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:
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:
