Ischaemic Heart Disease Flashcards
Where are the possible origins of chest pain?
Lungs and pleura
GI system; oesophagus, stomach, gall bladder
Chest wall
CVS- heart and great vessels
What can cause chest pain originating from the lungs and pleura?
Pneumonia
Pulmonary embolism
Pneumothorax
What can cause chest pain originating from the oesophagus?
Reflux
What can cause chest pain originating from the stomach?
Peptic ulcer disease
What can cause chest pain originating from the gall bladder?
Biliary colic
Cholecystitis
What components of the chest wall can cause chest pain?
Ribs
Muscles
Skin
What can cause chest pain originating from the ribs?
Fractures
Bone metastases
What aspects of the CVS can cause chest pain?
Myocardium
Pericardium
Aorta
What can cause chest pain originating from the myocardium?
Angina
MI
What can cause chest pain originating from the pericardium?
Pericarditis
What can cause chest pain originating from the aorta?
Aortic dissection
What kind of risk factors are there for coronary atheroma?
Modifiable and non-modifiable
What are the non-modifiable risks for coronary atheroma?
Increasing age
Male gender (females catch up after menopause)
Family history
What are the modifiable risk factors for coronary atheroma?
Hyperlipidaemia Smoking Hypertension Diabetes mellitus Exercise Obesity Stress
What are the most important risk for coronary atheroma?
Hyperlipidaemia
Smoking
Hypertension
Diabetes mellitus
What does coronary atheroma lead to?
Ischaemic heart disease
By how much does diabetes mellitus increase the risk of ischaemic heart disease?
Doubles it
What is the nature of ischaemic chest pain?
Central, retrosternal, or left sided
Pain may radiate to shoulders and arms, with the left side more common than right, along with the neck, jaw, epigastrum and back
Can ischaemia present with pain in other areas, but not the chest?
No
How is ischaemic chest pain described as?
Tightening, heavy, crushing, constricting and pressure
Occasionally, the pain is described as a burning epigastric pain
When is ischaemic chest pain particularly described as burning epigastric pain?
In an inferior MI
How does ischaemic chest pain vary?
In intensity, duration, onset, precipitating, aggravating and relieving factors
Do the symptoms associated with ischaemic chest pain vary?
Yes
What happens to the symptoms of ischaemic chest pain?
They get progressively worse, from stable angina to unstable angina, to MI
When does angina occur?
When a plaque occludes more than 70% of the lumen
How does stable angina develop?
Atheromatous plaques, with a necrotic centre and fibrous cap, build up in the coronary vessels, leaving less space for the passage of blood. This leads to ischaemia of the myocardium
Describe the chest pain in stable angina
Typical ischaemic chest pain in brief episodes, brought on by exertion, emotion, particularly after meals and in cold weather
What is the chest pain in stable angina described as?
Mild to moderate pain
How are acute episodes of angina treated?
Sub-lingual nitrate spray/tablet
How are episodes of angina prevented?
ß-blockers
Ca channel blockers
Oral nitrates
How are cardiac events prevented when a patient has angina?
Aspirin
Statins
ACE inhibitors
What are the long term treatments for angina?
Consider revascularisation
What causes the worsening of angina?
Progression of the formation of the ateromatous plaque
What happens as angina worsens?
It progresses from stable to unstable angina
Why does the progression from stable to unstable angina occur?
Due to increases occlusion of the lumen
What is unstable angina classified as?
Ischaemic chest pain that occurs at rest (or with minimal exertion)
How is unstable angina chest pain described?
Severe pain
Occurring with a crescendo pattern
What is meant by a crescendo pattern?
Distinctly more severe, prolonged, or frequent than before
What is a myocardial infarction?
The complete occlusion of a coronary vessels, leading to an infarct (death) of the myocardium it supplies
What can cause a myocardial infarction?
The fibrous cap of the atheromatous plaque can undergo erosion or fissuring, exposing blood to the thombogenic material in the necrotic core. The platelet ‘clot’ is followed by a fibrin thrombus, which can either occlude the entire vessel where it forms, or break off the form an embolism
How does MI present?
With typical ischaemic chest pain that is very severe, persistent at rest, and often with no precipitant. It is not relieved by rest or nitrate spray.
Patient may also be breathless, faint, having a ‘feeling of impending death’, an will have autonomic features present
Why may an MI patient feel faint?
Due to LV dysfunction
What autonomic features will a MI patient present?
Sweating
Pallor
Nausea
Vomiting
What is a NSTEMI?
A non ST elevated myocardial infarction
What is a STEMI?
A ST elevated myocardial infarction
What is the pathological difference between NSTEMI and STEMI?
With a STEMI, the infarct is the full thickness of the myocardium, but with a NSTEMI, it’s not.
What is the clinical diagnosis of angina based on?
History
What are the specific signs of angina on examination
None
What may a patient with angina show signs related to on examination?
Risk factors
LV dysfunction
Evidence of atheroma elsewhere
What risk factors of atheroma might be present on examination?
Elevated BP
Corneal arcus
What evidence of atheroma elsewhere could be found?
Signs of peripheral vascular disease
What will the ECG of someone with angina show?
Resting ECG usually normal, but may show signs of previous MI
What are the signs of a previous MI on an ECG?
Pathological Q wave
How is angina confirmed and the severity assessed?
An exercise stress test is undertaken
What happens in an exercise stress test?
Graded exercise on a treatment connected to an ECG until one of the following happens- Target heart rate reached Chest pain ECG changes Other problems
What other problems may stop an exercise stress test?
Arrythmias, low BP etc
What is a positive exercise stress test?
