Ischemia (Acute Coronary Syndromes and stable angina ) Flashcards
What is the most common cause of Acute Coronary Syndromes?
a thrombus from an atherosclerotic plaque blocking a coronary artery. lead to decrease oxygen supply and increase oxygen supply.
What is the common mechanism underlying all Acute Coronary Syndromes?
the rupture or erosion of the fibrous cap of a coronary artery plaque.
What happens when the fibrous cap of a coronary artery plaque ruptures or erodes?
it leads to platelet aggregation and adhesion.
What are the consequences of platelet aggregation and adhesion in Acute Coronary Syndromes?
Platelet aggregation and adhesion in Acute Coronary Syndromes result in localized thrombosis, vasoconstriction, and distal thrombus embolization.
How does thrombus formation and vasoconstriction contribute to myocardial ischemia?
reduce coronary blood flow, leading to myocardial ischemia.
What is the difference between unstable angina, NSTEMI, and STEMI?
- Unstable angina is characterized by subtotal occlusion, supply-led ischemia without infarction, and a high (50%) risk of myocardial infarction (MI) in the subsequent 30 days.
- NSTEMI is also characterized by subtotal occlusion about 90% and infraction if lefted untreated for 30 min .
- STEMI is characterized by complete occlusion thus immediate infraction.
What are the four types of MI, and what distinguishes them?
Type 1: Traditional MI due to an acute coronary event.
Type 2: Ischemia secondary to increased demand or reduced supply of oxygen.
Type 3: Sudden cardiac death or cardiac arrest suggestive of an ischemic event.
Type 4: MI associated with PCI (percutaneous coronary intervention), coronary stenting, or CABG (coronary artery bypass grafting).
What are the symptoms commonly associated with severe crushing central chest pain at rest?
- Pain that radiates to the jaw and arms, similar to angina but more prolonged and
- not relieved by GTN (glyceryl trinitrate).
- They are also associated with sweating, nausea, and often vomiting.
- The duration of pain is typically 30 minutes or longer.
Which groups of individuals are at higher risk of atypical presentation or silent MI?
Answer: the elderly, and patients with diabetes are at higher risk of atypical presentation or silent MI.
What are the possible symptoms of atypical or silent MI?
milder symptoms (without chest pain), especially in younger women, such as shortness of breath, fatigue, body aches, and an overall feeling of illness.
Other symptoms may include an unusual feeling or mild discomfort in the back, chest, arm, neck, or jaw (without chest pain), heartburn, nausea/vomiting, abdominal pain.
- It is important to note that these symptoms may occur up to a month before the occurrence of an MI and can include fatigue, sleep disturbance, shortness of breath, anxiety, indigestion, and palpitations.
What is the significance of xanthelasma as a sign?
Answer:
* Xanthelasma is a sign of atherosclerosis.
- It is a yellowish deposit of cholesterol that forms on the eyelids and is associated with the presence of atherosclerotic plaques.
What are the ECG changes observed in STEMI?
Answer: include
- ST segment elevation in leads consistent with an area of ischemia.
- A new Left Bundle Branch Block (LBBB) can also diagnose a STEMI.
What are the ECG changes observed in NSTEMI?
Answer:
* may be normal or may show ST segment
depression in a specific region,
- deep T-wave inversion, and
- pathological Q waves suggesting a deep infarct (a late sign).
What are the possible ECG findings in unstable angina?
Answer:
* may be normal or may include non-specific changes,
* abnormal T waves, or
* ST depression.
What ECG findings indicate a posterior myocardial infarction (MI)?
Answer:
ST depression with tall R waves in V2-V3 indicates a posterior MI and
* elevation in V7 -V9
What ECG findings suggest an anterior MI?
Answer: include ST segment elevation in the leads corresponding to the anterior region of the heart (typically leads V2-V4).
- Effecting the left anterior decending artery
What are the initial management strategies for unblocking the artery in Acute Coronary Syndromes?
Answer: The initial management strategies include administering
* morphine (with metoclopramide),
* providing oxygen if hypoxic,
* using nitrates if the patient is hypertensive or in acute left ventricular failure (LVF),
* administering aspirin, and
* prescribing ticagrelor or clopidogrel.
What is the definitive management approach for STEMI?
Answer:
* percutaneous coronary intervention (PCI) if available within 2 hours of pain onset.
* If PCI is not available within 2 hours, thrombolysis can be considered.
What is the definitive management approach for NSTEMI?
Answer: involves risk stratification based on ECG changes, troponin levels, and past medical history.
* All patients receive continuing aspirin and fondaparinux (anticoagulant).
* High-risk patients may undergo PCI and receive tirofiban (antiplatelet),
* while low-risk patients may be discharged after repeat negative troponin and followed up.
What are the lifestyle modifications recommended for secondary prevention in Acute Coronary Syndromes?
Answer: The lifestyle modifications include
* participating in a cardiac rehab program,
* making dietary modifications,
* increasing exercise, and quitting smoking.
* It is also important to have good control of blood pressure, cholesterol, and diabetes.
What medications are part of the secondary prevention regimen for Acute Coronary Syndromes (DABS)?
Answer: The medications for secondary prevention are:
* Dual antiplatelet therapy with aspirin for life and 6-12 months of a P2Y12 inhibitor (e.g., ticagrelor).
* ACE inhibitor (ACEi).
* β-blocker, which should be started within 24 hours of confirmed ACS.
