Flashcards in Ischemic Heart Dz Deck (33):
the 3 main determinents of MVO2 (myocardial oxygen consumption)
3. heart rate
*note: NOT preload!! it's a very minor contributor
MVO2 double product estimation equation:
when does this underestimate?
HR * sysBP
underestimates in any outflow obstruction e.g. aortic stenosis or HOCM
what are the 2 major determinants (in order) of coronary perfusion pressure? explain.
1. Aortic Pressure - determines if coronary ostia are occluded or not for blood to flow through them to coronaries.
2. early diastole is when coronary blood flow is highest so longer diastole -> more blood. which is why SNS overactivity/tachycardia reduces CBF
Coronary Blood flow equation (Q=)
Q = (Aortic pressure - RAP)/ coronary resistance
Q = (P-RAP) / R
so if high rap, low Q. this happens in tricuspid stenosis or other causes of obstructed flow from RA to RV
what drugs can you give to someone who has had myocardial stunning to help reverse and restore myocardial function?
beta agonists: milrinone, digoxin
which cells mediate thinning of fibrous cap?
Th1 T cells -> attract macrophages -> macrophages decrease amt of collagen
in MI complications, what 2 specific findings will you have in ventricular septal rupture?
1. step-up oxygenation between right atrium and right ventricle
2. new holosystolic murmur
2 specific findings in papillary muscle rupture?
1. acute mitral regurg -> new systolic murmur
2. giant v waves
does ventricular septal rupture more commonly in anterior STEMI or inferior STEMI?
papillary muscle rupture occurs more often after inferior MI or superior MI?
INFERIOR MI. both get blood from RCA. also its usually the posteromedial papillary muscle that ruptures, not anterolateral. posterior makes sense.
signs/symptoms of LV free wall rupture (complication of MI)?
vomiting, pleuritic chest pain, agitation, jugular venous distention, paradoxic pulse, supine hypotension, cardiac tamponade with equalization of heart chamber pressures
lateral free wall rupture of LV is most commonly caused by which artery?
left circumflex coronary artery thrombosis
findings in LV aneurysm:
dyskinetic apical impulse + S3 plus or minus systolic murmur
findings in autoimmune pericarditis aka Dressler syndrome:
sharp precordial chest pain when lying down. relieved by sitting up and leaning forward. pain may radiate to left trapezius.
pericardial friction rub
ECG: ST elevated
most common cause of variant angina?
epicardial coronary artery spasm superimposed on atherosclerosis of that artery
unique symptom of variant angina?
chest pain at REST AND NIGHT (wakens patient)
what does ECG of stable angina episode look like?
same as NSTEMI. ST depression + T wave inversion
what does ECG of variant angina episode look like?
ST segment elevation. like STEMI b/c both transmural
what ECG finding is DIAGNOSTIC of STEMI?
when does it appear?
Q waves, same day as MI
what characteristic findings in VSR?
new holosystolic murmur, step up in oxygenation from RA to RV
does pulmonary edema develop in ventricular septal rupture?
why yes it does
what new findings do you get with mitral papillary muscle rupture?
new systolic murmur. can be early, holo, or late
giant v waves
where does pain from autoimmune pericarditis/Dressler syndrome radiate to?
trapezius. if it does radiate. also the chest pain is worse laying down and better up and leaning forward
pericardial friction rub and resting ECG shows ST elevation in multiple leads? diagnosis??
autoimmune pericarditis/Dressler syndrome
hypo ______ and hypo______ prolong QT interval and predispose to Torsades de Pointes
4 medications that prolong QT interval
ECG findings of wolff-parkinson-white syndrome?
plus or minus wide QRS...or narrow?
which 3 medications can cause AV block?
beta blockers, verapamil, digoxin
6 things that downregulate JG cells:
1. increased NaCl
2. increased renal perfusion
3. increased Calcium
4. adenosine (increases calcium)
5. decreased cAMP
6. hyperkalemia (increases calcium)
6 things that upregulate JG cells:
1. increased cAMP
2. prostaglandins PGE2 (increases cAMP)
3. decreased calcium
4. decreased renal perfusion
5. decreased NaCl
6. hypokalemia (decreases calcium)
what is the triad in Conn syndrome and what is it a mainfestation of?
2. hypokalemia (may have periodic hypokalemic paralysis)
3. metabolic alkalosis
and obviously high aldosterone
drugs of choice for treating AVNRT?
adenosine and calcium channel blockers