Ischaemia and Angina Flashcards
What is ischaemia?
a condition where there is a lack of oxygen and nutrients in tissues due to inadequate blood flow, often leading to cardiovascular disorders such as angina and myocardial infarction (MI).
Causes of ischaemia
- Arteriosclerosis: Stiffening and thickening of blood vessel walls, leading to narrowing and reduced flexibility.
- Atherosclerosis: A type of arteriosclerosis where fatty and fibrous deposits accumulate in the endothelium, often at bends or branches of arteries.
- Thrombosis: Formation of a blood clot (thrombus) that can block vessels, often caused by plaque rupture, platelet activation, and clotting.
Blood supply, oxygen and nutrients to tissues restricted.
What are contributing factors for atherosclerosis and thrombosis?
Endothelial damage (due to lipid abnormalities or surgery)
Abnormal blood flow (e.g., turbulence)
High fibrinogen levels
Certain oral contraceptives
Symptoms associated with atherosclerosis in coronary arteries
Chest pain/pressure (angina)
Symptoms associated with atherosclerosis in brain arteries
Numbness, weakness, slurred speech, facial drooping (TIA or stroke)
Symptoms associated with atheroscelrosis in limb arteries
Pain while walking (peripheral artery disease)
Symptoms associated with atherosclerosis in renal arteries
High blood pressure, kidney failure
What is angina?
Chest pain caused by ischaemia in the ventricles, typically described as severe pain radiating to the left arm, neck, or jaw. It results from factors released during hypoxia stimulating heart receptors.
What is silent angina?
Silent angina refers to ischaemia without pain, which is more common in individuals with diabetes.
What triggers angina?
exercise, emotional stress, cold environments, and heavy meals. Angina pain generally resolves with rest (within ~3 minutes).
Types of angina
- Chronic Stable Angina: Caused by fixed narrowing of coronary arteries. Occurs during exercise, but not at rest.
- Unstable (Crescendo) Angina: Sudden and increasing severity of angina, occurring at rest or minimal exertion, often due to plaque rupture and thrombus formation. Can lead to infarction.
- Variant (Prinzmetal’s) Angina: Caused by coronary artery spasm, typically at rest and often in the morning. ECG shows ST segment changes.
How is angina diagnosed?
1, History: Careful assessment of symptoms and triggers.
2. ECG Findings: ST segment depression (at rest or during exercise).
Limitations: ST segment changes may be influenced by potassium disturbances or certain drugs like digoxin.
What tests are used to rule out a heart attack when diagnosing angina?
Electrocardiogram (ECG)
Coronary angiogram
Echocardiogram
Exercise ECG (stress test)
MRI stress test
Blood tests
What are the first-line drugs for treating stable angina?
Beta blockers or calcium channel blockers are typically the initial choice, selected based on the patient’s comorbidities, contraindications, and preferences.
What is the preferred combination for treating stable angina when symptoms aren’t controlled with monotherapy?
Combine a beta blocker with a dihydropyridine calcium channel blocker (e.g., slow-release nifedipine, amlodipine, or felodipine).
When should a third drug be prescribed for stable angina?
A third drug should be added if symptoms remain uncontrolled with two drugs and the patient is either awaiting revascularisation or revascularisation is not appropriate or acceptable.
Common third-line options include long-acting nitrates, ivabradine, nicorandil, or ranolazine.
What other drugs can be used for angina if beta blockers and calcium channel blockers are not tolerated?
Long-acting nitrates
Ivabradine
Nicorandil
Ranolazine
These drugs improve oxygen supply or reduce oxygen demand on the heart.
What are safety considerations when prescribing ivabradine or nicorandil?
Both drugs have MHRA warnings, so their use should be guided by safety considerations and patient tolerability.
What is the difference between angina and a heart attack?
The symptoms of angina and heart attacks are similar, but angina lasts for a shorter period and improves with rest, while a heart attack lasts longer and requires immediate medical intervention.
What is the role of Omega-3-acid ethyl esters (e.g., Lovaza) in cardiovascular treatment?
Omega-3-acid ethyl esters help to reduce triglyceride levels and improve heart health.