* Statin.
Other medications include
* GTN for angina symptoms and
* aldosterone antagonists for patients with symptoms and/or signs of heart failure and left ventricular systolic dysfunction.
In which patient populations does CABG (coronary artery bypass grafting) have a survival advantage over PCI (percutaneous coronary intervention)?
Answer: CABG has a survival advantage over PCI in patients who areover 65 years old, have diabetes, or
have complex 3 vessel disease.
What is the conduit of choice for the left anterior descending coronary artery in CABG?
Answer: The left internal mammary artery
What are some arrhythmias that can occur as complications of Acute Coronary Syndromes?
Answer: include bradycardia, heart block, and tachyarrhythmias such as ventricular fibrillation.
What are some structural complications that can occur after an MI?
Answer: include
* SUdden cardiac death (SCD)
* ventricular septal defect (VSD),
* mitral regurgitation,
* ventricular wall rupture leading to cardiac tamponade (typically occurring 5-10 days post-MI), and
* the formation of a left ventricular mural thrombus that may result in systemic emboli.
What is Dressler’s syndrome?
Answer:
* Dressler’s syndrome is pericarditis that usually occurs around 2-3 weeks after an MI.
- It is characterized by localized immune response causing pericarditis.
What are the types of functional damage that can occur as complications of Acute Coronary Syndromes? 3
Answer: include
- acute ventricular failure (left, right, or both),
- chronic cardiac failure, and
- cardiogenic shock.
Why are anti-platelet medications like aspirin, clopidogrel, and ticagrelor the mainstay of treatment for Acute Coronary Syndrome?
Answer:
* ACS is usually caused by a thrombus from an atherosclerotic plaque blocking a coronary artery.
- When a thrombus forms in a fast-flowing artery, it is predominantly composed of platelets.
- Anti-platelet medications help prevent platelet aggregation and clot formation, reducing the risk of further blockage in the coronary arteries.
Which coronary artery supplies the right atrium, right ventricle, inferior aspect of the left ventricle, and posterior septal area?
Answer:
The Right Coronary Artery (RCA)
supplies the right atrium, right ventricle, inferior aspect of the left ventricle, and posterior septal area.
Which coronary artery supplies the left atrium and the posterior aspect of the left ventricle?
Answer: The Circumflex Artery
supplies the left atrium and the posterior aspect of the left ventricle.
Which coronary artery travels down the middle of the heart and supplies the anterior aspect of the left ventricle and the anterior aspect of the septum?
Answer:
The Left Anterior Descending (LAD)
artery travels down the middle of the heart and supplies the anterior aspect of the left ventricle and the anterior aspect of the septum.
How is NSTEMI diagnosed based on troponin levels and ECG changes?
Answer: NSTEMI is diagnosed when there are raised troponin levels and other ECG changes such as ST depression, T wave inversion, or pathological Q waves.
What is a “silent MI” and who is more likely to experience it?
Answer:
- A “silent MI” refers to a myocardial infarction (MI) that occurs without typical chest pain symptoms.
- Diabetic patients are more likely to experience a silent MI.
Which leads on the ECG correspond to different heart areas supplied by specific coronary arteries?
Answer:
* The leads I, aVL, V3-6 correspond to the anterolateral heart area supplied by the left coronary artery.
* The leads V1-4 correspond to the anterior heart area supplied by the left anterior descending (LAD) artery.
* The leads II, III, aVF correspond to the inferior heart area supplied by the right coronary artery.
What are some alternative causes of raised troponins, other than acute coronary syndrome?
Answer: include
* chronic renal failure,
* sepsis,
* myocarditis,
* aortic dissection, and
* pulmonary embolism.
What is the purpose of percutaneous coronary intervention (PCI) also called coronary angioplasty?
Answer:
- PCI is a procedure that involves inserting a catheter into the patient’s brachial or femoral artery and guiding it to the coronary arteries using X-ray guidance.
- It is used to identify and treat blockages in the arteries by widening the gap with balloons or using devices to remove or aspirate the blockage.
- Stents are often placed to keep the artery open.
What is the BATMAN mnemonic for acute NSTEMI treatment?
Answer: BATMAN stands for:
1. Beta-blockers,
2. Aspirin (300mg stat dose),
3. Ticagrelor (180mg stat dose),
4. Morphine (titrated to control pain),
5. Anticoagulant (Fondaparinux unless high bleeding risk), and
6. Nitrates (e.g., GTN) to relieve coronary artery spasm.
How is the GRACE score used in NSTEMI?
Answer: The GRACE score is used to assess the risk of death or repeat MI within 6 months after an NSTEMI.
- Patients with a medium or high risk score are considered for early PCI within 4 days of admission to treat underlying coronary artery disease.
Q: What is the recommended daily dose of aspirin for secondary prevention in patients post-MI?
A: The recommended dose is 75mg once daily.
Besides aspirin, what are some other antiplatelet options for secondary prevention in MI patients?
A: Clopidogrel or ticagrelor can be used as additional antiplatelet medications for up to 12 months.
Q: What is the recommended dose of atorvastatin for secondary prevention in MI patients?
A: The recommended dose is 80mg once daily.
Q: Which class of medications, such as ramipril, is recommended for ACE inhibition in secondary prevention of MI?
A: are recommended for secondary prevention, and the dose should be titrated as tolerated up to 10mg once daily.