CAD: Diagnosis Flashcards
type II error
false negative
type I errors = ?
false positives
Target HR in stress test
85% of age predicted HR (220-age)
Rate Pressure Product
peak HR x SBP
measures myocardial workload
Sn and Sp of ETT
both around 70%
on ETT does ST elevation or depression localize ischemia?
ST elevation does
ECG changes prognostic on ETT
- max ST depression
- # leads involved
- time to ST shift
- recovery time
- inducible ventricular arrhythmias
Hemodynamic changes prognostic on ETT?
- peak HR (Chronotropic incompetence)
- BP (exercise induced hypotension)
- rate pressure product
what does exercise induced hypotension on ETT mean?
LM or 3VD
Are HOCM, high degree AVB, severe HTN absolute contraindications to ETT?
no
at what high BP do you stop a ETT?
250/115
absolute reasons to stop an ETT (7)
1- ischemia w/ SBP dec by 10mm Hg 2- mod-sev angina 3- CNS sxs 4- cyanosis/pallor 5- sustained VT 6- >1mm ST elev (other than V1 or aVR) 7- pt requests
which conditions obscure ST changes on ETT?
WPW PPM ST dep 1mm at rest LBBB LVH Dig
ST depression in which leads of an ETT don’t matter?
V1, aVR
ST Elevation on ETT
Should be in leads without Q waves
Transmural ischemia from coronary spasm or myocardial injury
Duke Treadmill Score
Exercise time (mins) - (5 x mm ST dep) - (4 x angina index)
Angina index
0- no CP
1- CP
2- CP stops exercise
Scores and corresponding mortality for Duke treadmill
Low risk > 5 (0.5%)
Intermediate risk +4 to -10 (.5-5%)
High risk < -11 (>5%)
HR reserve and chronotropic incompetence
HR Reserve = 220-age-resting hR
Chron. incomp is inability to inc HR by 80% of HR reserve
what is considered a low level of exercise?
HR<70% max HR
differences in SN/Sp b/w stress echo and nuclear
similar Sn
stress echo- higher Sn (fewer false +)
adenosine stress MOA
A2A receptor agonist–> 4x inc in coronary blood flow
adenosine effect on HR and BP
inc HR
modest dec in BP
*adenosine side effects by receptor-type
A1 : AVB
A2b: periph vasodilation, bronchospasm
A3: bronchospasm
adenosine stress contraindication (5)
asthma/COPD high degree AVB/SSS w/o PPM SBP<90 recent dipyridamole/aggrenox on methyl xanthones (aminophylline, caffeine) w/in 12hrs
regadenoson receptors
binds selectively to A2A receptor
- low affinity for A1, A2b, A3 so less side effects
persantine (dipyridamole) stress test MOA
indirectly increases adenosine by preventing its reuptake
dobuatmine stress dosing
5-10 mcg/kg/min, inc q3min to 20/30/40 mcg/kg/min
atropine .25mg IV q2min upto 1-2mg
dobutamine antidote
short acting IV BB
Dobutamine stress absolute contraindications
symptomatic severe AS
acute Ao dissection
ACS
HOCM
absolute contraindications to atropine
myasthenia gravis
narrow-angle glaucoma
pyloric stenosis
does dobuta stress have good PPV or NPV?
NPV
what type of contraindications are recent ventricular arrhythmias and high degree AVB for dobuta stress?
relative
4 Class I indications for angiography
1- CCS class III/IV angina on meds 2- high risk stress test 3- SCD 4- sustained MONOMORPHIC VT (>30s) 5- non sustained POLYMORPHIC VT (<30s)
CCS classification for angina
I- can do normal physical activity (angina only w/ a lot of exertion)
II- slight limitation w/ normal activity (running up stairs, emotional stress/morning hours/uphill)
III- marked limit. 1 flight of stairs.
IV- unable to do activity. Rest angina.
intermediate risk Duke treadmill score
-11 to 5
what category of risk is inc’d lung uptake on stress test?
high
> ? segments on stress echo with low dose dobuta is high risk?
> 2 segments
if a pt has DM, 2VD + pLAD, is it Appropriate to do PCI?
yes
for which of the following is it Appropriate to do CABG in DM: 2VD +pLAD, 3VD, LM Dz, or LM + 1VD?
All
in asxs pt’s w/ no known CAD, when is it APPROPRIATE to do cardiac CT?
family hx of premature CAD and low to intermediate risk of CHD
is it APPROPRIATE to do a cardiac CT on a symptomatic pt. to assess stent patency
no
in pt’s w/ CM, when is it APPROPRIATE to do a cardiac CT?
low-intermediate CHD risk
when is it APPROPRIATE to do a cardiac CT for atrial or ventricular arrhythmias?
never
what conditions to use cardiac CT to assess structure and fxn?
congenital heart dz RV fxn Arrhythmogenic RV dysplasia pericardial anatomy PV anatomy (afib ablation) localization of CABG grafts pre thoracic Sx
what to look for on CMR to assess myocardial viability?
late gadolinium enhancement
what is considered a positive EKG on ETT for ischemia if baseline EKG has <1mm ST depression?
> 2mm ST depression (horizontal or downsloping)
if a patient has ventricular ectopy/bigeminy, etc. on ETT, what is its significance if it happens during a) exercise b) recovery
a) decreased LVEF
b) decreased LVEF and inc’d mortality
persantine contraindications are same as adenosine plus what?
liver failure b/c of hepatic metabolism
if pt has normal nuclear with strongly positive exercise EKG or angiographic stenosis, what is their cardiac event rate per year?
<1%
what is TID due to?
subendocardial ischemia
can cardiac CT or MR be used to screen for CAD?
no
what perfusion defect percentage at rest or stress is considered high risk (>3% death/MI per yr)?
10%
what CAC score is high risk?
> 400
Class I rec for noninvasive imaging in asymptomatic pt’s
none
if ETT already done, when is it appropriate to do CTA?
intermediate risk
