Introduction to Cardiovascular Medicine Flashcards
(32 cards)
3 major coronary arteries and what they supply
LAD- anterior left ventricle and anterior 2/3 septum
Left circumflex- lateral wall of LV
Right Coronary Artery- Right ventricle, inferior LV, posterior 1/3 septum
left coronary arteries are a branch of what?
left main coronary artery
blood supply of conduction system?
Sinus node- right coronary artery or left circumflex
AV node- posterior descending artery
Hi-purkinje- anterior 2/3 done by LAD, posterior 1/3 by PDA
vagal efferents to heart
distributed to sinus and AV nodes
primarily cause decrease in HR
sympathetic efferents to heart
wide distribution
increase HR, conduction velocity, contractility
cause vasoconstriction via a-adrenergics
p cells
sinus and av node cells
simple structure, few sarcomeres, undifferentiated junctions
difference in APs in between nodes and muscles?
refer to notes
diagram the ionic flow in the muscle during contraction and relaxtion
refer to notes
diagram Ca’s interaction with troponin and how it results in muscle contraction
refer to notes
carotid sinus massage
manual carotid body massage which induces parasympathetic surge
describe the baroreflex system in the cardiovascular system
stretch in carotid or aortic sinus
afferent fibers (hering/glossopharyngeal or vagal respectively)
nucleus tractus solitarius
preloads effect on tension generation. how does inotropy affec this?
greater preload = greater stretch in muscle fibers = greater sarcomere overlap = greater ability to generate tension = greater CO
increased ionotropy will increase CO at a given heart size
inotropy
the force and velocity of myocardial contraction independent of initial length
related to rate and amount of intracellular Ca influx
more Ca = greater myosin and actin interaction = more force
afterload. how is it related to blood pressure?
tension developed by a muscle after it starts to contract
related by law of laplace
T = P x r / (2wall thickness)
easiest way to decrease afterload. how can this be calculated
decrease system vascular resistance
SVR = BP- CVP/ CO
phases of diastole
begins before LV ejection is complete- triggered by reuptake of Ca- “lusitropy”
isovolumic relaxation- no valves open. ends when LV P falls below LA
Rapid filling- most LV filling occurs right after mitral valve opens. determined by LA pressure, LV compliance, LV elastic recoil
diastasis- little volume change occurs
atrial kick- LA contraction
draw the cardiac cycle
refer to notes
ejection fraction
SV/EDV
determinants of LV systolic fxn
preload, contractility, peripheral vascular tone
determinants of LV diastolic fxn
lusitropy, LA pressure, LV compliance, HR, atrial contraction
draw 3 different LV function curves
refer to notes
swan ganz catheter
balloon inflated in pulmonary tree and finds pulmonary wedge pressure, roughly equivalent to LV diastolic pressure or LA pressure
normal is 0-12
what can be see on chest xray
cardiac enlargement- heart failure
increased pulmonary venous pressure- redistribution of blood to upper lung fields and pulmonary edema as fluffy infiltrates
echocardiogram and terms
ultrasound of heart
hypokinesis- less movement than expected
akinesis- no movement
dyskinesis- segments move in opposite direction than expecgted
