CAD Flashcards
definition of CAD
coronary artery dz - narrowing or blockage of arteries and vessels that provide oxygen and nutrients to the heart
definition of CVD
cardiovascular dz - broader category which includes CAD, arrhythmias, stroke (CVA) and heart valve disorders
definitions of atherosclerosis
buildup of plaque (choesterold, fat, calcium) withing blood vessles
definition of angina pectoris
dz marked by brief paroxysmal attacks of chest pain precipitated by deficient oygenation of the heart muscles
myocardial O2 demand exceeds supply which is reveresed by decreasing demand
definition of MI
myocardial infarction
heart attack further differentiated into
STEMI (ST segment elevation MI)
or NSTEMI (non ST segment MI)
etiology of CAD
significances of age, sex, incr BP, cholesterol, and obesity in predicting future CHD
Framingham Coronary Heart Dz risk score
risk factors for males
total cholesterol HTN smoking low HDL diabetes age
risk factors for females
low HDL diabetes total cholesterol HTN age smoking
CAD factors unique to women
- smaller coronary arteries and less developed collateral cirucation = symptoms with less occlusion
- elevated inflammatory state with loss of estrogen - risk doubles 10 years over 55yo
- lower baseline HDL levels
- vague symptoms are the norm = 50% report no pain, OSB MC, other symptoms include: fatigue weakness, palpitations, midback pain
- less symptoms relief with treatments and poorer outcomes from CABG
- higher rates of post MI heart failure
cigarette smoking
1 preventable cause of death and illness in US including 2nd hand smoke
- risk of CAD decreases by 50 % after cessation x 1 year; 10-15 yr until same as nonsmoker
- CO high affinity to bind to hemoglobin: decr O2 binding capacity and release of O2 = incr RBC mass resulting in hypercoagulable state
- inhalation of CO reduces threshold for Vfib
- nicotine increases HR by avg 7 beats/minute
- oxidizing chemicals and metals cause inflammation, endothelia dysfunction, lipid abnormalities, and platelet activation
- end result = incr demand, decreases O2 to tissues, hypercoag state, damaged endothelium
CAD and lipids
LDL cholesterol: main component in atherosclerotic plaques
TGs: lipid made from converting foods high in carbs or fat; also component of plaques
HDL cholesterol: absorbs other cholesterol and carries it back to liver; can reduce risk of heart dz and stroke
CAD and diabetes
- diabetes tends to lower HDL and raise triglyceride and LDL
contributes to hypercoagulable state: increased fibrinogen and plasminogen activator inhibitor -1 and various platelet abnormalities
nephropathy leading to cardio-renal syndrome
neuropathy allows multi vessel atherosclerosis to develop before ischemic symptoms occur resulting in cardiomyopathy
CAD and HTN
causes microscopic tears to artery walls allowing for accumulation of atherosclerosis
causes decreased elasticity of arteries resulting in increased afterload leading to more strain on the heart resulting in cardiomyopathy
CAD - sleep apnea
- paused or shallow breathing while sleeping
- obstructive most common vs central, generally associated with obesity
- increased negative intrathoracic pressures increases after load resulting in increased demand in an already hypoxemic state
- pro-inflammatory and oxidative state promoting atherosclerosis
- increased platelet activity and reduced fibrinogen promoting thrombus
- up to 40% of pts with CAD have sleep apnea, generally under considered when working up CAD = question partner about snoring or apneic events while sleeping
rx: sleep study if suspected, CPAP
hx to determine stable vs unstable angina
- aggravating
- relieving - aggravating
- descriptors
- location/radiation
- frequency/duration
hx often determine angina
- exertion (? less activity required)
- supine (incr preload)
- emotional stress
- am symptoms (incr sympathetic NS tone and cortisol elevls during this time can lead to the rupture of cholesterol plaques in coronary arteris ultimately leading to a four fold higher risk of heart attack early in the morning)
- post prandial or cold exposure (vasoconstriction)
- intercourse
hx to determine angina vs unstable angina - relieving
how long after cessation of aggravating factor does pain - descriptors resolve? generally stops
hx to determine stable vs unstable angina
tightness, squeezing, burning, pressing, choking, aching, gas busting or tearing usually associated with thoacic aneurysm
hx to determine stable vs unstable angina - location/radiation
clenched fist over chest, substernal or left sided, loess frequently right sided, radiates to shoulder arm neck jaw back or abdomen
hx to determine stable vs unstable angina - frequency/duration
how often or number of incidence increasing, longer duration more likely unstable angina or MI
CAD epidemiology
#1killer of US women, greater then all forms of cancer combined usual onset M>45 F>55 CAD is leading global cause of death
exam to differentiate stable vs unstable angina
- cardiac murmurs: mitral prolapse, AS, AR
- diabetes: retinopathy, neuropathy
- hypercholesterolemia: xanthelasma
- hypothyroid: myxedema (cardiomegaly, fluid retention, bradycardia, lethargy)
- peripheral artery dz: claudication, diminished pulses, lower ext atrophy, extremity hair loss or thinning of skin, rub of feet w/ blanching on elevation
- active angina - hypertensive gallop rhythm, tachy-arrythmias, mitral regurg, diaphoretic, restless
w/u for CAD
- risk stratification: framingham, ascvd, QRISK, HEART, reynolds
- labs: CBC, chem7, lips, a1c, cardiac enzymes, crp,
- ekg: normla, LVH, ST elevations/depressions, t inversions during pain
cxr: normal or cardiomegaly, assess for non cardiac etiology
CRP levels and CAD risk
3x increased risk o of heart dz with elevated levels
CAD and stress test
- exercise stress is most common,
- utilizes bruce protocol which increases treadmill speed/elevation q3min while monitoring ekg for changes - pharmacologic stress uses dobutamine or adenosine rather then exercise to elicit angina or ischemia
- stress echo - adds ultrasound to eval for wall motion abnormalities
indications for stress test
contraindications
- confirm dx, determine severity and prognosis, eval response to tx
- pain at rest or with minimal activity, AS
positive test in stress test for CAD
1mm horizontal or down sloping ST depression measured 80 msec past the j point
echo indication for CAD
clarification if underlying ekg changes, confirmation if possible false positive exercise, ischemia vs infarcted, tx response, monitor for dz progression