Lecture 10 - Ischaemic Heart Disease Flashcards
What are causes of chest pain in the lungs and pleura?
Pneumonia
Pulmonary embolism
Pneumothorax
What are causes of chest pain in the GI system?
Oesophagus - reflux
Peptic ulcer disease
Gall bladder - biliary colic, cholecystitis
What are the causes of chest pain in the chest wall?
Ribs
Muscle
Skin
What are the causes of chest pain in the CVS?
Myocardium - angina, MI
Pericardium - pericarditis
Aorta - aortic dissection
What are the 3 non modifiable risks for coronary atheroma?
Increasing age
Male gender
Family history
What are the 8 modifiable risks for coronary atheroma?
Hyperlipidaemia Smoking Hypertension Diabetes mellitus Exercise Obesity Stress
Where is the chest pain from IHD?
Central, retrosternal or left sided.
May radiate to shoulders, arms, neck, jaw, and back.
What sort of pain comes from IHD?
Tightening, heavy, crushing, constricting, pressure.
What sort of pain could come from an inferior MI?
Burning epigastric (like heartburn/indigestion)
How do the symptoms of IHD get progressively worse?
Stable angina –> unstable angina –> MI
What is stable angina?
Atheromatous plaques with necrotic centre and fibrous cap build up in coronary vessels occluding the lumen. Leads to ischaemia of myocardium.
How much of the lumen is occluded in angina?
> 70%
What is the chest pain in stable angina?
Typical ischaemic chest pain.
Brought on in brief episodes by exertion, stress and cold weather.
Mild to moderate.
How are acute episodes of angina treated?
Sub lingual nitrate spray
How are angina episodes prevented?
B blockers, Ca channel blockers, oral nitrates
How are cardiac events prevented in angina?
Aspirin, statins, ACE inhibitors
How is angina treated long term?
Revascularisation
What is unstable angina?
Progression from stable angina due to increased occlusion
What is the chest pain in unstable angina?
Ischaemic chest pain occurring at rest or on minimal exertion.
Severe and occurs with a crescendo pattern.
What is an MI?
Complete occlusion of a coronary vessel leading to an infarct of the myocardium it supplies
What happens in an MI?
The fibrous cap of the plaque is eroded, exposing the blood to the thrombogenic material in the core - platelet clot is followed by a fibrin thrombus to occlude the vessel or break off to form an embolism
What is the chest pain in an MI?
Typical ischaemic chest pain.
Severe and persistent at rest, no relief from rest or nitrate spray.
What are the symptoms of an MI?
Chest pain Breathlessness Faint Anxiety Sweating Pallor Nausea Vomiting
What is an NSTEMI?
Non ST elevated MI
What is the significance of an NSTEMI?
Infarct is not full thickness of myocardium
What is a STEMI?
ST elevated MI
Whar is the significance of a STEMI?
Infarct is full thickness of myocardium
What would the resting ECG show in angina?
Normal
What is the exercise stress test graded on?
Heart rate
Chest pain
ECG changes
Other problems
What is shown in a positive exercise stress test?
ST depression of >1mm
What is acute coronary syndrome?
Group of symptoms attributed to obstruction of coronary arteries
What is acute coronary syndrome a result of?
Unstable angina, STEMI and NSTEMI
What level is the occlusion by thrombus in unstable angina?
Partial
What level is the occlusion by thrombus in NSTEMI?
Partial
What level is the occlusion by thrombus in STEMI?
Total
What level is the myocardial necrosis in unstable angina?
None
What level is the myocardial necrosis in NSTEMI?
Some
What level is the myocardial necrosis in STEMI?
Large myocardial infarct
What is the effect on ECG in unstable angina?
May have ST depression, T wave inversion or normal
What is the effect on ECG in NSTEMI?
No ST elevation
What is the effect on ECG in STEMI?
ST elevation
What is the biochemical marker in the blood in STEMI and NSTEMI?
Troponin
What is the ECG change minutes-hours after an MI?
ST elevation, T wave upright
What is the ECG change hours-day 1/2 after an MI?
ST elevation, decreased T wave, decreased R wave, Q wave begins
What is the ECG change days 1-2 after an MI?
Q wave deeper
What is the ECG change days after an MI?
ST normalises, T wave inverted, Q wave persists
What is the ECG change weeks after an MI?
ST and T normal, Q wave persists
Which ECG leads would show an inferior infarction?
II, III, aVF
Which artery would lead to an inferior infarction?
Right coronary
Which ECG leads would show an antero septal infarction?
V1, V2
Which artery would lead to an antero septal infarction?
Left anterior descending
Which ECG leads would show an antero apical infarction?
V3, V4
Which artery would lead to an antero apical infarction?
Left anterior descending (distal)
Which ECG leads would show an antero lateral infarction?
I, aVL, V5, V6
Which artery would lead to an antero lateral infarction?
Circumflex
Which ECG leads would show an extensive anterior infarction?
I, aVL, V2, V3, V4, V5, V6
Which artery would lead to an extensive anterior infarction?
Proximal left coronary
Which ECG leads would show a true posterior infarction?
Tall R in V1
Which artery would lead to a true posterior infarction?
Right coronary
When do troponin levels rise after an MI?
Rise 3-4 hours after
Peak 18-36 hours
Decline slowly for 10-14 days
When do creatine kinase levels rise after an MI?
Rise 3-8 hours after
Peak 24 hours
Return to normal 48-72 hours after
Specific isoenzyme for myocardium
How are biochemical markers used?
Distinguishes between unstable angina and NSTEMI - no myocardium death in unstable angina
How is unstable angina treated?
Preventing it from progressing to MI by:
Preventing progression of thrombosis
Restoring perfusion of partially occluded vessels
How is the progression of thrombosis prevented?
Anti thrombotic therapy - antiplatelets (aspirin) and anticoagulants (heparin)
How is perfusion restored in partially occluded vessels in high risk patients?
Angioplasty/percutaneous coronary intervention
Coronary artery bypass graft
How is perfusion restored in partially occluded vessels in low risk patients?
Medical treatment
How is perfusion restored in partially occluded vessels in general?
Pain control Oxygen Organic nitrates B blockers Statins ACE inhibitors
How is angioplasty used?
To view any vessel occlusions
How is pecutaneous coronary intervention used?
Angioplasty and stenting - inflation of a balloon inside the vessel expands a mesh to hold the vessel open
How is coronary bypass (CBPG) grafting used?
Take an artery from somewhere else in the body and graft it to the heart
Which vessels can be used for CBPG?
Internal mammary artery
Radial artery
Saphenous vein
What has to be done to the saphenous vein for CBPG?
Reversed because of the valves
What can cause acute pericarditis?
Infection Post MI/cardiac surgery Autoimmune Uraemia (kidney failure) Malignant deposits
What are the symptoms of acute pericarditis?
Central/left sided chest pain
Sharp, worse on inspiration
Improved by leaning forward