Acute coronary syndromes Flashcards
Definition of ischemia
A condition in which blood flow is restricted or reduced in certain parts the body. Meaning o2 is flow is reduced
What is cardiac ischemia
The reduction in the flow of o2 to the cardiac muscles
How would u calculate the heart rate of someone with a regular heart rate using an ECG
Count the number of squares in one R-R interval, then divide 300 by this number.
R-R interval = from one QRS complex to another
How would u calculate the heart rate of someone without a regular heart rate using an ECG
Count the number of qrs complexes in a full rhythm strip then times that by 6.
One rhythm strip is 10 seconds or 50 squares
What are thre two types of cardiac arrhythmia
1) regularly irregular, there is a pattern to the irregularity of the heart rate
2) irregularly irregular, there is no pattern to the irregular heart rate
What is a p wave on an ECG
It shows atrial depolarisation,
What is the normal duration of a p wave
120-200 ms and that is 3-5 small squares
What does a long PR interval suggest
atrioventricular delay/ block
What is the QRS complex
It shows ventricular depolarisation
What is the st segment
It shows the amount of time between ventricular depolarisation and ventricular repolarisation
What are the types of acute cardiac ischaemic states
1) unstable angina
2) NSTEMI, non ST segment elevation myocardial infarction
3) STEMI, ST segment elevated myocardial infarction
What is NSTEMI
Non st segment elevated myocardial infarction, this is a heart attack where the ST segment of the ECG is elevated. It is caused by partial occlusion of the coronary arteries of plaque, then when a plaque ruptures ( plaque breaks) this cause caused blood clots to form resulting in thrombosis.
What is unstable angina
This is where plaque/ thrombosis in coronary arteries cause reduced blood flow.
- However, unlike normal angina, the frequency and the severity of the chest pain is higher
- the chest pain also happens at rest
What is atherosclerosis
Thickening or hardening of the arteries caused by a build up of plaque ( cholesterol)
What is STEMI
St elevated myocardial infarction, a heart attack where the st segment on the ECG is elevated, this is caused by a total occlusion of the coronary arteries, unstable plaque rupture occurs causing thrombosis
What is atherosclerosis CAD
atherosclerosis In the coronary arteries which reduces the flow of oxygenated blood going to the heart muscles.
What is thrombosis
A blood clot in blood vessels that reduces the flow of blood.
What is acute myocardial infarction
When the muscles of the heart die caused by sustained myocardial ischemia
How long does it take for a cardiac tissue to die after complete occultation
20-40 minutes
And severe necrosis occurs after 2-3 hours
What are clinical feature of acute MI
- Chest pain for more than 20 minutes
- often associated with nausea, sweating, dyspnea (difficulty breathing)
ECG changes - inverted t wave
- st segment elevation
- q wave development
Enzymatic changes - heart releases troponin
Serum levels increase within 3- 12 hours hours and peak within 24 - 48 hours and return to baseline level in 5-14 days
What is the criteria for a acute MI diagnosis
- ischemia symptoms
- changes to their ECG, st segment/ t wave changes
- rise/fall of serum biomarkers relative to the time of the MI episode
- loss of myocardium on imaging
What are non modifiable risk factors of acute MI
- age
- gender
- family history of IHD
What are modifiable risks factors of acute MI
- drinking
- smoking
- hypertension
- hyperlipidemia
- obesity
- obesity
- sedentary lifestyle
What is myocardial salvage in the acute phase.
- reduce myocardial oxygen demand via
- beta blockers
- nitrates
- restore myocardial blood supply through reperfusion
What is secondary MI treatment
A combination of pharmacological and non pharmacological treatment
What is are the secondary treatment of MI
Pharmacological treatments
S - statin
A - ACE inhibitor
A - dual anti-platelet
B - beta blocker
GTN - glycerine trinitrate, a vasodilator
Non pharmacological treatment:
Cardiac therapy
What lifestyle changes occur after MI
- diet change
- alcohol consumption
- smoking cessation
- weight management