When the ECG shows ST depressions of >1mm
What does a strong positive exercise stress test indicate?
Critical stenosis
What does acute coronary syndrome (ACS) relate to?
A group of symptoms attributed to the obstruction of the coronary arteries
What is ACS a result of?
Unstable angina
NSTEMI
STEMI
What is the priority when diagnosing ACS?
Splitting them into two groups, as the treatment is different
Is the occlusion by a thrombus in unstable angina?
No
Is there an occlusion by a thrombus with NSTEMI?
Partial
Is there occlusion by a thrombus in STEMI?
Total
Is there myocardial necrosis in unstable angina?
No
Is there myocardial necrosis in NSTEMI?
Some
Is there myocardial necrosis in STEMI?
Large myocardial infarct
What is shown on the ECG with unstable angina?
May have ST segment depression, T wave inversion or normal
What is shown on the ECG with NSTEMI?
No ST segment elevation
What is shown on the ECG with STEMI?
ST segment elevation in 2 or more leads facing the same area
1mm in limb leads
2mm in chest leads
New left bundle branch block
What is the biochemical maker in the blood for unstable angina?
None
What is the biochemical maker in the blood for NSTEMI?
Troponin
What is the biochemical marker in the blood for STEMI?
Troponin
How is an ECG used to differentiate between ACSs?
Initial ECG to differentiate STEMI from NSTEMI/unstable angina
What happens to the ECG over time in an MI?
It undergoes several changes over the course of the MI
In minutes to hours, there will be ST elevation and the T wave will be upright
In hours to half a day, there will be ST elevation, decreased T and R wave, and the Q wave begins
Days 1-2, the Q wave will be deeper
Days later, the ST normalises, T wave is inverted and the Q wave persists
Weeks later, the ST and T are normal, but the Q wave persists
How can previous MIs be identified?
Via the persistence of the pathological, deepened Q wave
How can the site of an MI be localised?
Using an ECG
Why can an ECG be used to localise the site of an MI?
As abnormalities will be seen due to the infarcted, dead myocardium
How does an ECG localise the site of an MI?
Look at which lead the abnormality is on, and where that leads view is
What leads will be affected if there is an inferior infarction in an MI?
II, III, aVF
What artery is involved in an inferior MI?
Right coronary
What leads will be affected in an anteroseptal MI?
V1-V2
What artery is involved in an anteroseptal MI?
Left anterior descending
What leads will be affected in an anteroapical MI?
V3-V4
What artery is involved in an anteroapical MI?
LAD (distal)
What leads will be affected in an anterolateral MI?
I, aVL, V5-V6
What artery is involved in a anterolateral MI?
Circumflex
What leads will be affected in an extensive anterior MI?
I, aVL, V2-V6
What artery is involved in an extensive anterior MI?
Proximal LCA
What leads will be affected in a true posterior MI?
Tall R wave in V1
What artery is involved in a true posterior MI?
RCA
What are the cardiac biomarkers?
Troponin
Cardiac enzymes
What can cardiac biomarkers be used for?
Diagnosis of MI
Distinguishing between NSTEMI and unstable angina
What are the cardiac troponins?
Cardiac troponin I (cTnI) Troponin T (cTnT)
What are the cardiac troponins?
Proteins important in actin/myosin interactions
When are cardiac troponins released?
In myocyte death
What is the advantage of cardiac tropnins?
It is a very sensitive and specific marker for MI
Describe what happens to cardiac troponin levels after an MI?
It rises 3-4 hours after the first onset on pain
Peaks at 18-36 hours
Will then decline slowly for up to 10-14 days
How many iso-enzymes of creatine kinase (CK) are there?
3
Where are the isoenzymes of CK found?
Heart, muscle, brain
What is the cardiac isoenzyme of CK?
CK-MB
Describe what happens to CK-MB levels after a MI?
It rises 3-8 hours after onset
Peaks at 24 hours
Levels return to normal in 48-72hrs
How can CK-MB and cardiac troponins be used to distinguish between unstable angina and NSTEMI?
The presence of either of these enzymes means that there has been death of the myocardium, which only happens in NSTEMI, as there is no tissue death in unstable angina
What is the goal in unstable angina treatment?
Prevent it from progressing to MI and limiting muscle loss in MI
How is the progression of unstable angina to thrombosis prevented?
Antithrombotic therapy
What is given in antithrombotic therapy?
Anti-platelet agents
Anticoagulants
Give an example of an anti-platelet agent
Aspirin
Give an example of an anticoagulant
Hepatin
How is perfusion restored in partially occluded vessels when there is a high risk of MI?
Early percutaneous coronary intervation (angioplasty)
Coronary artery bypass graft
What is perfusion restored in partially occluded vessels when there is a low risk of MI?
Initally medical treatment
What is the general treatment used to restore perfusion of partially occluded vessels/
Pain control Oxygen Organic nitrates ß-blockers Statins ACE-inhibitors
What are the surgical treatments in coronary artery disease?
Angiography
Percutaenous coronary artery intervention (PCI)
Coronary bypass grafting (CGPG)
What can angiography be used to do?
View any vessel occlusions, and from the findings choices can be made about the revascularisation surgeries
What does PCI involve?
Angioplasty and stenting
What happens in stenting?
Inflation of a ballon inside the occluded vessel expands a mesh that holds the vessel open, increasing the lumen size and allowing for more blood flow
What does CBPG involve?
Taking an artery from elsewhere in the body and grafting it to the heart
What vessels might be used for CBPG?
Internal mammary artery
Radial artery
Saphenous vein (reversed because of valves)
What are the causes of acute pericarditis?
Infections (viral, TB) 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 leading forward
