CV 7 IHD Flashcards
ECG is a – method of evaluating the electrical activities of the heart
direct
standard ECG provides a –
60 sec recording
Abnormalities in cardiac cycle present as – in ECG
changes in length and amplitude of electrical waves
different leads provide different views of –
same electrical event
incidence of IHD
7 million people
incidence of MI
1.5 million people
myocardial oxygen demand in excess of supply
ischemia
continued ischemia leading to muscle damage
infarction
coronary arteries and capillaries usually have – resistance unless occluded
low
sense mechanical forces and regulates vascular tone
endothelium
protective cholesterol
HDL
best predictor of atherosclerotic heart disease
total cholesterol to HDL ratio (ideal is 3.5 and lower)
– has antifibrinolytic properties and an increase in – correlates with heart disease
lipoprotein
homocysteine (sulfur) excess has direct toxic effect on – interfering with clotting factors and promotion of LDL
endothelial cells
what can correct homocysteine excess?
folic acid
what is a marker of systemic inflammation?
C-reactive protein
Strongly correlated with risk of MI, stroke, peripheral arterial disease, and sudden cardiac death
C-reactive protein
what is emerging as an important risk factor
inflammation
Atheroma evolution: innate and adaptive inflammation in atherogenesis
foam cells release proinflammatory cytokines
Atheroma evolution: smooth muscle cells
migration and proliferation –> cell death
Atheroma evolution: arterial ECM
collagen deposits –> outward growth of intima
Atheroma evolution: angiogensis
plaque neovessels
chronic atherosclerosis
arterial stenosis, gradual occlusion and limited flow
acute atherosclerosis
disrupted plaque, rupture, and thrombosis
example of chronic disease
stable angina
example of acute disease
acute coronary syndrome
pain of cardiac ischemia
pressure, squeezing, burning
pain may radiate to –
left shoulder, jaw and arm (lower back for women)
no symptoms present, occurs commonly and mortality as high as with pain
silent ischemia
duration of stable angina
2-10 min
duration of unstable angina
< 20 min
duration of MI
> 30 min
nausea, vomit, cold sweat, SOB is associated with –
acute ischemia
heart sounds for cardiac ischemia
distant, gallop rhythms, occasional murmurs
cardiac ischemia’s effect on lungs
rales
what is the most important element of diagnostic work up of acute vs chronic ischemia?
history
evidence of MI on EKG
abnormal ST and T wave
Limitations of EKG: when combined with – for ischemia work up, sensitivity is only about 65% while specificity is 90%
exercise
when diagnosing an infarction –
changes in heart may take days to dev
myocardial perfusion diminishes with ischemia
nuclear cardiology
abnormal wall motion from ischemia or infarction
echocardiogram
demonstrates vessel obstruction
coronary angiography
most commonly used nuclear cardiology test
SPECT scan
SPECT scan: radioactive tracers are – and images are obtained with heart at rest or after exercise
injected IV
because radioisotope concentration in myocardium depends on perfusion rate, SPECT scan shows –
ischemia
the-99
emits high photon (short 1/2 life)
tha-201
emits low photon (long 1/2 life)
shows presence of absence of perfusion and quantitative measurement of myocardial perfusion and metabolism
PET scan
PET scan uses isotope tracers tagged to a glucose analog and have very –
short 1/2 lives
what is the gold std
coronary angiography
blood tests are useful tests for –
infarction
useful screening for silent ischemia?
ambulatory EKG
angioplasty usually takes –
1 day
coronary artery bypass graft surgery or CABG takes –
a couple of days (open heart surgery)
ischemia can lead to –
contractile dysfunction
arrhythmia
infarction
blood test showing – is a sign of infarction
cardiac troponin and creatine kinase MB isoenzyme
send balloon catheter to stretch coronary vessel
coronary angioplasty
do NOT use AB prophylaxis after 6 months of bypass surgery because –
stint may embolize –> another MI
