Cardiac consequences of atheroma Flashcards
The ‘most important’ consequence of atheroma is
Death (ventricular fibrillation)
Anatomy of atheroma:
- Fibrous cap
2. Soft interior
What makes up soft interior of atheroma?
Lipids Cholesterol WBCs Proteins Calcium
Non-modifiable risk factors for atheroma;
Age
Gender
FHx
Ethnicity
Modifiable risk factors for atheroma:
Smoking Diabetes Obesity Lipids Hypertension Stress, pollution, lack of exercise
Timeline of atheroma
- Fatty streak
- Fibrous cap formation
- Core of lesion becomes necrotic (atheroma)
- Thinning and rupture of cap
- Arterial occlusion
Why is a fibrous cap formed?
Bodies attempt to stabalise things
Why is an atheroma a symptomatic?
Positive remodelling - vessel widens
What occurs when a cap ruptures?
Inflammatory process - platelets adhere - thrombus formed
Stable angina =
Angina on exertion
What is included in acute coronary syndrome?
Unstable angina
Myocardial infarction
How to diagnose stable angina:
- Hx
- Examination (often normal)
- Stress testing
3 types of stress testing:
- Exercise ECG
- Stress echo
- Myocardial perfusion scan
What would happen on an exercise ECG with stable angina?
Normal = normal ECG Exercise = ST depression
What type of imaging is an echo?
Ultrasound
What happens in a stress echo with angina?
Part of heart supplied will increased contractility, part of heart with narrowing won’t contract as well
What happens in a myocardial perfusion scan?
Inject isotope - shows perfusion. Take images at rest and during exercise.
How to diagnose MI:
History
ECG
Enzymes
Most common blocked arteries in MI:
- Left anterior descending
- Right coronary artery
- Left circumflex
Left anterior descending supplies:
Anterior wall
LV septum
Right coronary artery supplies:
Inferior/posterior wall
LV septum
Left circumflex supplies:
Lateral wall of LV
Subendothelial MI:
NSTEMI
Transmural MI
STEMI
In a normal ECG, what is Q =
First downward line after P
In a normal ECG, what is R =
First upward line after P
In a normal ECG, what is S =
First downward line after R
What part of the ECG do we look at in an MI?
ST segment
Name the ‘12 leads’ on an ECG?
avR avL avF I II III V1-V6
Leads for left anterior descending (anterior) =
V1-V6
Leads for right coronary artery (inferior)
II, III, avF
Leads for circumflex artery (lateral)
I, avL, V5, V6
Enzymes to check for makers of MI:
CK-MB
Troponin I
Troponin T
Myoglobin
Most sensitive markers of MI
Troponin
Troponin is sensitive but not
Specific
What else may increase troponin?
hypertension septicaemia PE subarachnoid haemorrhage AF
What makes up the troponin complex?
Troponin C: ca2+
Troponin I: inhibitory
Troponin T: tropomyosin binding
To diagnose MI, what has to happen to troponin?
Rise and/or fall in troponin level measured a few hours apart (need multiple blood tests)
Complications of MI: 0-24 hrs
Arrhythmia
Cardiac death
Cardiogenic shock
Complications of MI: 1-3 days
Pericarditis
Complications of MI: up to 2 weeks
Myocardial rupture
Complications of MI 3 weeks +
Heart failure
What can occur if myocardial rupture is incomplete
False aneurysm
What would a patient present with with interventricular septum rupture:
Hypotension
Loud murmur
Very ill
Papillary muscle most likely to break:
Posteriomedial
Heart failure symptoms:
SOB Peripheral oedema Orthopnoea PND fatigue
What can happen with a left ventricular aneurysm:
Arrythmias
Thrombus formation
Sudden cardiac death can occur in what MI?
STEMI
Treatment for NSTEMI:
Anti-platelets
LWMH
Statin
Anti-ischemic
Examples of anti-ischemic
Beta-blockers
Nitrates
Treatment for STEMI:
Quick reperfusion:
- Fibrinolysis
- Angioplasty
- Percutaneous coronary intervention
