Angina Flashcards
What is angina?
- cardiac chest pain
- discomfort in chest associated with myocardial ischaemia but without myocardial necrosis
Describe the mechanism of angina
- mismatch between supply of O2 and metabolites to myocardium and myocardial demand for them
- normally due to reduction in coronary BF to the myocardium
Causes of stable angina
- obstructive coronary atheroma
- coronary artery spasm ( uncommon)
- coronary inflammation/artertisi(rare)
- reduced O2 transport ( anaemia) [ uncommon]
- pathologically increased myocardial O2 demand ( LVH, significant aortic stenosis and hypertrophic cardiomyopathy)
- Thyrotoxicosis
Most common cause of atheroma
- coronary atheroma
- On activity? with the increased mycardial O2 demand, obstructed coronary blood flow leads to myocardial isachaemia then symproms of angina
- myocardial O2 demand increases in situations where HR and BP rise; excercise, anxiety/emotional stress after a big meal
Stable angina
- myocardial isachaemia causing angina pectoris
- precipitated by excess myocardial O2 demand ( exertion, cold weather, emotional stress, after heavy meal)
- pain in LHS chest region, and left arm
Site, character, radiation sites of pain - Stable angina
site ; retrosternal
character of pain = tight band/pressure/heaviness
radiation sites; neck and/or jaw, down arms
Sometimes on extertion:
- breathlessness
- excessive fatigue on exertion for activity taken
- near syncope(faint) on exertion
More often in the elderly or those with diabetes mellitus: probably due to reduced pain sensation. ?
SHOULDNT BE
-localised pain
-lasting for hours
-sharp stabbing pain ( pleuritic/pericardial)
-assoc with body movements/
Relieving factors of stable angina
-rapid improvement with GTN/physical rest
Differential diagnoses for chest pain
Cardiovasular causes:
aortic dissection, pericarditis
Respiratory: pmeumonia, pleurisy, peripheral pulomary emboli ( pleuritic)
Muscoskeletal: cervical disease, costochrondritis, muscle spasm, strain
GI causes: gastro-oesophageal reflux, osophageal spasm, peptic ulceration, bilary colic, cholecytitis, pancreatitis
Risk factors for coronary artery disease
- age, gender, creed?, FX, genetic factors
- Smoking, lifestyle (diet/excercise), diabetes mellitus( glycaemic control reduces CV risk), hypertension (BP control ‘’’’) , hyperlipidaemia ( lowering reduces risk)
Stable angina - Examination
- tar staining of fingers
- obesity (centripedal ), Xanathalasma and corneal arcus ( hypercholesetrolaemia)
- hypertension, abdominal aortic aneurysm arterial bruits, absent/reduced peripheral pulses
- diabetic retinopathy, hypertensive retinopathy on fundocscopy?
Signs of exaceerbating/associated conditions
- pallor of anemia
- tachycardia, tremor, hyper-reflexia of hyperthyroidism
- ejection systolic murmur, plateau pulse of aortic stenosis
- pansystolic murmur of mitral regurgitation
- signs of HF ( basal crackles, elevated JVP, peripheral oedema)
Investigations for stable angina
- Bloods
- CXR
- electrocardiogram
- excercise tolerance test ( ETT)
- myocardial perfusion imaging
- CT coronary angiography
-cardiac catherterisation/cornorary angiography
Invasive angiography if:
- early/postiive ETT ( suggests multi vessel ds?)
- angina refractory to medical therapy
- daignosis not cear after non-invasive tests
- young cardiac patients work
- occupation/lifestyl with risk ( dirvers etc)
Investigations of stable angina - Bloods
- FBC
- lipid profile
- fasting glucose
- electrolytes
- liver and thyroid tests
Investigations of stable angina - CXR
may show pulmonary oodema/other causes of pain
Investigations of stable angina :Electrocardiogram
- evidence of prior myocardial infarction ( ie pathological Q-waves)
- evidence of left ventricular hypertrophy ( ie high voltages, lateral ST-segment depression/ ‘‘strain pattern’’
Investigations of stable angina - excercise tolerance test
- walking to produce sufficient CV stress
- if negative at high workload, prognosis is good
Investigations of stable angina - myocardial perfusion imaging
- can detect CAD, localise isachaemia + assess size of area affected
- requires radioactivity
- either excercise or pharmacological stress: adenosine, dipyridamole, dobutamine
Investigations of stable angina - cardiac catheterisation/coronary angiography
- shows, sites, distribution and nature of atheromatous disease
- allows decision on what treatment is best
- whether medication alone/percutaneous coronary intervention and stengting or coronary artery bypass graft surgery
- done under local anaesthetic
- arterial cannula inserted into femoral/radial artery
- coronary catherters passed to aortic root + itnroduced into ostrium of coronary arteries
- radio-opaque contrast injected down coronary arteries and visualised on x-ray
What is an invasive coronary angiography?
a 2D ‘lumenogram’’ as iodinated contrast/dye is passed through arteries
Atheroma in an invasive coronary angiography
views in different planes as atheroma is eccentric in natture
-?? shows stenosis in mid right coronary artery, amendable to angioplasty
Treatment strategies for treatment for stable angina
General
-address risk factors ( BP,c holesterol, DM, lifestyle)
Medical treatment
Revascularisation ( if symptoms not controlled)
-percutaneous coronary intervention + coronary artery bypass grafting
Treatment of stable angina
Influencing disease progression:
- Statins
- ACE inhibitors
- aspirin
For relief of symptoms:
- Beta blockers
- Ca2+ channel blockers
- Ik channel blockers
- Nitrates
- K+ channel blockers
Treatment of stable angina- Statins
- consider if total cholesterol > 3.5mmol/L
- Reduces LDL-cholesterol depositiation in atheroa and stabilises atheroma reducing plaque rupture and ACS?
Treatment of stable angina- ACE inhibitors
- if increased CV risk + atheroma
- stabilises endothelium + reduces plaque rupture
Treatment of stable angina: Apsirin
- 75mg/clopidogrel if intolerant to aspirin
- may not directly affect plaque but protects endothelium + prevents platelet activation/aggregation
Treatment of stable angina - beta blockers
- achieve resting HR < 60bpm
- reduced myocardial work + antiarrythmic effects
Treatment of stable angina - Ca2+ channel blockers
- achieve resting HR < 60bpm
- central acting ( diltiazem/verapamil if Beta blockers C-I
- produce vasodilation; peripherally acting dihydropyridines ( amlogipine, feldodipine)
Treatment of stable angina- Ik channel blockers
- achieve resting HR < 60bpm
- ivabridine reduces sinus node rate
Treatment of stable angina - K+ channel blockers
- nicorandil
- nitrate molecule + K+ channel helpful in preconditioning?
Treatment of stable angina - percutaneous coronary intervention
- similar beginnings to coronary angiography but cross stenotic lesion with guidewire and squash athermoatous plaque into walls with ballone and stent
- if stent used, aspirin and clopidogrel taken together whilst endothelium covers stent struts and is no longer seen as a foreign body with associated risk of thrombosis
Risks of PCI
-RETONOSIS
Risks of PCI
-Retonosis
Treatment of stable angina - coronary artery bypass surgery
- in diffuse multi vessel CABG best option for stable angina
- patients must continue disease modifying medication and predicatble detiorartion in vein grafts after 10yrs
