normal cardiac anatomy, physiology, and function Flashcards
Describe the blood supply from the LAD
comes from the left main coronary artery
branches to septal branch, which supplies the anterior 2/3 of interventricular septum
LAD also suppoies the anterior wall of left ventricle
LAD most common site of coronary occlusion
Describe the blood supply from the circumflex artery
comes off the left main coronary artery
supplies the left atrium, the lateral wall of the left ventricle, and the posterior wall of the left ventricle
-10% of patients’ posterior descending branch comes of f the circumflex
what important arteries come off the right coronary artery?
posterior descending brance (in 70% of pts- 10 % of pts have the posterior descending branch that arises from the circumflex)
marginal branch
SA, AV nodal branches
posterior descending artery
supplies the inferior wall of the left ventricle, the posterior 1/3 of the the interventricular septum
what is supplied by the marginal branch?
right atrium and ventricle
what events increase stroke volume?
catecholamine release, increased intracellular calcium, lowered extracellular sodium, digoxin use, anxiety, exercise
what events decrease stroke volume?
beta blockers, heart failure, acidosis, hypoxia
What is the formula for calculating mean arterial pressure?
diastolic arterial pressure + 1/3 pulse pressure, where pulse pressure is the systolic arterial pressure minus the diastolic arterial pressure
another way of writing this:
2/3 diastolic pressure + 1/3 systolic pressure
What method should be used to read an EKG?
-determine rate
-determine rhythm (regular/irregular; sinus vs not)
-look at intervals- PR should be less than 0.2 s; qrs less than 0.12; look at qt
-look at axis
-look at p wave shape- normal or not?
look at qrs shape- wise? hypertrophied?
-ST segment and T-wave- normal ,depressed, elevated, inverted?
