Angina Flashcards
what is it
restricted perfusion of heart due to atherosclerosis
what is difference between stable and unstable angina
stable is on exertion
unstable (ACS) is angina of recent onset or worse at rest
what is the symptoms
tight, heavy, dull chest pain that passes within few minutes
radiate to left arm, neck, jaw or back
normally following exertion, stress, after meal or cold weather
what causes it
atherosclerosis due to hypertension, hyperlipidaemia, smoking, diabetes, age, sex
how is it diagnosed
symptoms ECG exercise tolerance test coronary angiography (assess coronary circulation) myocardial perfusion scinigraphy
what is ECG findings
between attacks - may be normal, or pathological Q waves (old MI), LVH/LBBB
during attacks - transient ST depression, t wave inversion
what is the treatment
GTN + secondary prevention (aspirin, ACEi and statin)
B blocker or CCB (verapamil) (if symptoms persist then B blocker + amlodipine)
If B blocker and/or CCB contradicted, give long acting nitrate or HCN channel activator or K+ activator
what is the mechanism of GTN (nitrate)
releases nitrate which are converted to nitric oxide which activates guanylyl cyclase, increasing cGMP. this cGMP activates PKG which relaxes vascular smooth muscle
The reduced [Ca2+], since more is taken up by SER, decreases MLCK activity and relaxation occurs due to reduced light chain phosphorylation
side effects of GTN
headaches, hypotension, syncope, tolerance
what is mechanism of aspirin (anti-platelet)
reduces platelet aggregation and arterial thrombosis by activating plasminogen to plasmin, dissolving thrombi
what are side effects of aspirin
bronchospasm, GI irritation, GI haemorrhage
what is mechanism of ACEI (lisinopril, ramipril, enalapril)
decrease synthesis of angiotensin II, a powerful vasoconstrictor, reducing vascular done (causing vasodilation)
what is the side effects of ACEI
dry cough, angiodema, proteinuria, neutropenia, renal failure, hyperkalaemia
what is mechanism of statins (atorvastatin, simvastatin, pravastatin)
HMG CoA reductase inhibitors - block cholesterol synthesis in liver. Compensatory mechanism incomplete and reduction of cholesterol in hepatocytes leads to increased LDL receptor expression, increasing clearance from plasma
what is side effects of statins
myopathy
what is mechanism of B blocker (bisoprolol)
block B-adrenoceptors
lower CO and decrease force of cardiac contraction
what are side effects of B blocker
cold hands, fatigue, provocation of asthma, heart failure, conductance block, nightmares
what is mechanism of calcium channel blockers (amlodipine, nifedipine, verapamil)
block L type calcium channels, preventing calcium from entering cells, causing relaxation of arteriolar smooth muscle (reduced TPR so BP falls)
what is side effects of CCB
dizziness, hypotension, flushing, ankle oedema
what is mechanism of long acting nitrate (isosorbide mononitrate)
same as GTN
what is mechanism of HCN channel inhibitor (ivabradine)
reduces HR via specific inhibition of funny current
what is mechanism of K+ activator (nicrorandil)
potassium channel activator with nitrate component which has arterial and venous vasodilating properties
what surgeries can be considered in angina
PCI and CABG
what is PCI
dilation of coronary artery using ballon and stent inserted via femoral/radial/brachial artery
patient must be anticoagulated and antiplateleted beforehand
