Valves, Malformations and Endocarditis Flashcards
4 cardiac valves
left (aortic and mitral)
right (pulmonary and tricuspid)
higher pressure cardiac valves
left (aortic and mitral)
lower pressure cardiac valves
right (pulmonary and tricuspid)
what valves more commonly fail
left (aortic and mitral)
- under higher pressure
2 ways left heart valves may fail
Aortic stenosis & incompetence
- Narrowed - restrict blood flow into aorta during systole,
- increasing work flow of ventricle
Mitral stenosis & incompetence
- Not closed properly – blood flow back in
how aortic stenosis and incompetence leads to left heart valve failure
- Narrowed - restrict blood flow into aorta during systole,
- increasing work flow of ventricle
how does mitral stenosis and incompetence lead to left heart failure
Not closed properly – blood flow back in
what is key to cardiac valve disease treatment
replace valve with prosthetic valve before permanent damage to heart
cardiac valve anatomy
Cusplets of collagen
Tied onto muscle wall of heart
Fibres connecting valves onto papillary muscles
- Papillary muscles designed to keep valves under tension
how can MI cause a valve to fail
damage to muscle - can cause valve to fail (acute valve failure)
valve stenosis
Not opening = build-up of pressure in left atrium, reduction in CO, higher pressure in pulmonary system
e.g. mitral valve (atrium to left ventricle)
mitral valve
left atrium to ventricle
tricuspid valve
right atrium to right ventricle
pulmonary valve
right ventricle to pulmonary artery
aortic valve
left ventricle to aorta
prevalence of cardiac valve disease
very common in the elderly and Downs
(Elderly - don’t notice as activity low)
- Breathless on exertion
- Tired
but rarely any symptoms - undiagnosed!
4 causes of aortic valve disease
Congenital abnormality
- Bicuspid aortic valve
- Formed the valve incorrectly when developing
- Can be in teens and 20s and need valve replaced
Myocardial infarction
- papillary muscle rupture
Rheumatic Fever
- Immunological reaction to streptococci
Dilatation of the aortic root - Syphilis - Aneurysm formation Stretch – valves pulled apart To do with disease of aorta not valve
congenital abnormality leading to cardiac valve disease
Bicuspid aortic valve
- Formed the valve incorrectly when developing
- Can be in teens and 20s and need valve replaced
how can MI lead to cardiac valve disease
papillary muscle rupture
how does rheumatic fever lead to cardiac valve disease
Immunological reaction to streptococci
how can dilation of aortic root lead to cardiac valve disease
Stretch – valves pulled apart
To do with disease of aorta not valve
- Syphilis
- Aneurysm formation
investigating valve disease
- Previously stethoscope
* Ultrasound
what is seen in an ultrasound investigation of heart
Realtime heart moving
- See valves open and close and muscle contracting
Easy to see where issue is
- Can identify moving liquid moving though heart
(Coloured for different flows; Red correct direction - through the valve)
- should have unidirectional flow
Doppler valve assessment?
- Quantity of problem
2 options for valve replacements
mechanical valve (e.g. ball and socket)
pig valves (porcine)
mechanical valves
made of metal in workshop
need to be on anticoagulants
- Blood will clot on unless use anticoagulant
need to follow SDCEP anticoagulant guidance for dental care
risk of endocarditis
- Maximise Oral Health
- Be sensitive to patient and surgeon needs
- Be aware of international disagreement in this area
- Sometimes antibiotics are given – case by case
advantages of pig valve
right size (similar heart size)
Natural valve leaflets (normal collagen)
Blood won’t stick to them anymore than they do in pig (no anticoagulant needed, e.g. children would have bleeding problem as fall over often)
disadvantage of pig valve
Pig valves last less (10 years) tissue will wear out, natural wear as removed from environment
- Fine for elderly as longer than life expectancy of patient (save anticoagulant complication)
- Not issue in child - by 20 get a proper metal valve which will last 30 years
when would you use a pig valve and mechanical valve
Pig valves - extremes of life
Longevity - metal valve
Every time replace - risk of death only want 2/3 in lifetime
what are congenital heart defects
Failure of normal development and fusion of embryonic heart
- Often undetected & asymptomatic
Suspect in ANY congenital defect (CLP, Downs)
- Any child with congenital defect is high risk of having higher risk of congenital cardiac malformation
- Not worked somewhere so likely multiple issues in genetics
when do congenital heart defects occur
Happen as you are forming as an embryo
Cardiovascular forms from 2 parallel circuits combine with 1 heart with 2 effective sides
- A lot join together or are separated
- May not work well
4 types of congenital heart defects
ATRIAL septal defects
VENTRICULAR septal defects
Patent ductus arteriosus
Great vessel malformations
when does the join between pulmonary artery and aorta need to shut
when you breath
Usually first half hour of before, after 1-2 days no blood going to pulmonary circulation from aorta
what happens when there is over fuse of atria
hole right to left side of atria, low pressure system so doesn’t notice blood going back to lungs
(common)
atrial septal defects
from one atria to another
Oxygenating the blood twice, no issues if volume of blood low
On X-Ray see
- Swelling on right side of heart (left of pic)
- Sticks close to spine usually
ventricular septal defects
Move blood from left to right side
Some left ventricle blood into pulmonary artery (normally aorta), then into lungs
