Cardiovascular Disorders Flashcards
What is the most common form of structural malformations
Congenital heart disease
Causes of Chd
Genetic chromosomal - 8%
Teratogens
Idiopathic (most common)
Egs of teratogens causing CHD? Cause what?
Congenital rubella (eg PDA, pulmonary stenosis) Alcohol (ASD, VSD)
Chromosomal disorders causing CHD ? Eg?
Downs - AVSD
Turners - aortic stenosis, coarctation
Williams - supra valvular AS
Chromosome 22 deletions
What are the two types of CHD ? Why?
Acyanotic (L–>R shunts)
Cyanosis (R->L shunts)
Egs of L->r shunts
VSD -30%, PDA -12%, ASD -7%. Outflow obstruction (pulmonary (7%) / aortic (5%) stenosis, coarctation 5%)
Egs of R->L shunts
Tetralogy of fallot 5%
Transposition of the great arteries 5%
Outline the fetal circulation.
Placenta ->?
Pressure highest?
What causes change in pressures
Placenta delivers oxygenated blood to R atrium
Blood is unable to flow through lungs -> R side pressure Highest.
Blood flows through ductus arteriosus and foramen ovale.
Birth lungs expand -> decreased R sided pressure (smaller than left)
How does CHD present
Antenatal uss diagnosis Heart murmur Cyanosis Shock (low cardiac output) Cardiac failure
What are the two types of ASD
Ostium secundum defect (80%)
Partial AVSD + ostium primum defect
Where does an ostium secundum defect occur ? Who is it more common in?
High in atrial septum involving foramen ovale
2x more common in girls
Where is a partial AVSD ? What 2 things characterise it
Defect in atrioventricular septum
1- inter atrial communication between bottom end of atrial septum and atrioventricular valves (primium ASD)
2 - abnormal AV valves (typically mitral regurgitation )
Clinical features of ASD
Abnormal right ventricular impulse
Widely split and fixed second heart sound (s2)
Tricuspid flow murmur -> rumbling mid diastole murmur at LEFT STERNAL EDGE
Pulmonary flow murmur -> soft ejection systolic murmur in PULMONARY AREA
Symptoms of ASD
None - common
Recurrent chest infections / wheeze
Heart failure
Arrythmias - 4th decade onwards
Investigations for ASD ? What is seen?
CXR - cardiomegally, enlarged pulmonary arteries and increased pulmonary vascular markings (all NON SPECIFIC)
ECG - right ventricular hyper trophy (R AXIS DEVIATION), partial right bundle beach block (MaRRoW)
Echo - diagnostic without cardiac catheterisation
Management of ASD ? Aim ? What age ?
Surgical to prevent heard failure and arrythmias
3-5 best
What is the surgery for secundum ASD
Cardiac catheterisation with insertion of occlusive device
Surgical management of partial AVSD
Open surgical correction required
What 2 factors alter the prognosis of VSD
Size of defect and its position in septum
Development of changes due to L->R shunting
What changes occur in eisenmenger syndrome?
Increased blood to lungs -> arteries become stuff and narrow -> pressure becomes so great the shunt reverses. R->L
DANGEROUS
Symptoms of small
Asymtomatic
Signs of small VSD
Pan systolic murmur (sometimes palpable thrill) at the lower left sternal edge
Investigations for small VSD
CXR and ECG - normal
Echo - can demonstrate haemodynamic effects using Doppler echocardiography
Treatment of small VSD
Most close spontaneously - followed with ECG and murmur
While VSD present - endocarditis prophylaxis before dental extractions and gold dental hygiene
How big are large VSDs
Same size or bigger than aortic valve
Symptoms of large VSDs
Heart failure and failure to thrive after 1 week old
Recurrent chest infections
Signs of large VSDs
Acute precordium
Harsh pan systolic murmur loudest in 3rd/4th IC space (may be soft or absent if v big)
Loud pulmonary s2 (due to increased pulmonary arterial diastolic pressure)
Tachycardia, tachypneaand hepatomegally from heart failure
Investigations for large VSDs and what’s seen
CXR - cardiomegally, enlarged pulmonary markings and arteries, pulmonary oedema
ECG - biventricular hyper trophy by 2/12, pulmonary hypertension (tall T waves in V1)
Echo - demonstrates anatomy and can elicit haemodynamic effects and pulmonary HTN severity
Management of large VSD
Initial - management for heart failure and pulmonary hypertension.
Followed by surgery in cardiopulmonary bypass
What is done in infants with large VSD ? Why?
