coronary artery disease Flashcards
generally speaking what is CAD ?
condition where there is narrowing or blockage of the coronary artery
what is the principle cause of CAD ?
atherosclerosis
what is the pathogenesiiss behind atheerosclerotic heart diisease ?
plaque buildup in coronary arteries
progressive narrowing which leads to ischemia
the narrowing eventually leads to blockage and infarction
what are the modifiable risk factors of CAD ?
smoking and tobacco use
diabetes
hypertension
physical inactivity
obesity
dyslipidemia
what are the 2 main coronary arteries ?
the left coronary giving the circumflex and the left anterior descending
the right coronary artery gives the marginal branch
what areas are supplied by the right coronary artery ?
right atrium and hence the SA node
right ventricle
interventricular septum and hence the AV node
what does the marginal branch off the RCA supply ?
the apex of the heart
what does the LCA supply ?
left atrium
left ventricle
interventricular septum and hence the AV bundle
what does the left circumflex artery supply ?
Supplies the left atrium and the posterolateral surface of the left ventricle
when does myocardial ischemia happen ?
when there is an imbalance between the supply of oxygen and the myocardial demands
what are the two main broad reasons for thee causes of IHD ?
increased demand of oxygen
decreased blood supply ( decrease in quality of quantity )
what is angina ?
transient clinical syndrome due to transient myocardial ischemia , characterized by chest pain with no cardiac tissue damage
what is the clinical presentation/ spectrum of prressentation of IHD ?
asymptomatic
angina
MI
HF
arrhythmia
sudden death
what are the three types of acute coronary syndrome ?
unstable angina
STEMI ( full thickness )
non STEMI ( non full thickness I )
what is the pathophysiology behind unstable angina?
rupture of an atheroscclerotic plaque and the subsequent formation of a thrombus
what are the criteria that need to be fulfilled for unstable angina ?
1- onset (<6 weeks) angina at exertion or at rest.
2-Angina at rest in previously exercise-induced angina.
3- Exertional angina that is not responding to increasing anti-anginal medications.
what is stable angina ?
occurs when coronary perfusion is impaired by fixed stable atheroma of the coronary arteries
no symptoms at rest
no ecg changes at rest
provoked by exercise
what is variant angina ?
also known as prinzmetal angina
angina with normal coronary arteries
what are the clinical features of stable angina?
chest pain , increased by exertion
decreased by rest or nitrates
what are the clinical features of variant angina ?
happens usually at rest
often between midnight and early morning
in association with ST segment elevation
what is the first line investigation in CAD ?
CT coronary angiography
what is the 2nd line investigation for CAD ?
myocardial perfusion scan ( Iv thallium )
stress echocardiography
what is the 3rd line investigation for CAD ?
invasive coronary angiography
what are the lab investigations for CAD ?
- CBC, U&E, Creatinine, ESR
- Cardiac enzymes (high sensitive troponin)
- Lipid profile
- Blood sugar
what are the ECG changes that indicate ischemia ?
pathological q wave
inverted t wave
st elevation
what does echocardiography show us ?
any ventricular abnormalities
evidence of structural abnormality
what are the indications for Percutaneous coronary angiography
diagnostic : assessment of coronary vessels
therapeutic : angioplasty
stent insertion
what is the coronary calcium score ?
low coronary calcium score makes the presence of CAD unlikely
high coronary calcium score makes CAD likely
all within the next 2-5 years
a low score is 0
a high score is above 100
what are the side effect of nitrates ?
flushing
headaches
hypotension
what must be taken into consideration when using nitrates ?
sildenafil ( viagra ) should not be used at the same time
how do beta blockers work for CAD patients ?
reducing heart rate
reducing BP
reducing myocardial contractility
what is b blocker withdrawal syndrome ?
they should not be withdrawn abruptly as rebound effects may worsen condition
what is the mechanism of actionn of nitratess ?
1- act direectly on vascular smooth muscles andd cause vasodilatation
2- reduce myocardiall oxygen demand by lowerring preload and afterload
common side effects of beta blockers ?
bradycardia
hypotension
bronchoconstriction
cold extremities
impotence
what are the indications for nitrates ?
angina
what are the indications for the use of calcium channel blockers ?
hypertension ( amlodipine)
angina
supraventricular tachycardia ( verapamil )
what are the side effectss of ACE and ARBs ?
dry cough
postural hypotension
hyperkalemia
nausea
renal impairment
what drug does not exhibit the tolerance seen with nitrates ?
nicorandil ( potassium channel activators )
what is the management for angina ?
1- confirm that the patient is cardiac
2- determine if its stable or unstable angina
what are the results of cardiac enzymes / troponin ?
unstable angina - negative
NSTEMI - positive
STEMI - positive
what are the ECG changes for each of the presentation of ACS ?
unstable angina - ST depression
NSTEMI - ST depression
STEMI - ST elevation or new LBBB
what are the types of MI ?
STEMI ( trans-mural)
NSTEMI ( sub-endocardial)
what are the sites of MI in STEMI ?
anterior wall infarction : in anterior descending branch
lateral wall : left circumflex artery
inferior wall : right coronary artery
what are the complications of cardiac tamponade ?
pulmonary edema
shock
death
what are the late complications of myocardial infarction ?
myocardial aneurysm and remodelling
pericarditis
what is seen on examination of a patient with pericarditis ?
friction rub
what is the first line therapy for reperfusion ?
Primary Percutaneous Coronary Intervention
and give fibrinolysis before PCI
what is the best next step in management if PPCI is unavailable for reperfusion therapy ?
thrombolysis
what are the contraindications to thrombolysis use ?
previous history of stroke
suspected aortic dissection
intracranial neoplasm
what drugs aree commonly used post MI ?
antiplatelet
ACE inhibitors
ARB
beta blockers
statins
what is the most common complication following pericardiocentesis procedure ?
pneumothorax so an Xray must be performed
what are the two types of CCBb ?
DHP - for hypertension
non DHP - morre cardio-selective
what are the contraindications too CCB ?
heart failure ( except amlodipine )
concurrent beta blocker usage
severe hypotension
