Theme 3: Lecture 7 - Ischaemic heart disease Flashcards
What comprises cardiovascular disease
- Coronary heart disease
- Cerebrovascular disease
- Peripheral vascular disease
Coronary heart disease
Build up of cholesterol deposits in the coronary arteries
Cerebrovascular disease
Build up of cholesterol deposits in the arteries supplying the brain
Peripheral vascular disease
Build up of cholesterol deposits in arteries of the lower limb
Controllable risk factors for CHD
Cigarette Smoking Diabetes High blood pressure High cholesterol Obesity
Non controllable risk factors for CHD
Age
Family history of premature coronary disease
Previous heart attack
According to the Framingham heart study, does your risk of CHD increase with an increasing number of risk factors
yes
How does ischaemic heart disease cause myocardial ischaemia
- IHD occurs due to atherosclerotic plaque build up within one or more coronary arteries, obstructing myocardial blood flow
- This leads to an imbalance between myocardial oxygen supply and demand
- Restricts the normal increase in coronary blood flow which should occur in response to increase in myocardial oxygen demand
What are the clinical manifestations of ischaemic heart disease (8)
- Asymptomatic
- Stable angina
- Acute coronary syndromes (Unstable angina, NSTEMI, STEMI)
Long-term:
- Heart failure
- Arrhythmias
- Sudden death
What pathology causes unstable angina
ischaemia caused by dynamic obstruction of a coronary artery due to plaque rupture with superimposed thrombosis and spasm
Definition of typical angina
Meets all 3 of the following criteria:
- substernal chest discomfort of characteristic quality and duration
- provoked by exertion or emotional stress
- relieved by rest and/or nitrates within minutes
Definition of atypical angina
Meets 2 of the following criteria:
- substernal chest discomfort of characteristic quality and duration
- provoked by exertion or emotional stress
- relieved by rest and/or nitrates within minutes
Definition of non anginal chest pain
Lacks or only meets one of these criteria:
- substernal chest discomfort of characteristic quality and duration
- provoked by exertion or emotional stress
- relieved by rest and/or nitrates within minutes
First line treatment for angina relief
Short acting nitrates plus:
-beta blockers or calcium channel blockers
-
What is second line treatment for angina
consider PCI stenting or CABG
What do acute coronary syndromes include
- unstable angina
- MI (STEMI and NSTEMI)
What is the diagnostic marker for an acute MI
Troponin which is measured in a blood test
When are troponin levels elevated
- In acute MI
- Not in unstable angina
How are STEMIs and NSTEMIs differentiated
by the specific pattern of abnormality on the ECG
What is ST elevation on an ECG a marker of generally
complete coronary occlusion
What is incomplete occlusion associated with on an ECG
- ST depression
- Variable T wave abnormalities
- Normal ECG
How to acute coronary syndromes develop
ACS is characterised by the development of a thrombosis at the site of acute disruption of an atherosclerotic plaque within the wall of the coronary artery
How do thrombi develop following plaque disruption in an artery
- Adherence, activation and aggregation of platelets
- Thrombin and fibrin production via the coagulation cascade (and thrombin release from platelets)
- Vasoactive molecules released from platelets which cause vasoconstriction
What are the classical symptoms of acute coronary syndromes
- Discomfort/pain in the centre of the chest that lasts for more than a few minutes or recurs
- Discomfort/pain radiating to other areas, e.g. left arm/jaw/back
- Can occur at rest and/or with exertion
- Not relieved immediately with sublingual GTN
