Coronary & Pulmonary Circulation Flashcards
(19 cards)
where do most transmural MIs occur?
anterior LV or inferior LV
which leads to use to look for MI in anterior LV?
precordial Leads, I, aVL
which leads to use to look for MI in inferior LV?
leads II, III, aVF
The heart is perfused primarily during what phase of the cardiac cycle?
ventricular diastole
being able to maintain a flatline of blood flow over a range of pressure
autoregulation
flow = ?
flow = change in pressure / Resistance
myogenic mechanism: For constant flow to be maintained, _________in ΔP must be met by _________ in R
myogenic mechanism: For constant flow to be maintained, an increase in ΔP must be met by an increase in R
how is the myogenic mechanism accomplished?
through stretch-activated channels to increase vascular contraction.
what is the coronary reserve related to?
how well the arteries can vasodilate
you would expect a ______in coronary reserve in heart failure
reduction (lessened ability to produce NO to induce vasodilation)
increased metabolism–>incr hypoxia–>incr ATP turnover results in what?
incr cellular adenosine accumulation–>activates vasodilation
what are the 2 phases of sympathetic regulation of coronary circulation?
phase 1: vasoconstriction via NE
phase 2: metabolic vasodilation, incr force of contraction
pulmonary vs coronary anatomy: pulmonary have _____vessels, _____internal diameter lumens, ______ vascular smotth muscle, _____resistance
pulmonary have thinner vessels, greater internal diameter lumens, less vascular smotth muscle, lower resistance
does zone 1 or 3 have a higher perfusion pressure?
zone 3 (gravity!)
what mediates vasodilation in response to hypoxia in coronary vasculature?
adenosine
in pulmonary circulation, hypoxia mediates what effect?
vasoconstriction
opening of previously clsoed capillaries
recruitment (mechanism of passive regualtion)
accomodation of incr blood volume
distension (mechanism of passive regualtion)
chronic hypoxemia can result in _____ ventricular failure
right