- Left ventricle needs to work more to maintain CO as losing proportion through right ventricle
- Leads to heart failure unless managed
normally left ventricle contracts
squirt out aorta
normally right ventricle contracts
squirt into pulmonary artery
process of ventricle septal defect leading to right sided heart failure
blood into aorta and right ventricle and pump into lungs again,
increasing workload of right side (higher pressure system)
lead to right side failure
(less common, picked up and lower activity tolerance need to repaid before damage)
ductus arteriosus
runs from pulmonary artery to aorta
- Allows blood in fetus to move from right ventricle to aorta
Lungs expand on breath
- Easier blood to go through lungs then into aorta
- Ductus needs to close
ductus arteriosus allows
blood in fetus to move from right ventricle to aorta
Lungs expand on breath
- Easier blood to go through lungs then into aorta
- Ductus needs to close
closing of ductus arteriosus causes
co-arctation of aorta
closing carries onto aorta - so closed ductus and narrowed aorta
- Hard to pump to rest of body
Right arm BP normal, left arm low - arm artery coming off after narrowing
- Can live with but can lead to heart failure as more work
patent ductus arteriosus
Blood flow opposite direction
- Need to shut off
Remains open - aorta into lungs
- Like venricle septal defect
dental impact of congenital heart abnormaltiies
may have endocarditis risk
Guidance from Cardiologist required
- Check with cardiologist for infection risk in dental treatment
- case by case basis
Most are mild and undetected!
infective endocarditis
Infection of the endocardium
- Usually on the valves
Microbial colonisation of thrombi on endocardial surface abnormalities
- Many organisms implicated
number of new endocarditis cases each year
1400 (UK)
- 20 deaths
50% patients over 50
is there predisposing factors of endocarditis?
often none
- Rheumatic fever less common now
- Prosthetic valves more common now
7 physical findings for diagnosing infective endocarditis
Fever 90%
Heart murmur 85%
Embolic phenomena e.g. splenic or renal infarction, cerebral emboli >50%
Skin manifestations e.g. Osler nodes, spliner haemorrhages and petechiae 18-50%
Splenomegaly 20-57%
Septic complication e.g. pneumonia, meningitis 20%
Mycotic (infective) aneurysm 20%
3 organisms in infective endocarditis
- Streptococci
- Staphylococci
- Fungi
effect of infective endocarditis
Prolonged antibiotic treatment
- 4+ weeks of bactericidal treatment
- Often combinations of drugs
Cardiac valve damage
- Valve dysfunction
- Urgent valve replacement needed?
when is prevention of infective endocarditis possible
if ‘at risk’ patients identified in dentistry
- Medical history
- Prominent identification in case record
possible preventions of infective endocarditis
Avoid risk procedures?
Use antibiotic prophylaxis when needed?
NICE Guidelines 2008 – Review in 2015
Review of available evidence
- NO indication for Antibiotic Prophylaxis in literature of benefit
- Possible harm from ADR
Advise that Antibiotic Prophylaxis can be used in special circumstances
evidence of antibiotic prophylaxis not used in infective endocarditis prevention
NICE states that AB prophylaxis is ineffective
- not recommended routinely
ESC & AHA suggest that it is for highest risk patients
prevalence of infective endocarditis and morality
2150 cases of IE in UK annually
Incidence is rising
Up to 20% IE patients die on 1st admission – up to 50% overall
Up to 45% attributed to S. viridans
Survivors will have significantly reduced length & quality of life
dental role in infective endocarditis
Consequences of ABP must be discussed
Consequences of NO ABP must be discussed
- Advise high risk patients about the evidence for and against
Patient to discuss with cardiac team
- Dentist informed of decision
3 dental theorectical issues if prophylaxis is recommended
Is procedure to be performed ‘high risk’
Is patient wanting prophylaxis
What does SDCEP recommend in these circumstances
drug regime for infective endocarditis
Amoxycillin 3g oral 1hr before procedure – even if used recently
UNLESS ALLERGIC
Clindamycin 1.5g
Higher ADA risk – ONLY use if penicillin allergic
4 pointers of advice for reducing patient risk
Attendance for oral care
Rapid management infection
Maximal oral hygiene and prevention
Avoiding risk activity - piercings
central cyanosis caused by
congenital heart disease
peripheral cyanosis caused by
cold environment
when does cyanosis exist
when there is 5g/dl or more of deoxygenated Hb in the blood
May have Hb of 15 but only 10 carry O2
- Hard to get oxygen to tissues
need to fix or will become a permanent issue
signs of central cyanosis
Go blue
- Peripherally shut down
- Circulation to peripheral tissues will stop
- Blood will become saturated
Cyanosis throughout body including those with lots of blood flow (core tissues)
- Tongue, oral mucosa (usually always pink)
Finger clubbing
- Swelling of terminal digits of fingers
what is infective endocarditis
Infection of the endocardium
- Usually on the valves
Microbial colonisation (bacteria) of thrombi on endocardial surface abnormalities - Platelets to adhere to damaged endothelial surfaces and allowing vegetative build up
Many organisms implicated
- mainly oral streptococci
DENTAL PROCEDURES implicated in the cause
what main organisms are implicated in infective endocarditis
Many organisms implicated
- mainly oral streptococci
DENTAL PROCEDURES implicated in the cause
example of poor antibiotic prescription in dentistry
Dentists had poor understanding of the differing risks that cardiac problems had for endocarditis.
