S7C55 - Low probability ACS

Question 1

A pt with a normal angio w/in the past 2 years if quite unlikely to have developed significant epicardial stenosis

Answer 1

-

Question 2

A prior negative stress test means very little for predicting whether a pt presenting with c/p has ACS or not

Answer 2

plaque rupture is unpredictable and often occurs in lesions that were previously nonobstructive

Question 3

Treadmill test

Answer 3

-sensitivity 68%
-specificity 77%
for significnt coronary disease

Question 4

Stress echo

Answer 4

-80% sensitivity and 84% specificity for evaluating significant coronary disease

• NPV of low-risk ED pts for subsequent cardiac events is 97-100% (comparable to nuclear imaging techniques)
• detects wall motion abnormalities, assesses valves

Question 5

Thallium/nuclear imaging

Answer 5

Tracer uptake is directly proportional to regional myocardial blood flow
-limitations: timing is tricky, must use low doses b/c of risk for radiation exposure, artifactual perfusion defects in women and obese pts

-technetium has fewer limitations

Question 6

Cardiac MRI

Answer 6

-assess wall motion, perfusion, coronary atatomy

Question 7

CT coronary angiogram

Answer 7

-good for ruling out coronary dz in low-risk pts