9. Infective Endocarditis and AF Flashcards
What is endocarditis
inflammation of the inner layer of the heart
what are most cases of endocarditis due to
a microbial infection
true or false; any area that is exposed to turbulent blood flow can be affected by endocarditis
true
the microbial infection needs to get into the blood stream and so how does this occur
through an open wound
during dental or surgical procedure
by using an infected needle or illicit substance
what. are some risk factors for infective endocarditis
prosthetic valves
congenital heart defects
rheumatic heart disease
intravenous drug abuse
With infective endocarditis it is important to identify the microbial cause;
- what is the most common cause
- viridian’s streptococci (found in the mouth)
- stap aures (contracted from IV drug use into the skin)
- stap epidermis (likes prosthetic valvue)- thorugh valve surgery and IV catheter
can also get enterococcus faecalis and strep Boris from colorectal cancer or UC
true or false; blood cultures will grow fungal infections
FALSE; blood cultures will not grow fungal infections
what is the normal presentation of infective endocarditis
a new fever and a new murmur due to turbulent flow
an infection in the heart can dislodge and become watts known as septal emboli. What is it called when
a) it lodged in tech finger nails
b) it lodged in the palms or soles
c) in the eye
a) splinter haemorrhages
b) Janeway lesions
c) roth spots
what are Osler nodes
antigen-antibody complexes that are nodules found on the distal pads of the digits
what other non-specific is a sign of infective endocarditis
petechiae
blood culture negative infective endocarditis (BCNIE) occurs in up to 31% of all cases and this most commonly raised as a consequence of
previous antibiotic administration
hw do you diagnose infective endocarditis
the modified dukes criteria
need 2 major criteria OR
1 major and 3 minor criteria OR
5 minor criteria
Name the major criteria for diagnosing infective endocarditis
- Positive blood culture for IE: typical micro-organism consistent with IE from two separate blood cultures
- Evidence of endocardial involvement
- Positive echocardiogram for IE;
name the minor criteria for diagnosing infective endocarditis
- Predisposition: predisposing heart condition or IV drug use
- Fever: temperature greater than 38 degrees
- Vascular phenomena; major arterial emboli, septic pulmonary infarct, intracranial haemorrhage, conjunctival haemorrhage and Janeway’s lesions
- Immunological phenomena: glomerulonephritis, Osler’s nodes, Roth’s spots (eyes) and rheumatoid factor
- Microbiological phenomena: positive blood cultures but does not meet a major criterion as noted above or serological evidence of active infection with organism consistent with IE
- PCR: broad range PCR of 16S
- Echocardiographic findings consistent with IE but do not meet a major criterion as noted above
People who present with what common symptoms could have underlying AF
breathlessness/dysponea palpitations syncope/dizziness chest discomfort stroke/transient ischemic attack
what score do you use to assess the risk of a stroke in people with AF
CHA2DS2-VASc score
In patients with AF what is their pulse described as
irregularly irregular
What should be controlled first in people with AF; the rate or the rhythm and what drugs would you use
Rate should be controlled in preference to rhythm control
- use beta blocker. or a rate limiting calcium channel blocker as initial mono therapy
give an example of a rate limiting calcium channel blocker
verapamil and diltiazem
if mono therapy doesn’t work for AF rate control then what therapy should you consider
any 2 drugs from the following;
Beta blocker
Diltiazem
Digoxin
what is a major risk factor for people who have AF
blood flow will be turbulent and so there will be areas of stasis of blood flow so risk of clots forming
- more risk if the patient has been in AF for more than 48 hours
why do you not just cardiovert a patient in AF
- there is a risk they have a blot clot if the patient has been in AF for more than 48 hours and so you could dislodge the clot and cause an embolic stroke
How does someone with AF usually present
palpitations
SOB
syncope
symptoms of associated conditions (eg stroke, sepsis or thyrotoxicosis)
what does AF look like on an ECG
absent P waves
narrow QRS complex tachycardia
irregularly irregular ventricular rhythm
what is the difference between valvular and non-valvular AF
valvular- patients with AF who also have moderate or severe mitral stenosis or a mechanical heart valve
non-valvular is any other valve pathology or no valve pathology at all
what are the most common causes of AF
remember that AF affects mrs SMITH
SMITH Sepsis mitral valve pathology Ischemic heart disease thyrotoxicosis hypertension
what are the two principles that need to be treated in AF
rate and rhythm control
Anticoagulation to prevent stroke
NICE guidelines suggest that all patients with AF should have rate control as first line unless …….
there is a reversible cause for their AF
their AF is of new onset (less than 48 hours)
their AF is causing heart failure
then remain symptomatic despite being effectively rate controlled
how is rate control managed with drugs
- Beta blocker is first line (e.g. atenolol 50-100mg once daily)
- Calcium-channel blocker (e.g. diltiazem) (not preferable in heart failure)
- Digoxin (only in sedentary people, needs monitoring and risk of toxicity)
how is rhythm control treated
through cardioversion
if a patient has been in AF for more than 48 hours and they are stable they need have delayed cardioversion rather than immediate cardioversion
needs to be anti coagulated for a minimum of 3 weeks prior to cardioversion (due to chance they have developed a blood clot in atria)
what is the first line treatment for pharmacological cardioversion
Flecanide Amiodarone ( drug choice in patients with structural heart disease)
what is theming term medical rhythm control treatment
- Beta blockers are first line for rhythm control
- Dronedarone is second line for maintaining normal rhythm where patients have had successful cardioversion
- Amiodarone is useful in patients with heart failure or left ventricular dysfunction
what is paroxysmal AF
this is where the AF comes and goes in episodes, usually not lasting more than 48 hours
-pt should still be anticaoguluated based on CHADSVASc score
what is the treatment for paroxysmal AF and what are the cautions
‘pill in the pocket’ approach using flecanide
n.b should avoid flecanide in atrial flutter as it can cause AV conduction and result in significant tachycardia
what is the CHA2DS2-VASc score used for
to assess whether patients with AF should be started on anticoagulation
the higher the score, the higher the risk of developing a stroke of TIA
- note that there is no role for aspirin in preventing stroke in AF
what score is used to assess the risk of a major bleed whilst on anticoagulation
HAS-BLED
what does CHA2DS2-VASc stand for
C – Congestive heart failure H – Hypertension A2 – Age >75 (Scores 2) D – Diabetes S2 – Stroke or TIA previously (Scores 2) V – Vascular disease A – Age 65-74 S – Sex (female)
what does HAS-BLED stand for
H – Hypertension A – Abnormal renal and liver function S – Stroke B – Bleeding L – Labile INRs (whilst on warfarin) E – Elderly D – Drugs or alcohol
