ischaemic heart disease Flashcards
(37 cards)
what 3 diseases comprise cardiovascular disease?
- coronary heart disease
- cerebrovascular disease
- peripheral vascular disease
what are the controllable risk factors for CHD?
- cigarette smoking
- diabetes
- high blood pressure
- high cholesterol
- obesity
what are the non-controllable risk factors for CHD?
- age
- family history of premature coronary disease
- previous heart attack
what is ischaemic heart disease (IHD) caused by?
it occurs due to atherosclerotic plaque build up within or one of more coronary arteries, thereby obstructing myocardial blood flow
what does ischaemic heart disease lead to?
an imbalance between myocardial oxygen supply and demand
what is myocardial ischaemia?
when there is a restriction in the normal increase in coronary blood flow which should occur in response to an increase in myocardial oxygen demand
what are the clinical manifestations of IHD?
- asymptomatic
- stable angina
- acute coronary syndromes: unstable angina, NSTEMI, STEMI
- long term: heart failure, arrhythmia and sudden death
what is the pathology of stable angina?
ischaemia due to fixed atheromatous stenosis of one or more coronary arteries
what is the pathology of unstable angina?
ischaemia caused by dynamic obstruction of a coronary artery due to plaque rupture with superimposed thrombosis and spasm
what is the pathology of myocardial infarction?
myocardial necrosis caused by acute occlusion of a coronary artery due to plaque rupture and thrombosis
what is the pathology of heart failure?
myocardial dysfunction due to infarction or ischaemia
what is the pathology of arrhythmia?
altered conduction due to ischaemia or infarction
what is the pathology of sudden death?
ventricular arrhythmia, asystole or massive myocardial infarction
what are the 3 characteristics of stable angina?
1) substernal chest discomfort of characteristic quality and duration
2) provoked by exertion or emotional stress
3) relieved by rest and/or nitrates within minutes
what conditions are included in acute coronary syndromes?
unstable angina and acute myocardial infarctions (STEMI and NSTEMIs)
how do you differentiate the difference between an acute MI, STEMIs and NSTEMIs?
the specific pattern of abnormality on the ECG
what cardiac enzyme is found in a raised level in patients who have an acute MI?
troponin
when is troponin released into the blood?
following an injury to the heart muscle and is diagnostic marker of an acute MI
when are troponin levels not rised?
in unstable angina
what is ACS characterised by?
the development of a thrombosis at the site of acute disruption of an atherosclerotic plaque within the wall of the coronary artery
after plaque disruption what does a thrombus result from?
- 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 ACS?
- discomfort/pain in the centre of the chest that lasts for more than a few minutes or recurs
- discomfort/pain radiating to other areas
- can occur at rest and/or with exertion
- not relieved immediately with sublingual GTN
what symptoms do the elderly or diabetic patients present with when suffering with ACS?
- breathlessness
- nausea or vomiting
- sweating and clamminess
what immediate assessment do you perform on patients with suspected ACS?
first: patient history, ECG and physical examination
then: risk stratification, cardiac biomarkers (troponin)
