Witwer CV study guide Flashcards
Do the coronary arteries fill during systole or diastole?
Diastole
What determines the coronary dominance of a heart?
The posterior interventricular branch. If it arises from the left coronary artery the heart is left coronary dominant, if it arises from the right coronary artery, it is right coronary dominant.
Why can tachycardia cause myocardial ischemia? At what rate do we have concern?
If the heart is beating too fast, there is not enough time during diastole for the coronary arteries to get adequate blood supply. Rates above 180 decreases filling time
What is more common, right or left coronary dominance?
Right- 70%
Left -10-15%
Remainder of people are codominant
What are the branches of the left coronary artery?
Left anterior descending
Left circumflex
What are the branches of the right coronary artery?
Right marginal branch
Post Interventricular branch (most commonly)
What areas of the heart are supplied by the LAD?
Ant. left ventricle
Ant. 2/3 of interventricular septum (IVS)
Apex of heart
What areas of the heart are supplied by the left circumflex artery?
Lateral wall of left ventricle
What areas of the heart are supplied by the right coronary artery?
Posterobasal wall of left ventricle
Post. 1/3 of IVS (If right coronary dominant)
Right ventricle
AV and SA nodes
posteromedial papillary muscle in left ventricle
What is the most common place to have a coronary artery infarction?
Right coronary artery - 45%
4 types of ischemic heart disease?
Angina Pectoris
Chronic ischemic heart disease
sudden cardiac death
Acute myocardial infarction
Name some risks of ischemic heart disease
Male>female Advanced age Smoking HTN Lipid abnormalities DM
Underlying cause of majority of ischemic heart disease?
Hardening of the gruel (atherosclerosis)
Are patients with angina at risk for an AMI?
Yes, 10-20% of patients with angina have an AMI or unstable angina within 1 year of onset
Major difference between stable and unstable angina is ________.
A. Unstable is caused by an embolus
B. Unstable angina occurs at rest, while stable is relieved with rest
C. Stable angina occurs at rest, while unstable angina is relieved with rest
D. Unstable angina is less severe
B. Unstable angina occurs at rest, while stable angina is relieved with rest
What is the most common cause of stable angina?
Fixed atherosclerotic coronary vascular disease
What is a common EKG finding in angina?
ST depression. Depression indicates ischemia.
What is prinzmetal angina?
vasospastic angina. Caused by coronary artery vasospasms at rest, with or without ASCVD.
What is a foam cell?
Foam cells are macrophages that have migrated into the intima of an artery and taken in lipids.
What makes up a plaque?
Lipids from dead macrophages and cholesterol accumulates into a plaque
What is more common, essential or secondary hypertension?
Essential hypertension - makes up 85% of HTN
Two major determinants of systolic blood pressure
Stroke volume and compliance of the aorta
What determines the stroke volume?
Preload, afterload and contractility
Major determinant of diastolic blood pressure
Peripheral vascular resistance
Arterial smooth muscle contraction would increase or decrease diastolic BP?
Increase. Smooth muscle contraction increases peripheral vascular resistance
How does excess sodium effect BP?
It increases systolic and diastolic BP
By what mechanism does sodium increase systolic BP?
Increases plasma volume which increases stroke volume
By what mechanism does sodium increase diastolic BP?
Excess sodium produces vasoconstriction of peripheral arterioles, which increases peripheral vascular resistance.
T/F? Incidence of HTN is higher in Caucasians when compared to African Americans.
False. HTN is more common in African Americans
What is malignant hypertension?
Rapid increase in BP accompanied by renal failure and cerebral edema
What is concentric hypertrophy of the heart?
Reduction in the chamber dimension. Increase in wall thickness, capable of generating greater force.