Ischaemic Heart Failure Flashcards
What are the 3 types of IHD?
- Unstable angina pectoris
- Non-ST elevated Myocardial infarction
- ST elevated myocardial infarction
What is acute coronary syndrome?
It is myocardial ischaemia or infarction caused by occlusion of the coronary arteries
What are the causes of decreased perfusion to myocardial tissue?
- thrombus(most common cause atherosclerosis)
- embolus
- spasm
- trauma
- congenital
- syphillis
What causes decreased supply of oxygen to the heart?
- Anaemia
- Hypotension
- Cyanotic conditions
What causes increased demand fro the heart?
- thyrotoxicosis
- pregnancy
- hypertension
- aortic stenosis
What is the pathophysiology of Ischaemic Heart disease?
- there is first a stable atherosclerotic plaque
- this has a fibrous cap over the lipid filled lesion
- There are inflammatory enzymes like macrophages that release proteins that cause rupture of the fibrous cap and exposes the thrombogenic lipid core whic forms a thrombus
What is partial coronary artery occlusion?
Common in unstable angina and NSTEMI and is because of the decreased myocardial blood flow that causes myocardial ischaemia particularly in the subendocardial tissue
What is complete coronary artery occlusion?
It is common in STEMI’s this is where there is a transmural infarction
Describe unstable angina?
-This presents as not severe enough to cause ECG changes as well as biochemical markers
Describe NSTEMI?
-This presents as myocardial injury that is severe enough to cause ECG changes and biochemical markers
Describe STEMI?
Myocardial infarction severe enough to cause ST changes and biochemical markers
What are the ECG findings you find in NSTEMI?
-no changes or ST depression with loss of the R wave or T wave inversion
What are the ECG findings you find in STEMI?
-ST elevation in two contigious leads and Left bundle branch block
What are the imitators of NSTEMI?
- infection with fever
- Anemia with Hb<10
- uncontrolled heart failure
- increased exercise and activity
- increased emotional stress
- hyperthyroidism
- vasoconstriction
What is the clinical features of NSTEMI and unstable angina?
- crescendo angina(severe, persistent angina)
- Angina at rest
- Autonomic dysfunction-syncope, diaphoresis, nausea and vomiting
What are the different iso-enzymes of creatinine kinase?
- BB-brain and kidney
- MB- skeletal muscle and heart muscle
- MM-heart muscle
What is are the causes of false positives of troponin t?
- myocarditis/pericarditis
- stroke
- acute renal failure
- burns >30%
- chemotherapy
When does troponin T peak?
12-24 hours
When does Troponin normalise?
7-10 days
What are the biochemical markers we use in ACS?
- troponin T/I
- myoglobin but not used regularly
- CK-MB which is more specific than total creatinine which can also be helpful in determining reinfarcts because of the short half life
What is the management of NSTEMI/unstable angina?
- Admit the patient in ICU
- Start the patient on:
- dual antiplatelet therapy: aspirin and clopidogrel for a minimum of 6 months
- salicylates
- Beta blockers(atenolol) aim to get the HR <70bpm
- statin to keep the LDL <2,5
- Intravenous heparin or low molecular weight heparin subcutaneoulsy
- Nitroglycerin
- ACE inhibitors
- glycoprotein IIb/IIIa receptor antagonists
- Clexane