Flashcards in Angina (stable + Unstable) Deck (9):
Rarely anaemia, tachyarrhythmia, arthritis, small vessel disease.
Central chest tightness or heaviness.
May radiate to arms, neck, jaw, teeth.
Triggers- exercise, emotion, cold weather, heavy meals.
-stable- induced by exertion, relieved at rest or by nitrates in 5 mins.
-unstable- increasing frequency or severity on minimal exertion or at rest. Longer duration. No relief by nitrates. High risk MI.
-decubitus- precipitated by lying flat.
-variant- caused by CA spasm.
ECG usually normal, may show STD, flat or inverted T, signs of past MI.
Exclude eg anaemia, DM, hyperlipid, thyrotoxicosis, temporal arthritis.
Aspirin reduce platelet aggregation.
BB reduce HR and contractility.
Nitrates- GTN acutely, isosorbide mononitrate prohpylaxis oral. Reduce preload by venodilation.
Long acting Ca antagonist reduce afterload by peripheral vasodilation.
K channel activator
Statins reduce LDL
Revascularisation- PCI or CABG
Coronary blood flow
Epi to endocardium.
So subendocardial muscle most vulnerable to ischaemia.
CA's compressed during systole so most CA flow during diastole, which is shortened more at high HR.
No collaterals between major As, some between smaller CAs and arterioles. New ones develop with ischaemia slowly.
Plaques necrotic centre and fibrous cap.
Stable- thick cap, small necrotic core.
Vulnerable- large necrotic core, thin cap. More likely fissure= platelet clot then fibrin thrombus.
ACS= unstable angina, NSTEMI, STEMI.
Unstable angina eg just platelet agrregation.
NSTEMI eg small thrombus
STEMI eg thrombus occlusion complete.
RFs eg HTN, corneal arcus, PVD absent pulses.
Resting ECG normal.
Exercise ECG transient subendocardial ischaemia= STD. Positive test if STD over 1mm. Negative if target HR w/o ECG changes