all Flashcards
normal cardiac output
cardiac output is blood ejected from LV in 1 minute.
it is SVxHR. normal is 200ml/kg/min in neonate to 100ml/kg/min in adolescence
what 4 things affects SV
preload, afterload, contractility, compliance
cardiac index
CI = CO/BSA.
normal 3-4.2L/min/m2 regardless of body size.
what is EF
volume ejected vs volume remaining in LV
preload?
blood in ventricles at end of diastole and prior to contraction
determined by cardiac fiber length/stretch and volume returned from systemic and pulm circulation. most accurately determined by PAWP (cath lab or OR)
MAP
MAP=(COxSVR)+CVP
SNS stim releases what
norepi
parasympathethic stim releases what
acetylcholine with acts on right and left vagus nerve for relaxation of HR and conduction
alpha adrenergic receptors stim causes what
arterial vasoconstriction and increased intracellular calcium
stim of beta1 adrenergic receptors causes what
(dobutamine,norepi) increased SA node, increased inotropy, chronotropy, AV conduction
b2 adrenergic stim causes what
smooth muscle relaxation, bronchodilation
cardiac failure
failure of heart to maintain CO sufficient for body metabolic demands
left heart failure heart sound
s3 heart sound
pulmonary vascular resistance increases in response to?
decreased o2. so right heart failure can result from PHTN but also potentiates it because then u have less CO therefore less o2 resulting in more pulm vasoconstriction
cvp increased or decreased in right heart failure? what about pvr?
both increased
labs in heart failure
dilutional changes (anemia, hyponatremia, hypocalcemia, hypoglycemia), end organ dysfx: proteinuria, increased lactate, acidsosis, increased WBC, polycythemia, BNP levels
meds (for heart failure)
Improve contractility: b blockers, digoxin, dobutamine, dopamine, epi, vaso, calcium chloride, milrinone
Optimize preload: diuretics, sodium/fluid restriction
Decrease afterload: nitroprusside, ACE I, ARB, iNO
Anxiolytics, pain meds
dilated cardiomyopathy
most common type in kids.
aka congestive cardiomyopathy d/t s/s of CHF with decreased SV and EF.
hypertrophic cardiomyopathy
leads to left ventricular outflow track obstruction. things that increase HR/contractility can worsen.
thats why its most common cause of young sudden cardiac death in athletes.
restrictive cardiomyopathy
from fibrosis and scarring (defective endocardium). has minimal contraction so decreased diastolic function with normal systolic. poorest prognosis.
Dilated cardiomyopathy tx
vasoactives, inotropes, diuretics, afterload reduction, ACE-I (prils-angioedema) or angiotensin II receptor blockers (sartans)
whatdo calcium channel blockers do? and what condition are they good for
afterload reduction (HTN crisis), decrease contractility, improve LV function
myocarditis vs endo
myo usually virus. endo usually bacteria
pericarditis heart symptom
cardiac tamponade, rub.