Angina
In the heart, the coronary circulation fills blood only during diastole. – Due to atherosclerosis,
these coronary arteries occlude over time, blocking blood flow to the muscles. – This means
that areas of the myocardium become ischemic, causing pain, especially during periods of high
oxygen demand.
– To counter this, the body seeks to increase heart rate and contractile force by increasing
sympathetic nerve stimulation.
– However, this only exacerbates the problem as it further increases O2 demand. – Therefore,
when treating angina, we strive to relax the heart and give more time to meet and reduce the
need for oxygen. There are 2 main types of angina:
Stable:
This is a chronic condition which occurs when >70% of the vessel is occluded. It has 3 main
defining criteria:
i) Constricting discomfort in the front of the chest/neck/shoulders/arms
ii) It is precipitated by physical exertion
iii) Relieved by rest or GTN spray in 5 minutes
– Typical angina has all 3 features, whereas atypical angina gives 2 of these features
Unstable:
This is chest pain that occurs at rest and is treated as part of Acute coronary syndrome
– Usually due to rupture of plaque which leads to incomplete occlusion of coronary artery
– Relieved by nitroglycerin with ST-segment depression
– However, there is high risk of progression to myocardial infarction (treated as ACS)
Diagnosis:
– 1st line is CT coronary angiography
– 2nd line is non-invasive functional imaging to look for reversible myocardial ischaemia
Management:
The management for stable angina involves 3 types of medication:
1) Prophylaxis –> Give Aspirin + Statin
2) Symptom Relief –> Glyceryl trinitrate spray – given to relieve symptoms after 5 minutes
, 3) Medical Therapy –> 1st line B-blocker or Ca2+ channel blocker (Verapamil or Diltiazem)
– If still symptomatic do dual therapy with Beta-Blocker + Dihydropyridine
– If dual therapy not tolerated –> Nicorandil or Ivabradine or Long-acting nitrate
Prinzmetal Angina
Myocardial Infarction
This is a term which means the irreversible death of cardiac myocytes, which occurs due to
ischaemia
– It is due to the rupture of a plaque which leads thrombosis and complete occlusion of the
artery
– It can be divided into an ST-elevated Myocardial infarction (STEMI) and non-elevated
(NSTEMI)
– It is usually seen in older men with vascular risk factors e.g. hypertension, diabetes, smoking
Symptoms:
– Acute crushing central chest pain that comes on rest (maybe no pain in elderly and diabetics)
– Pain radiates to jaw, neck, either/both Upper limb
– Sweaty and clammy
– Nausea, Vomiting and epigastric pain
Tests:
Blood Troponin:
Levels of troponin I indicate damage to myocardial cells. – Two samples taken 3h apart and
indicate possible infarction. – Levels rise 2-4 hours and peak at 24 hours
ECG:
This is helping in identifying ischaemic changes
STEMI = >1mm ST elevation in at least 2 consecutive limb leads
Or >2mm ST elevation in at least 2 consecutive precordial leads
Or new onset left-bundle branch block.
By seeing which leads the ST elevation occurs in, we can determine which artery has been
occluded:
– Lead V1-V4 = anterior territory –> LAD artery
In the heart, the coronary circulation fills blood only during diastole. – Due to atherosclerosis,
these coronary arteries occlude over time, blocking blood flow to the muscles. – This means
that areas of the myocardium become ischemic, causing pain, especially during periods of high
oxygen demand.
– To counter this, the body seeks to increase heart rate and contractile force by increasing
sympathetic nerve stimulation.
– However, this only exacerbates the problem as it further increases O2 demand. – Therefore,
when treating angina, we strive to relax the heart and give more time to meet and reduce the
need for oxygen. There are 2 main types of angina:
Stable:
This is a chronic condition which occurs when >70% of the vessel is occluded. It has 3 main
defining criteria:
i) Constricting discomfort in the front of the chest/neck/shoulders/arms
ii) It is precipitated by physical exertion
iii) Relieved by rest or GTN spray in 5 minutes
– Typical angina has all 3 features, whereas atypical angina gives 2 of these features
Unstable:
This is chest pain that occurs at rest and is treated as part of Acute coronary syndrome
– Usually due to rupture of plaque which leads to incomplete occlusion of coronary artery
– Relieved by nitroglycerin with ST-segment depression
– However, there is high risk of progression to myocardial infarction (treated as ACS)
Diagnosis:
– 1st line is CT coronary angiography
– 2nd line is non-invasive functional imaging to look for reversible myocardial ischaemia
Management:
The management for stable angina involves 3 types of medication:
1) Prophylaxis –> Give Aspirin + Statin
2) Symptom Relief –> Glyceryl trinitrate spray – given to relieve symptoms after 5 minutes
, 3) Medical Therapy –> 1st line B-blocker or Ca2+ channel blocker (Verapamil or Diltiazem)
– If still symptomatic do dual therapy with Beta-Blocker + Dihydropyridine
– If dual therapy not tolerated –> Nicorandil or Ivabradine or Long-acting nitrate
Prinzmetal Angina
Myocardial Infarction
This is a term which means the irreversible death of cardiac myocytes, which occurs due to
ischaemia
– It is due to the rupture of a plaque which leads thrombosis and complete occlusion of the
artery
– It can be divided into an ST-elevated Myocardial infarction (STEMI) and non-elevated
(NSTEMI)
– It is usually seen in older men with vascular risk factors e.g. hypertension, diabetes, smoking
Symptoms:
– Acute crushing central chest pain that comes on rest (maybe no pain in elderly and diabetics)
– Pain radiates to jaw, neck, either/both Upper limb
– Sweaty and clammy
– Nausea, Vomiting and epigastric pain
Tests:
Blood Troponin:
Levels of troponin I indicate damage to myocardial cells. – Two samples taken 3h apart and
indicate possible infarction. – Levels rise 2-4 hours and peak at 24 hours
ECG:
This is helping in identifying ischaemic changes
STEMI = >1mm ST elevation in at least 2 consecutive limb leads
Or >2mm ST elevation in at least 2 consecutive precordial leads
Or new onset left-bundle branch block.
By seeing which leads the ST elevation occurs in, we can determine which artery has been
occluded:
– Lead V1-V4 = anterior territory –> LAD artery
