Endocarditis Flashcards
Strongest risk factor for infective endocarditis
Previous episode of endocarditis
Risk factors for IE
Rheumatic valve disease Prosthetic valves Congenital heart defects IVDU Recent piercings
Valve most commonly affected by IE
Mitral valve
Most common organisms that cause IE
Staph aureus(now most common, esp in IVDUs)
Strep viridans(historically most common)
Coagulase negative staph such as staph epidermis
What are IEs from strep viridans linked to
Poor dental hygiene or following a dental procedure
What are IEs from staph epidermis linked to
Staphylococcus epidermidis
commonly colonize indwelling lines and are the most cause of endocarditis in patients following prosthetic valve surgery, usually the result of perioperative contamination.
Non-infective causes of IE
systemic lupus erythematosus (Libman-Sacks)
malignancy: marantic endocarditis
Culture negative causes of IE
prior antibiotic therapy Coxiella burnetii Bartonella Brucella HACEK
What is HACEK
Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella
Pathophys of IE
Endocardial injury → adherence of platelet and fibrin plug → circulating micro-organisms leads to secondary infection of plug → activation of coagulation cascade → adherence of more fibrin and platelets → growth of plug/vegetation
Symptoms of IE
Fever(90%) Chills Anorexia Weight loss Malaise Arthralgia Night sweats Abdominal pain
Signs of IE
Heart murmurs(usually only present in left-sided) Cutaneous manifestations Janeway lesions Osler nodes Roth spots
Cutaneous manifestations of IE
Petechiae on extremities or mucous membranes (30%) Splinter haemorrhages (reddish-brown linear lesion on the nail bed)
What are janeway lesions
non-tender macules on palms and soles, more associated with acute onset
What are Osler nodes
tender nodules on fingers and toes
What are Roth spots
haemorrhagic retinal lesions with a pale centre
Poor prognostic factors for IE
Staphylococcus aureus infection
Prosthetic valve (especially ‘early’, acquired during surgery)
Culture negative endocarditis
Low complement levels
Indications for surgery in IE
severe valvular incompetence
aortic abscess
infections resistant to antibiotics/fungal infections
cardiac failure
recurrent emboli after antibiotic therapy
What can indicate an aortic abscess in IE
often indicated by a lengthening PR interval
Suggested antibiotic therapy in native valve IE
Amoxicillin
Suggested antibiotic in IE caused by staph
Flucloxacillin
Suggested antibiotic in IE caused by fully-sensitive strep
Benzylpencillin
Criteria used to diagnose IE
Modified Duke criteria
Major criteria for IE diagnosis
Positive blood cultures
Evidence of endocardial involvement(Echo, new valvular regurg)
Blood culture recommendation for IE
At least 3 samples from different sites over 30-60 mins is recommended.
Adequate blood culture samples must be taken before starting any antibiotics, regardless of the clinical decision to start empirical antibiotics or to delay treatment.
First line imaging ix for IE
Transthoracic echo usually
Transoesophageal echo has a higher sensitivity and is preferred if available
Cardiac complications of IE
Valvular insufficiency, if left untreated, leading to congestive heart failure is the most common
Pericarditis
Perivalvular abscess
Complications of IE from metastatic infection
Embolisation (which can lead to infarction and subsequent damage to various peripheral tissues)
Metastatic abscess formation
Mycotic aneurysms
Type of complications - right-sided vs left sided IE
Systemic emboli affecting the brain, kidneys, spleen, and other soft tissues commonly occurs in left sided IE whereas pulmonary emboli most commonly occur in right sided IE.
Pulmonary complications of IE
Septic pulmonary emboli (75% of cases with right sided IE) can manifest as pulmonary infarction or can lead to to a pulmonary infection, abscesses, pleural effusion, and empyema.
neurological complications of IE
Neurological complications (40%) (including embolic stroke, intracerebral haemorrhage, cerebral abscess, meningitis, encephalopathy, seizures)
Renal complications of IE
The most common renal complications include renal infarction, abscess (which are both secondary to septic embolisation) can present with isolating clinical features eg. costovertebral angle tenderness or with acute renal failure.
MSK complications of IE
Vertebral osteomyelitis
Septic arthritis
Psoas abscess
Causes of myocarditis
Viral - coxsackie B, HIV Bacterial - diphtheria Lyme disease Toxoplasmosis Autoimmune
Which drug is associated with myocarditis
Doxorubicin
Presentation of myocarditis
usually young patient with an acute history
chest pain
dyspnoea
arrhythmias
ECG changes in myocarditis
tachycardia
arrhythmias
ST/T wave changes including ST-segment elevation and T wave inversio
Mx of myocarditis
treatment of underlying cause e.g. antibiotics if bacterial cause
supportive treatment e.g. of heart failure or arrhythmias
Complications of myocarditis
heart failure
arrhythmia, possibly leading to sudden death
dilated cardiomyopathy: usually a late complication
