Acute Coronary Disease Flashcards
Define ACD
Any sudden cardiac event suspected or proven to be related to a problem with the coronary arteries.
The problems associated with ACD are due to myocardial ischaemia
What is this?
reduced blood flow and hence O2 to the myocardium through the coronary arteries.
Describe a major MI
due to a complete coronary artery occlusion (STEMI) which causes full thickness damage to the myocardium.
- ST elevation MI = STEMI
- Q wave MI - if left untreated at 3 days
- Transmural MI
Describe a minor MI
due to a partial coronary occlusion (NSTEMI) which causes partial thickness damage just under the endocardium.
- non ST elevation = NSTEMI
- no Q wave
- subendocardial MI
What is the difference between chronic coronary disease and acute coronary disease?
Chronic - has a thick fibrous cap so the plaque is less likely to rupture (stable angina)
Acute - has a thin fibrous cap so is more likely to rupture and therefore cause a thrombosis. (unstable angina)
How would you be able to detect cardiac cell death?
-positive cardiac biomarkers (blood test- troponin)
- symptoms of ischaemia (SOB, chest pain)
- new ECG changes
- evidence of coronary problem on coronary angiogram or autopsy
- evidence of new cardiac damage on another test
Other than the breakdown of myocardium, what are the other ways that troponin can increase in the blood?
Pulmonary embolism
Sepsis
Renal failure
Sub arachnoid haemorrhage
Describe the five types of MI 1. 2. 3. 4a. 4b. 5.
1. spontaneous ischaemia associated with plaque rupture/erosion/fissuring causes: -atheroscelosis -coronary vasospasm (cocaine) -coronary tear (common in young females) -embolism down coronary artery -inflammation of the coronary arteries -radiotherapy causing stenosis and fibrosis
- imbalance of supply and demand of oxygen
- hypertrophy - sudden cardiac death with symptoms of ischaemia accompanied with a ST elevation. (complete occlusion)
4a. associated with percutaneous coronary intervention (stenting) with an increase of three fold of normal troponin levels.
4b. associated with verified stent thrombosis via angiography or autopsy. - Associated with CABG.
On an ECG, which coronary arteries would cause a
lateral MI
anterior MI
inferior MI
Lateral = circumflex artery Anterior = LAD artery Inferior = right coronary artery
A posterior MI can be easily missed as there are no leads on the back of the patient measuring the heart activity.
Posterior wall is usually supplied by the RCA so inferior changes may also be noted.
Can be supplied by LCx
When should leads be put on the posterior of a patient?
If
ECG is normal
patient looks very unwell, sweaty, chest pain
Risk factors for a MI
¥ Male ¥ Age ¥ Known heart disease ¥ High blood pressure ¥ High cholesterol ¥ Diabetes ¥ Smoker ¥ Family history of premature heart disease
What is the treatment for a STEMI?
Reperfusion treatment
- mechanical (PCI) - in a cath lab
- medication (thrombolysis) - dissolves clot, potent blood thinner
What are the contradictions of thrombolysis?
Stroke, previous bleed, recent operations, if on warfarin or aspirin, severe hypertension.
What are the common NSTEMI patients with an elevated troponin level?
¥ older
¥ more likely to have previous MI
¥ more likely to have previous CABG/PCI
¥ may not have clear, obvious presentation
How do you manage a suspected ACS?
admit to hospital
monitor cardiac activity
What are the investigations for suspected MI?
ECG
- STEMI is the most important area
- Q waves are not important while assessing as they don’t show until after a couple of days
Blood test
- troponin
- check if anaemic
- check kidney function, cholesterol
Which two drugs are used to relieve chest pain?
Glycerol trinitrate (GTN)
¥ Vasodilator - opens up coronary arteries
¥ Doesn’t work if arteries are completely blocked already (STEMI patients)
¥ Can give sub-lingual or as intravenous infusion
Opiates (eg morphine)
¥ Helps relieve anxiety too
¥ Also helps venodilate which may have haemodynamic benefits
Which drugs are used to treat MI
Anti platelet
- aspirin
- ticagrelor
Anti thrombotic drugs
-Fondaparinux
Beta blocker (decrease BP by blocking B1 receptors) - Bisoprolol
Statins (reduce production of LDL in liver)
- Simvastatin
ACEI (decrease permeability of conducting duct- decreases BP)
- Ramipril
Risks of coronary angioplasty/ angiography/ stenting
Bleeding Blood vessel damage Myocardial infarction Coronary perforation Stroke Dye can affect kidneys
State some complications of MI
Short term
Long term
Short term: Arrhythmia Mechanical - Cardiogenic shock - Myocardial rupture Valve dysfunction due to papillary muscle dysfunction/rupture Acute Ventricular Septal Defect
Long term:
Higher risk of bleeding as on anti-platelet drugs
Increased risk of further myocardial infarction/death
Cardiac failure
Before being discharged what four things should be done?
¥ Check on correct medications- b blockers, aspirin, statin
¥ Address risk factors
¥ Cardiac rehabilitation
¥ Follow-up plans
