Cardiac Flashcards
Cardiac cycle
begins in Vent diastole (muscle relaxes) = 70% of blood flow
- remaining 30% left in atria is pumped into vents in atria systole (closure of AV valves)
- Pressure builds in vents then 55-70% ejected to pul and systemic systems
What makes S1
closure of AV valves; mitral and tricuspid
what makes S2
closure of semilunar (AV and PV) valves
Stroke volume
volume of blood ejected by each vent perisitnelty Approx 70 ml
EF
SV/EDV (amount of blood in the ventricles before systole) 55-70%
Cardiac Output
HR X SV
SV
Preload, afterload and contractility
Preload
Volume / stretch / loading the heart
Afterload
pressure / resistance
opens semi-lunar valves
Frank starling law
stretching cardiac muscle fibers during diastole will result in a stronger contraction
Causes of increased afterload
COPD, Systemic HTN, pul HTN, aortic valve stenosis
Decreased afterload causes
hypotension or vasodilation (shock)
Most immediate effect on afterload
HTN
Laplace’s Law
heart must work harder (increase tension or force) when the muscle is weak
Contractility
determined by calcium ion available and its interaction with actin and myosin. (inotropic state)
Causes of Decreased contractility
Acidosis, ischemia and cardiomyopathy
Heart failure
Less CO to meet body’s demands. dec contractility and SV and increased LVEDP and increased preload
Heart failure causes
Decreased contractility, SV, and increased LVEDF = heart dilation and increased preload
Major risk factor for developing HF
HTN
left Sided Heart Failure
HFrEF
Cause of HFrEF
HTN - inc afterload- inc preload (unable to eject normal amount of blood) -inc blood volume and pressure in pul veins - forced fluid out of vessels into tissues.
Unresolved Left HF causes
pressure/build up to right side of heart causing right sided heart failure
Right sided Heart failure
HFpEF
Patho of Right HF
inability of the right ventricle to provide adequate blood flow into pulmonary circulation. pul HTN, COPD, Left HF
high output (bi-V) failure
unresolved right heart failure results in left HF
Causes of High-out-put failure
severe anemia, nutritional deficiencies (berry-Berry), hyperthyroidism, sepsis (inc metabolic rate), extreme febrile states
Stages of heart failure
A : no symptoms /has risk factors
B: no symptoms/structure defects like MI
C: has symptoms (classifications come into play)
D: end stage / failure treatment needs pacer /transplant
Classifications of HF
Classified level of severity/damage
starts are stage C
Class 1 HF
Mild; no physical limitations.
Class 2 HF
mild; slight limitation to physical activity. comfortable at rest
Class 3 HF
moderate; marked decreased with physical activity. marked limited physical activity. Comfortable at rest
Class 4 HF
sever. cant complete physical activities without discomfort. no comfortable at rest.
Aortic Stenosis
Mid systolic cresendo decresendo murmur heard loudest at base
S 4 gallop present, fainting, sustained laterally placed apical pulse
Aortic stenosis
Aortic Regurgitation
early, high-pitched diastolic murmur heard at the left lower sternal border.
HTN, SOB that progressively worsens, cardiomegaly and pul edema on CXR
Aortic Regurgitation
Mitral stenosis
Rumbling, decrescendo (low pitched) diastolic murmur heard at apex of the heart
SOB with activity, pounding racing heart, JVD, Crackles,
Mitral stenosis
history of rheumatic heart disease associated with
Mitral stenosis
mitral regurgitation
blowing pansystolic/holosystolic murmur best at the heart’s apex
SOB, JVD, crackles in bases
Mital regurgitation
4+ pulses, HTN, pul edema and cardiomegaly
Aortic regurgitation
modifiable risk factor for Coronary Artery Disease (CAD)?
Obesity
Coronary artery disease (CAD) is mainly the result of
Longstanding atherosclerosis.
In CAD pumping ability of the heart can be impaired due to the deprivation of oxygen
Ture or false
True
major risk factor for the development of CAD is
Family history
Cor Pulmonale is
Right ventricular failure secondary to pulmonary hypertension
Most common cause of right heart failure is
Pulmonary HTN
In the healthy heart, the response to an increase in preload is for the stroke volume to
Increase
Hypertension has its most immediate effect on
Afterload
JVD, Hepatosplenomegaly, peripheral edema, cor polmonale, tricuspid valve damage
Right sided heart failure
Decreased EF, increased LV preload, pulmonary edema and dyspnea
Left sided heart failure
LVEDP
left vent end diastolic volume and if increased in HR = increased preload
