congenital heart defects and infective endocarditis

Question 1

cyanosis

Answer 1

increase of deoxygenated Hb

Question 2

peripheral vs central cyanosis

Answer 2

peripheral - cold environment , slow circulation sees more O2 taken out of Hb in colder tissues e.g fingers toes
central - congenital heart disease - oxygenated and deoxygenated blood mixing

Question 3

doppler ultrasounds

Answer 3

used to investigate congenital heart defects

Question 4

atrial septal defects

Answer 4

occur between L and R atria
greater pressure in L so oxygenated blood moves from L to R
not risk of central cyanosis as oxygenated blood being pumped but chance of heart failure as less of it getting pumped
small endocarditis risk

Question 5

ventricular septal defects

Answer 5

occur between L and R ventricles
greater pressure in L so oxygenated blood moves from L to R
not risk of central cyanosis as oxygenated blood being pumped but chance of heart failure as less of it getting pumped
greater endocarditis risk as more turbulent blood flow

Question 6

co arctation of aorta

Answer 6

aorta narrower just after carotid branch

upper body unaffected but lower body sees less blood flow

Question 7

patent ductus arteriosus

Answer 7

ductus arteriosus remains open after birth meaning aorta and pulmonary artery remain connected
risk of excess blood flow to lungs

Question 8

infective endocarditis

Answer 8

infection of the endocardium (innermost layer of the heart that lines the chambers and valves)

Question 9

describe the process of infective endocarditis (4 stages)

Answer 9

1 - bacterial entry , usually from mouth into circulation
2 - bacteria adhere and settle on previously damaged endocardium
3 - bacteria will colonise a thrombus and multiply casuing damage and spread of infection
4 - leads to vegetation on valves causing thickening and damage

Question 10

what cardiac ptx are not at increased risk of endocarditis

Answer 10

CABG
angioplasty and stent (PCI)
implanted pacemakers and defibs

Question 11

bacteraemia

Answer 11

bacteria present in the bloodstream

Question 12

what dental procedures pose an endocarditis risk

Answer 12

those involving manipulation of the dento-gingival junction and production of a bactaeremia
examples : extraction ,periodontal therapy , restorations only if gingival margin involved or matrix band used

Question 13

what may be considered when performing bacteraemia producing procedures on its at high risk of developing infective endocarditis

Answer 13

antibiotic prophylaxis

Question 14

why is good OH essential in ptx with an endocarditis risk

Answer 14

good OH means less chance of oral diseases and needing treatment so no bacteraemia producing procedures needed
also if procedure is needed size and frequency of bacteraemias will be reduced

Question 15

what is the currrent antibiotic prophylaxis used in at risk ptx

Answer 15

3mg amoxycillin