CHD Flashcards
Left main artery
aka left coronary
branches to left anterior descending (LAD) and circumflex
right coronary artery
RCA
to base and anterior wall
RA and RV
LAD
left anterior descending
LA- front and septum
circumflex
from left coronary
LA and LV- back and side
CHD
athersclerosis - endothelial injury causes smooth m. proliferation, inflammatory cell recruitment and lipid deposition within the vessel
plaque progressively narross the coronary artery lumen impacting blood flow
unstable plaque ruptures and exposes throbogenic core of lipid and necrotic material to platelets that adhere and aggregate causing ACS
10 yr risk of CHD event > 20%
noncoronary artheroscerotic disease - carotid artery disease, PAD, AAA
DM
CKD
CHD: risk factors
Fhx - MI/death of 1st degree relative 45 (M), >55 (F) gender- men, women after menopause Elevated hs-CRP metabolic syndome obesity elevated blood homocysteine levels low intake fruit/vegetables/fiber and high intake of red meat/glycemi index foods physical inactivity psychosocial factors - stress, depression estrogen deficiency oral contraceptives cocaine
framingham risk calculator
uses age, gender, SBP, cholesterol, HDL, BP meds, smoking status
CHD symptoms
often asymptomatic CP/angina arm, shoulder, neck, back of jaw pain dyspnea w/ or w/o exertion syncope or presyncope weakness dizziness/lightheadedness fatigue palpatations/ arrhythmias SCD HF - dyspnea, orthopnea, wt gain, edema
CHD PE
often normal
may have bruits - PVD
abnormal ABI/ weak lower extremity pulses - PAD
HF - peripheral edema, S3, ascites, rales, JVD, HJR
Stable angina pectoris
usually causes by CHD, oxygen demand exceeds supply
CP- heavy, pressure, squeezing, burning, fullness, elephant on chest, may radiate to shoulder, arm, neck, jaw
does not change w/ position or inspiration
palpatation causes no additional discomfort
Also - SOB, nausea, diaphoresis, lightheaded, fatigue
discomfort occurs w/ activity and resolves w/ rest
same discomfort every episode
nitroglycerin shortens or aborts attack
stable angina pectoris PE
incr. in HR, BP - sympathetic activation
S3, S4, paradoxical splitting of S2
New/changed murmur- papillary m. dysfcn
stable angina pectoris tests
Labs - lipid, CMP, CBC, TSH
troponin/ CK-MB
CXR- should be no findings
resting EKG - not sensitive or specific but during anginal episode, characteristic ST depression
echocardiogram
ultrasound
ability to evaluate cardiac anatomy and function
evaluate LVEF - +50% normal
can show wall motion abnormalities indicative of S/P MI or active ischemia
exercise stress test
evaluate continue EKG w/ exercise
look for ST depression of 1 mm or greater
ability to monitor BP, functional capacity, monitor for exercise-induced symptoms and arrhythmias
cannot use for abnormal resting EKG - ST depression, NSST changes, LBBB or paced
no radiation
stress echocardiogram
provides an ultrasound evaluation of cardiac function pre- and post-exercise
normal study - hypercontractility of all walls post exercise
abnormal - one area has poor movement or hypokinetic
difficult on pts with large body habitus
no radiation
dobutamine stress echocardiogram
increases contractility of the heart (+ inotropic agent)
ordered only for pts unable to exercise and have significant COPD/ asthma with active wheezing
highly symptomatic - feel like having heart attack - CP, dyspnea, palpitations, HA, nausea
Nuclear stress test
visualize radiopharmaceutical pre and post exercise
can calculate LVEF
can tell if viability fixed (post MI) or reversible (active ischemia)
modest radiation exposure, high cost
may see balanced perfusion in 3 vessel disease but generally fairly accurate
chemical nuclear stress test
for pts that cannot exercise to target HR, lexiscan used
contraindications - pregnancy, AV blocks (not 1st), sinus node dysfcn, active wheezing, BP <90/60
common SE - bronchoconstriction, hypotension, dyspnea, CP, nausea, flushing, abd pain, HA, dizziness (usually brief)
Stress Test contraindications
acute MI, unstable angina pectoris
uncontrolled arrhythmias causing hemodynamic compromise symptoms
symptomatic sever vavlular stenosis - aortic esp.
uncontrolled, symptomatic HF
active endocarditis, acute myocarditis, pericarditis
aortic dissection
PE or systemic emboli
acute disorders that exercise may aggravate
pregnancy - nuclear/pharm only
stress test info
exercise to target HR - 85% of max for age (220-age*.85)
LBBB or paced rhythm should be pharm testing only
drop in SBP indicates stenosis including left main disease
be prepared for the worst - staff and equipment
consider radiation exposure if done often
