CVS Ischaemic heart disease Flashcards
What are the causes of chest pain?
Lungs and pleura: pneumonia, pulmonary embolism
GI system: acid reflux, peptic ulcer disease, gall bladder
Chest wall: rib fractures, muscles, skin
CVS: Angina, MI, pericarditis, aortic dissection
What are the risk factors for coronary atheroma?
Non modifiable:
Age, male, family history
Modifiable:
Hyperlipidaemia, smoking, diabetes mellitus, hypertension
What is the location and character of ischaemic chest pain?
Central, restrosternal or left sided. Can radiate to shoulders, arms (mainly left) and jaw.
The pain is described as heavy and tightening
What is the difference between stable and unstable angina?
Stable angina is mild-moderate ischaemic pain bought on by exertion but is relieved by rest.
Unstable angina is ischaemic pain that occurs at rest or very little exertion. It is a severe pain with a crescendo pattern.
How is angina treated?
Acute episodes are treated with a sublingual nitrate spray. Beta blockers and calcium channel blockers are used to prevent episodes.
Long term revascularisation may be considered
What causes an MI wrt the athersclerotic plaque?
The fibrous cap of the plaque undergoes erosion or fissuring exposing blood to the thrombogenic material in the necrotic core. The platelet clot is followed by a fibrin thrombus which occludes the vessel or breaks off to form an embolism.
MI is a severe pain with no relief.
What is the difference between an NSTEMI and STEMI MI?
NSTEMI - non ST elevated MI
The infarct is no the full thickness of the myocardium
STEMI - ST elevated MI
The infarct is the full thickness of the myocardium
What is an exercise stress test?
Uses to confirm angina and assess its severity.
Graded exercise on a treadmill until target HR reached, chest pain, ECG changes or other problems eg low BP
Positive test is ST depressions
What is acute coronary syndrome?
A group of symptoms caused by obstruction of coronary arteries : unstable angina, NSTEMI, STEMI
How can you tell from an ECG that there has been a previous MI?
There is pathological deepened Q wave
What are the chemical biomarkers used for the diagnosis of MI?
Troponins I/T
- proteins important in actin and myosin interaction which are released on myocyte death
- very sensitive and specific
- rise after 3-4hrs, peak at 18-36hrs and decline for 10-14 days
Creatine kinase
- also present in skeletal muscle and brain
- rises after 3-8hrs and peaks at 24hrs, declines for 48-72hrs
These biomarkers are used to distinguish between unstable angina and NSTEMI (no tissue death in unstable angina)
How is unstable angina / MI treated?
Goal is to prevent unstable angina progressing to MI and limiting muscle loss in MI.
Prevent progression of thrombosis: anti-platelet agents eg aspirin and anticoags eg heparin.
Restore perfusion of occluded vessels: PCI (angioplasty and fitting a stent) or a coronary artery bypass graft (usually great saphenous vein or radial artery).
What are the causes and symptoms of acute pericarditis?
Caused by infections, malignant deposits, autoimmune diseases, cardiac surgery
Symptoms are a central/left sided chest pain. It is sharp and worsened on inspiration, but improved by leaning forward.
Which part of the myocardium is most vulnerable to ischaemia?
Flow occurs from epi –> endocardium so subendocardial muscle is most vulnerable to ischaemia
What is the difference between a vulnerable and stable plaque?
A stable plaque has a small necrotic core with a thick fibrous cap so is less likely to fissure/rupture
A vulnerable plaque has a large necrotic core and a thin fibrous plaque so the cap is more likely to fissure/rupture