- Many patients came to expect antibiotics before dentistry - even thought it was unnecessary
Example: Rheumatic Fever – a condition commonly leading to prophylaxis pre 2008
However only those patients who had HEART VALVE DAMAGE from the condition (Rheumatic Heart Disease) actually needed prophylaxis. Usually this was Mitral valve disease (Small number)
- few dentists made this distinction or arranged Echocardiograms to see.
It was easier just to give an antibiotic before the dental procedure – just in case
cycle of infective endocarditis starting with surface abnormalities
surface abnormalities
haemodynamic changes
turbulence
platelet/fibrin deposition (thrombus)
vegetation
- as thrombus colonised by bacteria in blood
microbial attachment and multiplication
- enlarged and cause damage to tissue and endocardium
enlargement of vegetation
physical findings in diagnosis of endocarditis
Flu like then develop murmur/splint/haemorrhage, onset can be 6 weeks post procedure – hard to link
Physical findings
- Fever
- Heart murmur
- Embolic phenomena e.g. renal/splenic infarction, cerebral embol
- Skin manifestations e.g. Osler nodes, splinter haemorrhages and petechiae
- Splenomegaly
- Septic complications e.g. pneumonia, meningitis
- Mycotic (infective) aneurysm
effect of infective endocarditis
Prolonged antibiotic treatment
- 4+ weeks of bactericidal -treatment IV treatment
- Often combinations of drugs
Cardiac valve damage
- Valve dysfunction
- Urgent valve replacement needed?
Significant risk of Death from disease or its complications
how is prevention of infective endocarditis possible in dentistry
Prevention only possible if ‘at risk’ patients identified in dentistry
- From the Medical history
(Many had no previous history of endocardia issue)
- Prominent identification in case record (Susceptible to multiple episodes once had one)
what to do once find an ‘at risk’ of infective endocarditis in dentistry
Avoid risk procedures?
- Removing all teeth – not ideal
Use antibiotic prophylaxis when needed?
- Complicated prophylaxis protocols
- —Divide pt into risk categories
- —Oral or IV depending on perceived risk
2006 guidelines Tx for antibiotic prophylaxis dental treatment
Antibiotic prophylaxis for dental procedures may be supplemented with
- chlorhexidine gluconate gel 1% or chlorhexidine gluconate mouthwash 0.2%, used 5 minutes before procedure
- —no evidence
3 high risk cardiac failures requiring AB Prophylaxis according to BSAC 2006
High risk cardiac failures requiring antibiotic prophylaxis
- Previous infective endocarditis
- Cardiac valve replacement surgery i.e. mechanical or biological prosthetic valves
- Surgically constructed systemic or pulmonary shunt or conduit
dental procedures requiring antibiotic prophylaxis according to BSAC 2006
Dental procedures requiring antibiotic prophylaxis
- All dental procedures involving dento-gingival manipulation
Patients given AMOXYCILLIN and GENTAMYCIN IV before dental treatment which meant treatment had to be delivered in general hospital setting
5 types of cardiac patients that are not at risk of infective endocarditis
Coronary Artery Bypass Grafting
Angioplasty & Stent
Hypokinetic cardiac muscle (following an MI)
Implanted Pacemaker
Implanted Defibrillator
4 dental treatments that are at risk of infective endocarditis
INVOLVE DENTO-GINGIVAL MARGIN MOVEMENT
Extractions
Periodontal therapy
Implants (surgical)
Restorations
- If gingival margin involved or matrix used
2 dental procedures that are not at infective endocarditis risk
Endodontics
- Instrumentation in root canal only
Impressions
what was the impact on the NICE guidelines in 2008 on AB prophylaxis
prior AB prophylaxis used for patients with very low or no risk and exposing patients to treatment protocols and antibiotics that were not necessary
NO indication for Antibiotic Prophylaxis
- No indication from literature of benefit
- Possible harm from ADR (adverse drug reaction to antibiotic)
But: Is the lack of evidence the same as evidence of no risk
post 2008 dental efforts to reduce infective endocarditis focussed on
Dental efforts to be concentrated on reducing risk by reducing size and frequency of oral bacteraemia
- Develop every time eat, chew, brush teeth
- Small bacteraemia are frequent and normal throughout the day
