EXAM 2 - Cardiomyopathy, Mediastinoscopy, CV Pharmacolgy Flashcards
All forms of cardiomyopathy can result in
CHF and death
decreased contractile state of the heart muscle that cannot be attributed to a specific external causative factor.
this refers to what pathologic cause?
intrinsic
intrinsic to the heart
factors that can cause extrinsic cardiomyopathy - ischemia, chronic inflammation, CHD, metabolic diseases (hemochromatosis) and toxins (ETOH, chemo, etc.).
this refers to what pathologic cause?
Extrinsic
-effect the heart
Name the 4 types of cardiomyopathies:
- hypertrophic
- dilated
- restrictive
- arrhythmogenic right ventricular CM
genetically transmitted cardiomyopathy
hypertrophic CM
most common cause of sudden death in pediatric and young adult populations
hypertrophic cardiomyopathies
an obstructive Hypertrophic CM is called:
idiopathic hypertrophic subaortic stenosis (IHSS)
Name the 4 major cardiac changes in HCM:
- ventricular hypertrophy
- decreased ventricular chamber size
- increased ventricular wall thickness
- impaired ventricular relaxation
the myocardial defect associated with HCM is:
CONTRACTILE mechanism
asymmetric hypertrophy of interventricular septum of LV causes a
left outflow tract obstruction
and hemodynamic consequences are similar to those of aortic stenosis
due to the presence of collagen, these are narrowed in HCM:
coronary artery walls
rapid acceleration of blood traveling through narrowed outflow tracts creates a
venturi effect
which pulls the anterior MV into the outflow tract. the MV leaflet further obstructs the LV outflow compromising outflow via regurg too.
* Bernoulli’s law
is HCM systolic or diastolic dysfunction?
BOTH
-Increase LVEDP in presence of low/normal EDV
loss of lv compliance requires a greater contribution of volume from…
atrial contraction
b/c 75% of LV preload comes from the LA in HCM, what is critical for adequate SV?
NSR
increased LVEDP decreases CPP to the Hypertrophic LV…
so in the HCM, increased myocardial O2D, thickening of CA’s decreasing perfusion all lead to:
ischemia
-only takes a little bit of stress to cause ischemia in these pts. (think about intubation)
HCM S/S:
DOE
angina pectoris - relieved by lying down (decrease LV outflow tract obstruction
SVT/Ventricular arrhytnmias
systolic murmur (S3 and S4? S4 gallop yes -but not sure about S3?)
HCM anesthetic mgmt focus on strategies that alleviate and do not increase
LV outflow obstruction!
- adequate or slightly elevated LV vol
- avoid decreased venous return or interference with Preload; and factors that decrease contractility (b/c this empties the ventricle vol more)
what should be treated IMMEDIATELY in HCM?
this also impacts anesthetic plans - we should not do what?
hypotension
-M&M says no spinal/epidural b/c they decrease preload/afterload increasing Obstruction
Goals for HCM:
HR:
Preload:
Afterload:
Contractility:
HR: NSR/ maintain
Preload: FULL - volume FIRST!
Afterload: Maintain or Increase (pure vasoconstrictor is SECOND line of defense for hyoptenstion)
Contractility: decrease (increased would lead to collapse by increasing obstruction)
HCM obstruction will be worsened by:
- increased contractility (dig, catecholamines)
- decreased PL (hypovolemia, vasodilators, tachy, PEEP)
- Decreased AL (hypotension, vasodilation)
*nitrates, dig, diuretiics worsen LV obstruction
HCM obstruction will be decreased/improved by:
- decreased contractiliy (Beta blockers, volatile anesthetics, CCB to counteract sympathetic activation if/when occurs)
- Increased PL (Hypervolemia, bradycardia)
- Increased AL (hypertension, alpha adrenergic stimulation)
First and second line of defense for hypotension in Hypertrophic CM:
1 - FLUID!!
2. Pure vasoconstrictor (Neo)
Dilated cardiomyopathy (DCM) is the most common form and most often occurs in:
adults
DCM may develop in what type of pts:
- genetic predisposition (duchenne muscular dystrophy)
- viral inflammation from metabolic abnormalities
- autoimmune mechanisms
- toxins
- Men > Women
- women during pregnancy
DCM is eccentric or concentric?
eccentric
- overall size and vol are enlarged d/t volume overload
- sarcomeres lengthen or increase in number (rather than thicken in concentric)
eccentric hypertrophy results in compliance problems leading to diastolic dysfunction - hypertrophy affects which ventricles?
BOTH Left and Right ventricles
LV chambers increase in size w/o associated increase in diameter of the V-walls or interventricular septum. This decreased SV due to decreased contractility leads to diastolic dysfunction.
What law is this an example of?
law of laplace