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
Systolic murmur
Lub murmur dub… Lub murmur dub
Diastolic murmur
Lubb dub murmur… Lubb dub murmur
Aortic stenosis
Aortic valve won’t open
Aortic valve is open during systole
-systolic murmur
Aortic regurgitation
Aortic valve incompetent
- aortic valve closes during diastole to prevent blood from backing up into heart.
- diastolic murmur
- back pressure into the LV, LA, lungs… Pulmonary congestion, heart overloaded, stretching of heart muscles.
Mitral stenosis
Mitral valve won’t open smoothly
- mitral valve opens during diastole to allow the ventricles to fill
- diastolic murmur
Mitral regurgitation
- mitral valve is incompetent and leaks
- mitral valve closes during Systole to prevent blood from entering LA during LV contraction.
- systolic murmur
- blood will back in to the LA, lungs resulting in pulmonary congestion
Pulmonary stenosis
Pulmonary valve won’t open smoothly
- pulmonary valve is open during systole to allow blood into the lungs
- systolic murmur
VSD murmur
Ventriculoseptal defect
- hole between R and L ventricles
- L to R shunt
- overloads the lungs
- predominately systolic murmur
- loud murmur equals small defect
- silent murmur equals large defect
- auscultated primarily over apex of heart
RN/WT murmur
- Auscultated over all valvular areas
- biphasic murmur (lub murmur dub murmur)
- predominantly found in south eastern Caucasian population
- depressed socioeconomical status frequently living in mobile homes
