Myocardial infarction/Acute Coronary Syndrome Flashcards
How common is it?
CVD responsible for about 30% of UK deaths.
Who does it affect?
MIs are 3 times more likely in men than women
What causes it?
Rupture or erosion of the fibrous cap of a coronary artery atheromatous plaque with subsequent formation of a platelet-rich clot and vasoconstriction produced by platelet release of serotonin and thromboxane A2.
What risk factors are there?
Age male family history (counts as first degree relative has developed has developed ischaemic heart disease before the age of 50). Hyperlipidaemia cigarette smoking hypertension metabolic factors diet lack of exercise, psychosocial factors (work stress, lack of social support, depression), elevated CRP high alcohol intake high levels of coagulation factors.
How does it present?
Pain in the chest or arms, back or jaw lasting longer than 15 minutes.
Chest pain associated with nausea and vomiting, sweating or breathlessness, or a combination of these.
Chest pain associated with haemodynamic instability (for example systolic blood pressure below 90).
Chest pain of new onset, or is the result of an abrupt deterioration of stable angina; with pain occurring frequently with no or little exertion, and often lasting longer than 15 minutes. Can present with collapse, arrhythmia or new onset heart failure. 20% have no pain
Signs on examination?
May be no physical signs unless complications develop, although the patient often appears pale, sweaty and grey
Investigations
ECG (though a normal ECG does not rule out ACS).
Within hours there is ST segment elevation (>1mm in two or more contiguous leads) followed by a T-wave flattening or inversion. Pathological Q waves are broad (>1mm) and deep (>2mm) negative deflections that start the QRS complex.
Bloods (cardiac markers (troponin, creatinine kinase) FBC, creatinine, electrolytes, glucose, lipids)
Conditions that would present similarly
Aortic dissection
musculoskeletal pain
GORD
acute pancreatitis
