Cardiology Flashcards
what is infective endocarditis?
inflammation of the endocardium caused by infection
what are the risk factors for infective endocarditis?
IV drug users pre-existing valvular disease patients with prosthetic valves males poor dental health
what are the common causative organisms for infective endocarditis?
oral bacteria - streptococcus
staphylococci - more common in prosthetic valves
what are the symptoms and signs of infective endocarditis?
- fever
- night sweats
- weight loss
- lethargy
- anorexia
- pleuritic chest pain
- tachycardia
- new or evolving murmur
- pericardial rub
- laneway lesions / oilers nodes
- clubbing
- splinter haemorrhages
- petechiae
- neurological deficits due to emboli causing stroke
- signs of cardiac failure in advanced disease
what criteria is used to diagnose infective endocarditis?
Modified duke criteria
what investigations are done when suspecting infective endocarditis?
- At least 3 paired blood cultures (aerobic and anaerobic), taken at least 30 minutes apart from different sites - before antibiotics are given
- serological testing (since blood cultures can be negative)
- inflammatory markers - CRP and ESR (raised)
- FBC - WCC raised
- Transthoracic, sometimes transoesophageal echocardiography - to look for signs of infection
- ECG
- rheumatoid factor (part of duke criteria)
what is the management of endocarditis whilst awaiting blood culture results?
IV antibiotics for at least 4 weeks:
- native valve endocarditis - amoxicillin
- native valve endocarditis, with severe sepsis - vancomycin and gentamycin
- native valve endocarditis, severe sepsis and risk factors for enterobacteria - vancomycin + meropenem
- prosthetic valve endocarditis - vancomycin + gentamicin + rifampicin
- supportive care - controlling airway, breathing and circulation
- surgery for acutely ill patients with decompensated heart failure to remove infected tissue and repair or replace affected valves
what is an acute coronary syndrome?
thrombus formation in a coronary artery lumen causing obstruction of the artery which leads to a reduction in blood flow to the myocardium.
- Unstable angina
- NSTEMI
- STEMI
describe the ischaemia in STEMI and NSTEMI
there is only partial occlusion of the artery in NSTEMI - there is infarction but the ischaemia is only subendocardial
there is complete occlusion of the artery in a STEMI, the ischaemia is transmural
what are the symptoms and signs of an acute coronary syndrome?
- chest pain - central, retrosternal, crushing or tight (radiates to left arm, neck or jaw), occurs at rest
- dyspnoea (ischaemia can cause left ventricular systolic impairment)
- there may be no clinical signs
- clammy, sweaty and pale (pain and reduced cardiac output causes activation of SNS)
- murmur, cyanosis, heart failure (if ischaemia has induced an arrhythmia or acute heart failure)
what investigations are carried out when suspecting MI?
- ECG
- Chest Xray (to exclude pulmonary oedema and aortic dissection)
- FBC
- U&Es
- CRP (raised)
- lipid profile (cholesterol, triglycerides - risk factors for IHD)
- cardiac markers (troponin, creatinine kinase - raised in MI - diagnostic)
- coronary angiogram
what are the signs of an NSTEMI on ECG?
ST normal/depressed
T wave flattened/inverted
what are the signs of an STEMI on ECG?
ST elevation
T wave flattened / inverted
pathological Q wave
what is the management for an MI?
- Dual antiplatelet therapy (aspirin (300mg) + clopidogrel)
- Analgesics (IV nitrates, Opiates with an antiemetic (domperidone))
- anticoagulants (LMWH)
- Percutaneous coronary intervention
- thrombolytics (reteplase) if no access to PCI within 120 mins (for STEMI)
what are all patients given following MI?
- ACE inhibitors (lisinopril) (in LV dysfunction, to lower BP and therefore afterload)
- dual anti platelet therapy continued for 1 year (aspirin + clopidogrel)
- beta-blocker (for 1 year or indefinitely if there is LV dysfunction)
- statins (atorvastatin)
- cardiac rehabilitation (stop smoking, diet advice, lose weight, control BP, regular exercise programme)
