- ACUTE CORONARY SYNDROMES - Flashcards
Define Coronary Artery Disease (CAD)
An impedance or blockage of on or more arteries that supply blood to the heart, usually due to atherosclerosis
Outline the pathophysiology of CAD
- Endothelial dysfunction results in increased permeability, allowing excess LDL to accumulate in the intima, a chemical reaction occurs in the intima making them oxidised LDL
- Stimulation of the endothelial cells from reaction results in diffusion of lipids and inflammatory cells (monocytes and T lymphocytes) into endothelial cells and subendothelial spaces
- Monocytes and macrophages produce inflammatory mediators
- Macrophages ingest O-LDLs and become fat lade and frothy; these are called foam cells
- Foam cells form fatty streaks and promote the migration of smooth muscle cells from the tunica media to the tunica intima and this causes smooth muscle cell proliferation
- Increased SMC proliferation results in increased synthesis of collagen, which hardens plaque and forms a fibrous cap over lipid core, protruding into lumen
- Foam cells die and release lipid contents resulting in the formation of plaque
- With increased turbulance around protruding plaque, from HTN or increased cardiac workload, the plaque may rupture, releasing its contents.
- The clotting process is initiated to contain lipid contents
- Thrombus is formed and platelets adhere to the thrombus
- Thrombus then inhibits blood flow/ O2 supply to the heart
- ishccaemia/infarct
Discuss the pharmacological management of patients with chest pain
- Aspirin (antiplatelet to reduce platelet aggregation and thrombus formation)
- GTN (vascular smooth muscle relaxant - reduces preload and afterload and thus reduces O2 demmand)
- Morphine ( reduces SNS stimulation resulting in a decrease in catecholamine realease and thus reduces O2 demmand. Also works as a vasodilator)
Discuss the pathophysiology of a STEMI
ACS pathophysiology +:
- thrombus fully occludes the vessel and involves the full thickness of the ventricular wall
- results in an imbalance between O2 supply and demmand to the myocardial cells
- ischaemia
- cell injury/death
Discuss the management of a STEMI
- Code STEMI
- Drugs (Aspirin, anti-platelet, heparin)
- PCI (percutaneous coronary intervention - cath lab) <60 mins
- Throbolysis should be considered if PCI unavailable
- CABGS
Describe how to differentiate between cardiac pain and non-cardiac pain
- nature
- location
- radiation
- precipitating/relieving factors
- Assoc clinical manifestations
Describe conditions that cause ischaemic cardiac chest pain and non-ischaemic cardiac chest pain
Ischaemic cardiac chest pain (angina)
- CAD (atherosclerosis)
- blood clots
- coronary artery spasm
- trauma
- MI
Non-Ischaemic cardiac chest pain
- pericarditis
- myocarditis
- dissecting aortic aneurysm
- atypical ballooning syndrome (takotsudo cardimyopathy)
Outline patient selection criteria for reperfusion therapy
Is the PCI delay time <90mins?
- door to needle (D2N)
- door to balloon (D2B)
- PCI delay = D2B - D2N
List absolute contraindications to thrombolytic therapy
- ischaemic CVA within 3 months
- Intracranial CA
- Aortic dissection
- active bleeding
- head trauma < 3 months ago
Outline four (4) clinical signs which may indicate that reperfusion has been successful
. - ST segment recovery
- QRS vector changes
- re-perfusion arrhythmias
- T wave configuration changes
Briefly outline nursing priorities for a patient undergoing reperfusion therapy
- swift assessment for reperfusion contraindications
- pt education (risk of bleeding, having to stay still)
- swift preparation of pt (large bore IVs, ECG, pedal pulses, checklist)
List the complications that may occur post AMI
- Ischaemic complications (reperfusion failure, angina, infarction, infarction extension)
- Mechanical complications (cardiogenic shock, MV dysfunction, cardiac rupture)
- Throbosis and embolic complications (CNS or peripheral embolisation)
- Chronic complications (pericarditis, depression)
State the clinical indications for recording a right and posterior ECG
Right sided ECG:
- in the case of an inferior AMI (STE in II,III,aVF)
Posterior ECG
- STD in V1-3
Specify where you will place the V leads to record a right and posterior ECG
Right:
V1-6 are placed in a mirror image fashion from standard precordial leads
Posterior:
V4-6 are moved to the posterior of the L chest in lead V7-9 positions
Describe the clinical implications of a pathological Q wave
Pathological Q waves may indicate:
- MI
- Cardiomyopathies
- Rotation of the heart
- Incorrect lead placement
