Acute Coronary Syndromes and Sudden Death Flashcards
What is the term for a blood clot formation in the coronary arteries?
Coronary thrombosis
What is the term used to describe the rupture of a plaque in the arterial wall?
Plaque rupture
What type of plaque is considered “vulnerable” due to its thin cap?
Thin cap = ‘vulnerable’ plaque
What components are exposed when a plaque ruptures?
Collagen/lipid
What is the term for the strong tendency of a substance to promote blood clot formation?
Thrombogenic +++
What is the initial step in the formation of a blood clot in coronary thrombosis?
Platelet adhesion
What is the term for a mass of platelets that form at the site of plaque rupture?
Platelet thrombus
What happens to the clotting system when plaque rupture occurs?
Clotting system activated
What type of thrombus is formed as a result of coronary thrombosis?
Red thrombus
What can result from partial or intermittent occlusion of a coronary artery or embolism?
Occlusion (?partial/intermittent) or embolism
What are some diagnostic factors for acute coronary syndrome (ACS)?
History, typical cardiac pain, atypical pain, shortness of breath, collapse, pale, sweaty, complications (e.g., arrhythmia, heart failure), ECG changes (ST elevation/depression, T wave inversion), elevated cardiac markers (cardiac troponin)
Where does cross-bridging between thick and thin filaments occur?
Troponin complex
What does Tn-T bind to in the troponin complex?
Tropomyosin
What does Tn-C bind to during excitation-contraction coupling?
Calcium (Ca2+)
Which components of the troponin complex are specific to cardiac muscle?
Tn-T and Tn-I
What is the role of creatine kinase (CK)?
Moves high-energy phosphate from ATP in the mitochondria to ADP in the cytoplasm
Which form of creatine kinase is more specific to cardiac muscle?
CK-MB
What are some markers used for diagnosing myocardial damage?
Cardiac specific markers (troponin T or I), cardiac selective enzymes (creatine kinase MB), myoglobin, non-specific enzymes (AST, LDH)
What does STEMI stand for, and which region of the heart does it typically affect?
STEMI stands for ST-segment elevation myocardial infarction. It typically affects the anterior region of the heart.
What ECG finding is commonly observed in widespread myocardial ischemia?
ST depression
What does NSTEMI stand for, and which region of the heart does it typically affect?
NSTEMI stands for non-ST-segment elevation myocardial infarction. It can affect the anterior region of the heart.
What are some key components of acute management for acute coronary syndrome (ACS)?
Aspirin, LMW heparin (e.g., enoxaparin), anti-anginal medication, nitrate (e.g., GTN), revascularization (timing may vary).
What is the recommended anti-thrombotic treatment for ACS?
The recommended anti-thrombotic treatment for ACS includes aspirin, P2Y12 inhibitors (such as clopidogrel or ticagrelor), and anticoagulants (such as heparin or low-molecular-weight heparin).
What are some common presentations of acute coronary syndrome (ACS)?
Common presentations of ACS include unstable angina, NSTEMI, and STEMI.
What is the term used to describe the sequence of events that occur during myocardial ischemia?
Ischemic cascade
What factors influence the severity of ischemia?
Time and metabolic disturbance
What type of cardiac dysfunction can occur as a result of ischemia?
Diastolic dysfunction and systolic dysfunction
What are some ECG changes that can be observed during ischemia?
ECG changes such as ST-segment depression or elevation
What is a common symptom experienced during myocardial ischemia?
Chest pain
What is the consequence of prolonged ischemia on myocytes?
Myocyte necrosis
What can result from inadequate blood supply during ischemia?
Hypoperfusion, arrhythmia, acute heart failure
How long does it take for myocardial necrosis to be detectable after the onset of acute ST-segment elevation myocardial infarction (STEMI)?
Necrosis is detectable after 15 minutes.
Which part of the myocardium is more sensitive to ischemia?
Sub-endocardial myocardium
Up to how many hours after coronary occlusion can myocardium be salvaged?
Myocardium can be salvaged up to 12 hours after coronary occlusion.
What is the primary treatment option for acute reperfusion in STEMI?
Thrombolysis with “clot-buster” drugs (fibrinolytic agents).
What was the significant finding of the ISIS-2 trial regarding thrombolysis for acute myocardial infarction (MI)?
The trial showed a 39% reduction in mortality with streptokinase and aspirin compared to placebo.
What is the alternative treatment option for acute reperfusion in STEMI, as shown by the PAMI trial?
Primary percutaneous coronary intervention (PCI)