2. Acute Coronary Syndromes Flashcards
Processes involved with CVS diseases (2)
Ischaemia
Infarction
Definition of ischaemia
Blood vessel narrowing
Ischaemia action (3)
Inadequate oxygen delivery for tissue needs
‘Cramp’ in affected tissue/muscle
No residual defect at first
Examples of ischaemic diseases (2)
Angina pectoris
Peripheral vascular disease (PVD)
Definition of infarction
Blood vessel occlusion
Infarction action (3)
No oxygen delivery, resulting in tissue death
More severe pain
Loss of tissue funciton
Examples of infarction diseases (2)
MI
CVA
Definition of angina pectoris (2)
Reversible ischaemia of heart muscles
Involves narrowing of one or more coronary arteries
Aetiology of angina
Narrowing and hardening of coronary arteries (atherosclerotic plaques)
Effect of angina (2)
Reduces blood supply to heart
Reduces oxygen concentration to heart
Mechanism of angina (3)
Reduced oxygen concentration to heart
Myocardial cells switch from aerobic to anaerobic respiration
This progressively impairs metabolic, mechanical and electrical functions
Cause of angina pectoris
Chemical and mechanical stimulation of sensory afferent nerve endings in the coronary vessels and myocardium (nerve fibres from T1-T4)
Different types of angina (2)
Classical
Unstable
Differences between classical and unstable angina (2)
Classical - worse with exacerbation/exercise
Unstable - more unpredictable, with symptoms seen at rest with no biomarkers
General angina symptoms (7)
Central, crushing chest pain/discomfort (tight, dully or heavy) Pain radiates to arm, back, jaw Breathlessness Nausea Feeling unusually tired Dizziness Restlessness
Classical angina symptoms (5)
No pain at rest Pain with certain level of exertion (cold weather) Pain relieved by rest Patient lives within limit of tolerance Gradual deterioration over time
Classical angina signs (2)
Often none
Occasionally, when not caused by atherosclerosis alone, hyper dynamic circulation
Components of hyperdynamic circulation
Anaemia
Hyperthyroidism
Hypervolaemia
Angina investigations (5)
ECG Eliminate other diseases (thyroid, anaemia, valve) Angiography Echocardiography Isotope studies (function assessment)
ECG results for angina (3)
Shows areas of myocardial ischaemia
Angina will appear as an ST segment elevation
AS angina worsens, ST segment will lower, finally showing as an ST segment depression
Angina treatment (2)
Reducing oxygen demands of the heart
Increase oxygen delivery to tissues
Methods to increase oxygen delivery to tissues (2) and descriptions (2)
Angioplasty/stenting - dilating blocked/narrowed vessels. Stretch artery back to normal size. Method of percutaneous intervention (PCI)
CABG (coronary artery bypass grafting) - bypass blocked/narrowed vessels
Non-drug angina therapies (2)
Explaining illness (learning to live within limitations) Modifying risk factors
Angina drug therapies (4) and example treatments (4)
Reduce MI risk - aspirin
Target hypertension - diuretics, Ca-channel blockers, ACE inhibitors, B-blockers
Reduce preload/dilate coronary vessels - nitrates
Emergency treatment - GTN
Definition of PVD
Angina of tissues, usually lower limbs
Cause of PVD
Due to atheroma in femoral/popliteal vessels
Complications of PVD (4)
Claudication in limbs on exercise
Limitation of function
Poor wound healing
May lead to tissue necrosis and gangrene
PVD management
As with angina
Infarction mechanism (3)
Atheroma in vessel causes thrombosis on surface which can rapidly enlarge, occluding the vessel
Atheroscerotic plaque detaches from vessel wall, travelling in the blood
Plaque blocks vessel, preventing blood flow
Where can infarction occur (3)
Coronary artery (heart) Femoral/popliteal artery (limb) Carotid artery (brain)
Types of infarction (5_
Spontaneous (primary coronary event) MI secondary to ischaemia Sudden death with symptoms of ischaemia and evidence of ST elevation/thrombosis MI from PCI MI from CABG
Strategy for treating infarctions (2)
Reducing tissue loss from necrosis (angioplasty/thrombolysis, CABG)
Prevent further episode (risk factor management, aspirin)
Definition of TIA
Transcient ischaemic attack - mini stroke of short duration (<24hrs)
Effects of TIA
Defects variable, usually causes loss of function
MI symptoms (5)
Pale Nausea Sweaty Pain radiates from chest/down arm Patient feels like they're going to die
MI investigations (2)
Cardiac enzymes - troponin measured as it leaks from dead cardiac muscle
MI ECG results
ECG - abnormalities vary in position with infarct, but may be normal
Primary care MI treatment (4)
Get patient to hospital
Administer analgesia and aspirin
Reassure patient
BLS if required
Hospital MI treatment (4)
Primary PCI (if within 3 hours)
Thrombolysis if indicated (if PCI unavailable)
Drug treatment to reduce tissue damage
Prevent recurrence/complications
Hospital care drugs
Aspirin
Thrombolysis (streptokinase, TPA)
Side effects of TPA
TPA will dissolve all clots, not just local clots
Thombolysis contraindications (8)
Injury Surgery IM injections Severe hypertension PUD Diabetic eye disease Liver disease Pregnancy
MI complications (6)
Death Arrhythmias HF Ventricular hypo function and thrombosis DVT and pulmonary embolism Thrombolysis complications
Medical management of MI (2)
Prevent next MI
Treat complications
Preventing next MI involves (4)
Modify risk factors
Aspirin
B-blocker (reduce excitability of heart and reduce arrhythmia effect)
ACE inhibitor
Combo. of aspirin, B-blocker, ACE inhibitor suggests patient is a previous MI sufferer
Treating complications include (3)
HF
Arrhythmias
Psychological stress
