Acute Coronary Syndrome Flashcards
what is ACS and what are the 3 clinical subtypes of it?
ACS encompass a spectrum of acute myocardial ischaemic states
1- Unstable Angina (UA)
2-Non-ST segment Elevation Myocardial Infarction (NSTEMI)
3-ST-segment Elevation Myocardial Infarction (STEMI)
what is ACS triggered by?
atheromatous plaque disruption (rupture/ fissure/ erosion
which ACS is only partial occlusion of artery?
UA or NSTEMI
which ACS is sustained occlusion of artery?
STEMI
what are the 3 characteristics of unstable Angina?
acceleration in frequency or severity of chest pain
new-onset anginal pain
anginal chest pain that abruptly occurs at rest
which ACS shows enzymatic evidence of cell death
NSTEMI
why is STEMI the most severe?
complete occlusion
ischaemia-induced electrical instability -can inc risk of sudden cardiac death
how long after blood flow stops does cell death in nstemi and stemi cells occur?
20-40 min
2-3 hours =significant death
what are the two phases of acute myocardial infarction?
phase of ischaemia(reversible injury)phase of infarction(irreversible injury)
what are the 4 clinical features of ACS?
Pain & apprehension
Haemodynamic
Serial ECG changes
Serial Cardiac Biomarker changes
What are the ECG changes in STEMI?
ST segment elevation
Pathological Q wave development
what are the ECG changes in NSTEMI?
ST segment depression
T wave inversion
what are the primary in diagnosis of ACS?
Confirm or rule out ACS secondary to obstructive CAD
low risk- UA/NSTEMI
What do elevated, sustained troponin levels indicate?
STEMI
how would you INITIAlLY manage ACS?
Analgesic & anti-ischaemic therapy
what IMMEDIATE treatment would you use for ACS?
medication
asprin/bb/GNT/dimorphine or morphine/ anti-coagulants
what are the main goals in the clinical management of STEMI?
1-establish & maintain patency of the infarct-related artery
2-limit the consequences of myocardial ischaemia
3-enhance myocardial healing & reduce the likelihood of recurrent events
what is the open artery theory?
Prompt and complete restoration of flow in the occluded artery decreases infarct size, preserves left ventricular (LV) function, and improves survival rates
what are the two strategies on the clinical management of STEMI? ( revascularisation/reperfusion)
1- mechanical- PCI
2-Pharmacological- thrombolytic or finbriotic therapy
what are the two treatment pathways of UA and NSTEMI?
1-Initial Conservative Strategy (medical)-low risk
2-Early Invasive Strategy(medical or surgical reperfusion)-high risk
what are the 3 types of agents used in antithrombotic therapy?
1 Thrombolytic / Fibrinolytic agents
2 Antiplatelet agents
3 Anticoagulants
what does the thrombolytic therapy do?
Activation of the endogenous plasminogen fibrinolytic system- breakdown of clot
what are the 2 thrombolytic agents?
1 Streptokinase (SK) 2 Tissue-type plasminogen activators (t-PAs)
is thrombolytic therapy first or second line?
second , PCI FIRST
what are side effects of thrombolytic therapy?
haemorrhage
allergic reactions (SK)
hypotension
reperfusion-induced arrhythmias
what are the 3 types of anti-platelet agents?
1- Cyclooxygenase inhibitors –Aspirin
2- ADP receptor antagonists
3- GPIIb/IIIa receptor antagonists
all decrease platelet aggregation
what is the dose of aspirin?
150-300 mg loading dose; 75-100 mg/day maintenance dose
what is the dose of Clopidogrel?
300-600 mg loading dose; 75 mg/day maintenance dose
what is the dose of Prasugrel?
60 mg loading dose; 10 mg/d maintenance dose
what is the dose of Ticagrelor?
180 mg loading dose; 90 mg bid maintenance dose
what is the MOA of GPIIb/IIIa Receptor Antagonists
they bind to platlet receptors so fibrin cannot
what is the MOA of aspirin?
Irreversible COX Enzyme Inhibitor
what is the MOA of clopidogrel?
Irreversible ADP Receptor Antagonist-Binds to platelet P2Y12 ADP receptor -prevents ADP from binding
what is the MOA of prasugrel?
Irreversible’ GPIIb/IIIa Receptor Antagonist
what is the aim of the aim of anticoagulant therapy?
inhibit coagulation-driven thrombus formation in ACS
inactivate Factor IIa(thrombin) and/or FXa& FIXa
what are the 3 indirect thrombin inhibitors?
UF Heparin –inactivation of thrombin (FIIa), FXa& FIXa
LMW Heparins –inactivation of FXa
Fondaparinux -inactivation of FXa
name the direct thrombin inhibitor?
Bivalirudin- direct inactivation of thrombin (FIIa)
what are the 5 treatments after ACS?
1- aspirin 2- P2Y12 receptor antagonists 3- statins 4-b-blockers 5 angiotensin converting enzyme inhibitors
