Hemodynamics #3 Flashcards
Law of LaPlace
Tension is directly related to diameter, inversely related to the thickness of the container.
Increased tension: increased O2 demand
Decreased tension: decreased O2 demand
**primary determinant of O2 consumption, followed by contractility.
Dilated Cardiomyopathy
- Systolic failure: fails to clear or evacuate ventricles. No issues w/ diastolic filling.
- Heart is stretched, muscle tissue thin, increased tension.
- Law of LaPlace
- secondary or volume overload (not pressure)
- CHF, status post AMI
Treatment for dilated cardiomyopathies
Cardiac glycosides*, inotropes (dopamine / dobutamine**) & diuretics
- Digitalis
- decrease in after load w/ vasodilation desired.
Digitalis mechanism
- poisons Na/K pump
- heart retains Na
- Antiporter channel forced to secrete Na out
- as Na is forced out, Ca is introduced
- Ca enhances work ability of cardiac cells
Hypertrophic Cardiomyopathy
- Diastolic Failure
- muscle has become thick and large
- muscle built on inside, not outside
- decreased intraventricular space
- great squeeze, limited diastolic filling.
- preload becomes critical
- secondary to pressure overload (HTN) not volume.
Hypertrophic Cardiomyopathy Tx
- Fluid to increase preload
- Increase diastolic filling time
- beta blockers (decrease HR=longer ventricular fill time.
- Ca Channel blockers
- Amiodarone (primarily blocks K)
IHSS define and how to recognize
Idiopathic Hypertrophic Subaortic Stenosis
- Hypertrophic Cardiomyopathy
- Systolic murmur at level w aortic valve (2nd intercostal space, R border of manubrium)
Restrictive Cardiomyopathy
- Systolic failure
- heart looks relatively normal
- muscle thickened, fibrotic, stiff
- hypodynamic heart, hypoplastic
- Trasmural ischemic tissue fibrosis
- no movement or ejection
Restrictive Cardiomyopathy Treatment
Diuretics, anti-coagulation*, and cardiac glycosides**.
- Fluid resuscitate with caution, as fluid cannot be cleared.
- stagnant blood flow increases clot formation.
- *supercharges muscle that is functioning
Primary vs secondary hypertrophic disease
Primary: heart was first problem, desease characteristics are secondary to heart
-AMI, pulmonary edema
Secondary: heart disease is secondary to another problem
-HTN
Multi valvular disease suggests what illness was suffered?
Rheumatic fever
- Autoimmune disorder triggered by strep a
- bulbous lesions develop on leaflet cusp edges
- scarring and fusion develop
- stenosis and regurgitation follow
Where do you hear the aortic heart tone?
2nd intercostal space, just R of Sternum
Where do you hear the pulmonic heart tone?
2nd intercostal space, just L of Sternum
Where do you hear the tricuspid heart tone?
4th intercostal space, just L of sternum
Where do you hear the mitral heart tone?
5th intercostal space, mid-clavicular line
Apex or heart
Point of maximal impulse
