Acute coronary syndromes: presentation, management and treatment Flashcards
what is the 2nd most common cause of death in Scotland?
Heart disease
What is an Acute Coronary Syndrome?
Any sudden event suspected or proven to be related to a problem with the coronary arteries. ie Spontaneous plaque rupture & local thrombosis, with degrees of occlusion Problems arise due to myocardial ischaemia (reduction in the blood supply to the heart muscle) ie unstable angina, NSTEMI and STEMI
what is cardiac arrest? (4)
Abnormal heart rhythm not compatible with life - Ventricular fibrillation or tachycardia - Asystole Can occur during the acute phase of an MI Can occur late after an MI Can be unrelated to an MI
example of a chronic ischaemic heart disease
stable angina
examples of acute coronary syndromes? (2)
unstable angina myocardial infarction - STEMI (full thickness damage of heart muscle - transmural, more serious) or Non STEMI (subendocardial - partial thickness)
complete coronary occlusion causes what changes on an ECG initially and at 3 days?
ST elevation Q waves
partial coronary occlusion causes what changes on an ECG initially and at 3 days?
no ST elevation no Q waves
what is a transmural MI
a myocardial infarction that involves the full thickness of the myocardium STEMI
diagnosis of myocardial infarction
Detection of cardiac cell death/injury: +ve cardiac biomarkers AND one of: - symptoms of ischaemia - new ECG changes - evidence of coronary problem on coronary angiogram or autopsy - evidence of new cardiac damage on another test
what are cardiac biomarkers
Cardiac biomarkers are substances that are released into the blood when the heart is damaged or stressed. Measurements of these biomarkers are used to help diagnose acute coronary syndrome (ACS) and cardiac ischemia, conditions associated with insufficient blood flow to the heart.
Name some cardiac biomarkers
cardiac troponin - 2 types, 1 in STEMI 1 in NSTEMI myoglobin CK-MB
non-coronary causes of a troponin rise? (6)
Pulmonary embolism Cardiac contusion Anaemia Sepsis Renal failure Sub-arachnoid haemorrhage - burst blood vessel in the brain
types of MI
Type 1,2,3,4a,4b and 5 1 - spontaneous MI 2- imbalance of O2 supply/demand 3- sudden cardiac death 4a- MI associated with percutaneous coronary intervention 4b- associated with verified stent thrombosis via angiography or autopsy 5- MI associated with CABG
spontaneous MI can be due to what types of things?
atherosclerosis (but not always) Coronary vasospasm - cocaine, triptans (anti-migraine medication), 5-FU (chemotherapy) Coronary dissection - often younger, healthy females Embolism of material down coronary artery - thrombus or a tumour Inflammation of coronary arteries (vasculitis) Previous radiotherapy to chest causing fibrosis and stenosis of coronary arteries
MI typical history
Chest pain - may radiate to neck/arm - often they deny it is a “pain”, more a “discomfort” - Severe, but not “agony” - May be associated with nausea, sweating, breathlessness
cardiac risk factors (8)
Male Age Known heart disease Known high blood pressure High cholesterol Diabetes Smoker Family history of premature heart disease
Examination for ACS
May look very unwell or completely fine Often no specific features to find Ensure that you check: HR, BP Listen for murmurs, crackles in chest
key investigations for ACS
ECG bloods FBC - U&E, Glucose, lipids, cardiac enzymes CXR - cardiomegaly ECHO - regional wall abnormalities
what are hyperacute T waves
seen in transmural ischaemia (complete occlusion) are broad-based and symmetrical (normally asymmetric- sharper decline) usually with increased amplitude often associated with a depressed ST take off Almost always seen in conjunction with ST segment elevation
what are the T waves like in partial coronary occlusion
T wave inversion or may be normal ST depression
Problems in L anterior descending coronary artery causes what type of MI?
anterior MI
Problems in circumflex coronary artery causes what type of MI?
lateral MI - easily missed as may be little ECG change
posterior MI
easily missed because no ECG leads on chest usually the posterior wall is supplied b ythe RCA - see some inferior ST elevation left circumflex may supply posterior wall - may not see any ST elevation
posterior ECG leads
posterior myocardium is not directly visualised by the standard 12-lead ECG take the 6 anterior leads off and replace with V7, V8, V9