The flashcards below were created by user
Shells33
on FreezingBlue Flashcards.
-
Increasing age, Male gender, Genetic predisposition/family history are all what types of risk factors for IHD?
non-modifiable
-
Cigarette smoking, hypertension, obesity, and sedentary lifestyle are all what types of risk factors for IHD?
modifiable
-
How does hypertension increase the risk of IHD?
direct vascular injury, left ventricular hypertrophy, and increased myocardial oxygen demand
-
hypercholesterolemia, hyperglycemia, low hdl levels are what type of risk factor for IHD?
Partially modifiable
-
What all does the Right coronary artery perfuse?
- 1) Right Atrium
- 2) Right Ventricle
- 3) LV inferior Wall
- 4) IF right dominant: PDA --> posterior LV & superior/posterior IV septum and inferior wall
-
What all does the Left coronary artery perfuse?
- 1) Left Atrium
- 2) IV Septum
- 3) Left Ventricle (septum, anterior, lateral wall)
-
What does the LAD perfuse?
septum and anterior wall of LV
-
What does the circumflex artery perfuse?
lateral wall of LV
-
If the patient has left dominant circulation, what does the circumflex artery perfuse?
posterior septum and inferior wall of LV
-
What perfuses the SA node?
-
What perfuses the AV node?
- RCA (90%)
- Circumflex (10%)
-
What perfuses the bundle of His?
LAD and PDA
-
The anterior papillary muscle of the mitral valve is perfused by?
LAD and Circumflex
-
The posterior papillary muscle of the mitral valve is perfused by...? What indication does this have?
PDA only - more vulnerable to ischemic dysfunction
-
How much is normal resting coronary blood flow?
225-250 ml/min
-
Does the heart get any blood directly from the chambers of the heart?
yes - from the inner 0.1 mm of endocardial surface but it is an insignificant amount
-
Where does the hearts most significant source of blood supply come from?
epicardial vessels - outer surface vessels that supply most of the muscle
-
What is the significance of HR on coronary perfusion?
increased HR = less diastolic time = less perfusion time
-
Why doesn't the heart receive blood during systole?
The contraction of the LV raises the intramyocardial pressures to equal systemic pressure --> almost total occlusion of the intramyocardial part of the coronary arteries
-
How do you determine coronary perfusion pressure?
CPP = ADP - LVEDP
-
Does the RV receive perfusion during systole?
yes
-
What are 4 things that control coronary blood flow?
- 1) heart rate (time spent in diastole)
- 2) CPP = ADP - LVEDP
- 3) CaO2 (SaO2 x Hgb)
- 4) Coronary Vessel diamter (Poiselle's flow, radius)
-
How do you determine the delivery of oxygen to an organ? (DO2)
DO2 = CaO2 x CO
CaO2 = (SaO2 x 1.39 x Hgb) + (0.0031 x PaO2)
-
Which is more important when determining myocardial blood flow: MAP or ADP?
ADP
-
Why is it bad to be hypotensive with a PCWP of 40?
You've narrowed the gradient between ADP and LVEDP = decreased CPP
-
What is the SvO2 in the coronary sinus?
30%
-
If myocardial oxygen demand increases, what must happen? How is this different form other tissues?
coronary blood flow must increase. Other tissues can simply extract more oxygen from Hgb.
-
How does the heart increase coronary blood flow?
- It releases vasodilating substances:
- - Adenosine (ATP degradation)
- - K ions
- - H ions
- - CO2
- - Bradykinin
- - Prostaglandins
- - Nitric Oxide
-
Alpha 1 receptors are located _______ and cause ______
epicardial vessels - stimulation causes vasoconstriction (excessive stimulation can proceed ischemia and angina)
-
Beta 1 receptors cause ____ and _____
Increased HR and increased contractility
-
Beta 2 receptors are located mainly in ____ and _____ and cause _____
intramuscular and subendocardial vessels...causes vasodilation
-
Where does the myocardium get most of its energy?
breakdown of fatty acids
-
What are the 3 venous drainage systems of the heart? Which one is different, how?
- 1) Coronary Sinus
- 2) Anterior Cardiac Veins
- 3) Thebesian veins
Thebesian veins dump into all chambers (including LV) which means a portion of outflow blood is deoxygenated
-
What is angina pectoris thought to be caused by?
glycolosis --> lactic acid
-
Which two coronary arteries have the highest mortality when occluded?
-
What is a nuclear stress imaging?
Pharmacologically induced stress (dobutamine, adenosine, dypyridamole) followed by imaging to assess wall motion and/or tracer (thallium, technetium) uptake to assess perfusion
-
What is the gold standard for determining the condition of coronary arteries?
Cardiac Cath
-
The fundamental purpose of beta blockers is to....
decrease oxygen demand
-
Why might Ca Channel blockers be risky?
decrease BP and contractility --> narrowing of gradient between ADP and LVEDP --> decreased CPP --> further infarction
-
Ace inhibitors have replaced which drug?
digitalis
-
What are the 4 causes of death after an MI?
- 1) pump failure
- 2) pulmonary edema
- 3) V fib
- 4) ventricular rupture
-
What does it mean when a portion of muscle becomes dyskinetic?
it bulges out - the volume of blood in the bulge reduces CO
-
What contributes to post MI pulmonary edema?
weak pump and decreased renal perfusion --> increased blood volume
-
How does ischemia affect the repolarization of myocardial muscle?
It often cannot completely repolarize --> irritability --> Vfib
-
What 4 things increase the risk of Vfib post MI?
- 1) depletion of K --> increased extracellular K
- 2) Injury current
- 3) Increased sympathetic response
- 4) LV dilation
|
|