Cardio (333E2) Flashcards
afterload
The pressure the ventricles must work against to pump blood out of the heart (opens semilunar valves) affected by vascular resistance, increases w/ vasocon, aortic stenosis & pulmonary htn
cardiac output (CO) equation
CO (ml/min) = stroke volume (systolic-diastolic) x heart rate (beats/min)
ejection fraction (%)
the % of blood pumped out of left ventricle with each contraction
hypertension
high blood pressure, pressure in arteries is higher than it should be (prolong changes make up & causes damage)
hypotension
SBP <90 mm/hg (do not only treat number bc some pt trend low)
infarction/necrosis
complete cut off of blood and oxygen to an area of the body
ischemia
blood flow (& oxygen) is restricted or reduced to an area in the body
myocardial contractility
how hard the heart contracts regardless of the stretch factor
orthostatic hypotension
upon standing, blood pressure drops (safety hazard, dizziness) blood pools, in healthy person no pooling
preload
The amount the ventricles stretch at the end of diastole (the amount of fluid in the ventricle) aka end diastolic volume -> increased preload increases SV which increases CO
pulmonary embolism
pulsus alternans
regular rhythm but strength of pulse varies with each beat (possible etiology = heart failure)
stroke
stroke volume
the amount of blood that is ejected from the left ventricle (into the body) every time it pumps in mL
venous thromboembolism
perfusion
passage of fluid through the circulatory system or lymphatic system to an organ or tissue (w/o this, tissues die bc O2 cannot get where it is needed)
if low perfusion to the brain, what are some symptoms
dizziness, might pass out, confused
if low perfusion to the toes, what are some symptoms
pale, weak pulses, sluggish cap refill
cardiac output
volume of blood pumped by the heart in one minute
what is the indirect measure of cardiac output
blood pressure (& heart rate)
what might alter cardiac output
-change in heart rate (in or de)
-decrease of stroke volume
-myocardial contractility
ex: meds, disease processes, activity
if stroke volume lowers, what will heart rate do in attempt to maintain cardiac output
heart rate will increase (a compensatory mechanism)
classifications of ejection fraction
-normal: 50-70%% [comfy during activity]
-borderline: 41-49% [pos symp during activity]
-heart failure: <40% [pos symp at rest]
what is the power house chamber of the heart
the left ventricle