3 dental orientated methods to reduces oral bacteraemis
Improve patient’s oral hygiene efforts
-Areas of plaque trapping and oral bacteria habitat can be removed as efficiently as possible
Remove areas of dental sepsis
- unrestorable carious teeth, teeth causing infection
Work at prevention of oral disease
Diet, hygiene, high fluoride content toothpaste
why was their controversy after the 2008 NICE guidelines
European and US Guidelines different than NICE
Cardiac Surgeons unhappy
- wanted antibiotics for some surgical groups – mainly valve replacements
Cardiologists less unhappy
- Valve pt in particular at unnecessary risk
Patients confused
consequences of NICE prophylaxis guideline review in 2015
NICE states that AB prophylaxis is ineffective
ESC & AHA (American and European) suggest that it is effective for the highest risk patients (divided pt population)
- Previous endocarditis
- Valve replacement surgery
- Certain congenital heart defects
2150 cases of IE in UK annually - Incidence is rising - Up to 20% IE patients die on 1st admission – up to 50% overall Up to 45% attributed to S. viridans - Dental cause
Survivors will have significantly reduced length & quality of life
recent 2015 review of NICE prophylaxis guidelines looked at
Groups at risk of developing infective endocarditis
Interventional procedures associated with risk of infective endocarditis should not use AB Prophylaxis
- Including dentistry
levels of bacteraemia
- regular bacteraemia reduced as much as possible
Prophylaxis regimen to be used
risks of prophylaxis use compared to none (NICE guidelines)
small risk and small death chance
NICE Guidance could potentially lead to increase number of pt having endocarditis and increase deaths
- Led to doctors and pts realising current guidance unmaintainable for UK
think of picture of outweighing risks
what was changed in the reviewed 2016 NICE Guidelines on prophylaxis
“Antibiotic prophylaxis against infective endocarditis is not recommended routinely”
Allow for situations where clinical need would outweigh guidance
- remained the same but with greater degree of flexibility
Guidance can be taken or not
- many NHS trusts take literally – dentists discourage from giving AB Prophylaxis even in extreme situations
Dental issues arisen due to NICE prophylaxis guidelines
How do I determine which patients should be offered AB prophylaxis?
- Didn’t help determine how should and shouldn’t
NICE gives no recommendation on which dental procedures should be covered
NICE gives no advice on the prophylaxis regime to be used
what are the SIPCEP prophylaxis guidelines for all dental team
Practical recommendations
Includes:
- Patient selection for discussion (Patients at risk)
- How to advise a patient
- —–Importance of GENERAL oral health measures, Seek guidance from surgeon
- What antibiotic regime to give if decided by the patient & doctor
- What dental procedures to cover
Montgomery issues for informed consent for prophylaxis
Consequences of ABP must be discussed
Consequences of NO ABP must be discussed
For cases who are ‘high risk’ undergoing invasive dental procedures – dentogingival manipulation.
Pt fully aware of both sides, see evidence and decide themselves
how should the decision regarding prophylaxis be carried out
Made by patient and their physician
Communicated to dentist in writing
Only for procedures likely to produce a significant bacteraemia
- E.g. MANIPULATION OF DENTO-GINGIVAL JUNCTION
Prophylaxis given if pt wished
- Dentist is to implement pt wishes whatever they may be for appropriate dental procedures
Pt risk assessed on Mx History
Discuss with physician and communicate pt wishes to dentist
So prophylaxis can be used when wanted for appropriate dental procedures
most effective ways at preventing infective endocarditis in dentistry are (4)
NICE Guidelines 2008
All the advice about reducing patient risk STILL applies.
- Attendance for oral care
- Rapid management infection
- Maximal oral hygiene and prevention
- Avoiding risk activity – piercings
drug regime for AB prophylaxis
Amoxycillin 3g oral 1hr before procedure – even if used recently, Unless allergic
- In surgery so can control any reaction that occurs
Clindamycin 1.5g
- Higher ADA risk – only use if penicillin allergic
