Infective Endocarditis

Question 1

describe how blood moves through the heart

Answer 1

deoxygenated blood
- vena cava
- right atrium
- tricuspid valve
- right ventricle
- pulmonary artery

blood now oxygenated
- pulmonary vein
- left atrium
- mitral valve
- left ventricle
- aorta

Question 2

what is systole and diastole

Answer 2

diastole
- ventricles relax
- tri and mit valves open
- allowing blood flow into atria

systole - at the end, pump out
- ventricles contract = higher pressure
- tri and mit valves close
- valves to pulm. artery and aorta open

Question 3

what are the “heart strings” connected to the valves?

Answer 3

chorda tendinae

Question 4

function of heart valves?

Answer 4

push blood in one direction
and to prevent back flow

Question 5

what are the 2 issues with valves during heart valve disease?

Answer 5

1. Incompetent Valves - don’t prevent regurgitation
   - can promote thrombosis
2. Stenosis - valves are too stiff to open
   - turbulent flow
   - increases the workload on the heart = hypertrophy
   - jet damage to the endothelium = lead to blood clots

Question 6

describe the foetal circulation.

Answer 6

the lungs are not functional

oxygenated blood from placenta
lungs are by-passed in two ways

1. communication from the right atrium to the left VIA FORAMEN OVALE
2. any blood in the pulmonary circuit
   - has communication between pulmonary artery direct to the aorta = DUCTUS ARTERIOSUS

Question 7

Congenital Heart Disease
- 2 Types
- 2 aetiologies
- epidemiology

Answer 7

TYPES
Cyanotic Congenital Heart Disease
- blue discolouration around mouth and peripheries

types:
- Tetralogy of Fallot
- Transposition
- Tricuspid Atresia

Acyanotic Congenital Heart Disease
- lungs are functional but cause issues over time

AETIOLOGY

1. heart fails to develop normally
   - narrow valves
   - artrial/ventricular septal defect (hole)
   - dextrocardia - entire heart is wrong way round
   - transposition of great veins - vena cava and pulmonary vein are swapped
2. heart fails to complete the changes at birth
   - patent ductus arteriosus - doesn’t close
   - patent foramen ovale

epidemiology - 0.2%
- more common in those with developmental conditions - Down’s

Question 8

Tetralogy of Fallot
- definition

Answer 8

a congenital heart disease, 4 specific heart defects

1. Ventricular Septal Defect
2. Right Ventricular Hypertrophy
3. Pulmonary Stenosis
4. Overriding Aorta - aortic valve can receive from left and right ventricles

= poor lung perfusion
= poor blood oxygenation
= heart failure

Question 9

what are the 3 aspects of Virchow’s Triad

Answer 9

blood flow
vessel wall
coagulation factors

Question 10

valvular heart disease
- 2 types and their epidemiologies

Answer 10

1. Rheumatic heart disease
   - caused by group A streptococcal A bacterial infection
   - pharyngitis
   - develop non-specific systemic symptoms
   = fever, arthralgia, ECG changes
   - causes auto-immune damage
   = endocardial and valve lesions
   - more common in sub-saharan Africa and developing countries - poor nutrition, poor wealth
2. Calcification/Degeneration of Valves
   - very common in developed countries
   - 20% >80 years
   - smoking, high BP, cholesterol and obesity

Question 11

whats the effect of valvular and congenital heart disease?

Answer 11

1. reduced pumping efficiency
   = leads to heart failure
   - shortness of breath
   - can’t exercise easy
   - failure to thrive in children
2. jet damage to endocardium
   - leads to stasis
   - affects virchows triad - vessel wall
   - may lead to mural thrombosis
   = risk of endocarditis

Question 12

management for valvular heart disease
- 2 treatments
- what needs to be addressed?
- management

Answer 12

TAVI - transcatheter aortic valve implant
mitral valve replacement

address
- Virchow’s triad
- the foreign material
- the risk of thrombosis and embolism

management
- with warfarin or NOAC’s - non-vitamin K antagonist coagulants

Question 13

list one treatment for valvular heart disease and its relevance to dentistry, particularly ADC

Answer 13

prosthetic heart valves

px may come in before having a TAVI - transcatheter aortic valve implant
- dental issues need to be addressed before implant is placed
= to reduce risk of endocarditis and infect the new valve

• px must have no dental infections prior to the procedure

Question 14

Infective Endocarditis
- defintion
- epidemiology
- risk factors
- aetiology
- signs
- prognosis

Answer 14

infection of the endocardium, including heart valves

epidemiology
- 0.002-0.005%

risk factors
- prosthetic valves/valve abnormalities but can be in normal hearts too
- untreated congenital heart disease
- valvular heart disease
- IVDA - intra-venous drug users
- immunocompromised
- a previous episode of IE
BASC susceptible heart+bacteraemia

aetiology
- bacteraemia in the blood, set on the valves
- fibrin, bacteria, WBC accumulate on valves = vegetation

signs
- septic signs - fever, rigor - cold with hot sweats, malaise, weight loss
- cardiac signs - change in or new heart murmur, shortness of breath, heart failure
- systemic problems - vasculitis - eye, kidney (splinter haemorrhages and on torso, hands and nails)

prognosis - 6-30% mortality

Question 15

Infective Endocarditis causes a vegetation on the valves, whats the effect of this?

Answer 15

give rise to embolisms

• stroke
• mesenteric - damages bowel
• renal - damages kidney
• limbs etc

Question 16

bacteraemia
- where can it occur from?

Answer 16

instrumentation of areas with high bacterial load

• dental procedures
• upper and lower GI
• urogenital tract

Question 17

what is a NICE guidance against Infective Endocarditis but what does SDCPEPP say

Answer 17

to not prescribe antibiotic prophylaxis for people undergoing dental procedures

SDCEPP says that px with heart murmurs don’t need antibiotic prophylaxis
- unless they’re in the special consideration group of:
- previous IE
- prosthetic valves
- NO pacemakers

Question 18

what should you mention to a px if you are not prescribing antibiotics?

Answer 18

• the risk of antibiotics > risk of IE
• no longer routinely recommended from research
• importance of OHI
• symptoms may appear as IE

Question 19

what should you mention to a IE risk px when you are prescribing antibiotics

Answer 19

side effects
- hypersensitivity
- anaphylaxis
- antibiotic-related colitis from c.dif

• good oral health
• be aware of signs and symptoms of IE
• risk of non-dental procedure - tattoos and piercings