Tools of Trade Flashcards
(42 cards)
Mechanism behind CXR
1) Tissue decr radiation penetration
2) Tissue = white
air = black
what is white on CXR
what is black on CXR
white = tissue black = air
Mechanism of echo
1) US sent to body and return to transducer
Returned ultrasound forms:
M mode
moving location of transducer at varying angles to capture image
Returned ultrasound forms:
color doppler map of blood flow
blue = flow away
red = flow toward
Mechanism of micro-bubbles
1) micro bubbles <10um pass thru pulm capillaries
2) creates micro-bubbles ~16 um
Where can micro-bubbles not pass thru?
1) can’t pass thru pulm capill b/c too big
2) not in left heart unless you have R–> L communication + flow
Examples of when agitated saline and micro bubbles can appear in left heart
1) intra cardiac shunt
2) intra pulm shunt
when do you see bidirectional flow (bidirectional intra-cardiac shunt)
atrial septal defect
Diseases you can tell from echo
1) shunts
2) murmurs
3) intracardiac masses
4) bacterial endocarditis
5) pericardial disease/fluid
Examples of CAD
1) asymptomatic/non-obstructive CAD
2) ischemia
- stable, exertional angina
- unstable angina
3) MI, cellular necrosis
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Mechanism behind stress testing
1) precipitate ischemia by incr myocardial O2 demand (stress)
How do you identify ischemia from stress testing?
find ischemia by changes in
1) BP
2) ECG
3) sx
4) perfusion (flow) imaging
5) echo (wall motion) imaging
types of stress tests
1) exercise treadmill
2) imaging stres
- echo
- radionuclide (nuclear)
indications for exercise treadmill test
1) CAD screening
2) chest pain
3) exercise capacity
4) prognosis (exercise duration best)
5) evaluate after revasc
Contraindications for exercise treadmill test
1) unstable angina
2) life threatening arrhythmias
3) uncompensated HF
4) advanced AV block
5) acute myocarditis/pericarditis
6) critical aortic stenosis
7) significant HOCM
8) uncontrolled HTN
what is exercise treadmill stress test best designed for
good at Identifying left main or 3 vessel CAD
sensitivity decr with 1 vessel CAD
possible results from exercise treadmill stress test
1) HR response
2) BP response (systolic incr >20)
3) duration
4) ecg
5) sx
pharmacologic agents for imaging stress test
vasodilator- HR independent bc HR not increasing
1) dipyridamole
2) adenosine
3) regadenosen
dobutamine- make heart exercise w/o pt exercising
indications for imaging stress test
1) abnormal baseline ECG, WPW
2) incr sensitivity
3) localization
4) preop cardiac risk assessment
5) myocardial viability
contraindications for imaging stress test
same as exercise stress test
important patient prep for imaging stress test
1) no significant RAD –> bronchospasm with drug
(regadenoson most specificity for pulm so least side effect)
2) no caffeine/theophylline –> counteracts effect of adenosine
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