?
Alpha 1 subunit L type calcium
What CCB should be used to help with cerebral spasm?
Nimodipine
What patients do not need antibiotic prophylaxis against endocarditis?
CABG
unrepaired cardiac valve
Stent placement