Pulmonary artery banding (band around PA to reduce flow / pressure)
Allows respite until child has grown enough to withstand definitive correction
When is a PDA physiological
Preterm infants
Where does the ductus come from ? What does it do!
Demand of 6 aortic arch.
Joins pulmonary artery and aorta (just after origin of left subclavian )
When does the PDA usually close
In first week of life
Clinical features of PDA
Continuous murmur beneath left clavicle
Increased pulse pressure (bounding pulse )
+ symtoms if duct is large (heart failure and breathlessness)
Investigations for PDA
CXR / ECG - usually normal
Echo - with Doppler
Management of PDA
High risk of bacterial endocarditis if left patent -> prostaglandin inhibitors (eg ibuprofen) in premature babies.
Surgery - if large at 1-3/12 if small at 1 year (in cardiac catheter lab)
Surgical methods in PDA
Division
Ligation or transvenous umbrella occlusion
Types of pulmonary stenosis
Valvular (90%), subvalvular (infundibular) or supra valvular
Which type of pulmonary stenosis occurs in tetralogy of fallot
Infundibular (with large VSD)
Symtoms of pulmonary stenosis
Most are asymtomatic
Signs of pulmonary stenosis
Ejection systolic murmur best heard at UPPER LEFT STERNAL EDGE (+thrill) accompanied by ‘ejection click’ in same area.
Widely spit s2 with a soft or absent p2
Investigations for pulmonary stenosis
CXR - normal (may have post stenotic dilatation)
ECG - evidence of R ventricular hyper trophy (UPRIGHT T WAVE IN V1)
Treatment of pulmonary stenosis
Trans catheter balloon dilatation
Types of coarctation ? Which is worse? Who gets more
Pre ductal (sick child) - interruption of aortic arch post ductal (asymtomatic ) Males 2x more
Features of pre ductal coarctation
Sick neonate with absent femoral pulses.
While ductus arteriosus is open the RV maintains cardiac output but after it closes -> HEART FAILURE
Treatment of pre ductal coarctation
Prostaglandin infusion to maintain ductal patency then transfer to cardiac surgery
Symtoms of post ductal coarctation
Usually asymtomatic - may get leg pains or headaches
Signs of post ductal coarctation
Hypertension in the right arm, radio femoral delay / absent femoral pulses
Opening click over aortic area (due to associated bicuspid aortic valve)
Sometimes ejection systolic murmur audible at L INTERSCAPULAR AREA
Investigations for post ductal coarctation
CXR - rib notching (due to development of large collaterals intercostal arteries running under ribs posteriorly (teens and adults))
- 3 sign (visible notch in descending aorta at site of coarctation)
ECG - LVH -> inverted T in v6, deep S in v2 and tall R in v6
Treatment of post ductal coarctation
Stenting by cardiac catheterisation
Surgical repair in severe cases
What needs to be determined in cyanosis
If it is peripheral (any cause eg sick, cold)
Or CENTRAL blueness of tongue and buccal mucosa which is associated with decrease in arterial oxygen tension
How do you clinically detect central cyanosis
Only possible if conc is >5g/dl (therefore less pronounced if child is anaemic)
Differentials for newborn with respiratory distress
Cardiac disorders - cyanotic CHDs
Respiratory disorders - surfactant deficiency, meconium aspiration, pulmonary hypoplasia …)
Persistent pulmonary hypertension of the newborn (PPHN)
Infection - septicaemia, group b strep…
Polycythaemia
Give the two main mechanisms for cyanosis in CHD
1- decreased pulmonary blood flow with shunting of deoxygenated blood from R->L (eg tetralogy of fallot)
2- abnormal mixing of systemic and pulmonary venous return usually associated with an increased pulmonary flow (eg transposition of the great arteries)
Diagnosis of CHD without echocardiography
Hyperoxia (nitrogen washout) test
(Measure arterial blood gas on air - then on 100% O2 ->
if lungs are healthy then will be no effect on ABG (R->L shunt likely)
If increased due to lung problem as O2 augments lungs ability)
What is the most common cause of cyanotic CHD
Tetralogy of fallot
What are the 4 features of tetralogy of fallot
Large VSD
Right ventricular outflow obstruction (50%infundibular stenosis,10%pulmonary valve stenosis, 30% both)
Aorta overriding ventricular septum
Right ventricular hyper trophy
Presentation of tetralogy of fallot
Cyanosis in first 1-2/12
Hyper cyanotic spells (due to infundibular spasm) and squatting on exercise
Physical signs of tetralogy of fallot
Cyanosis with /out clubbing
Loud and single s2 (A2 without p2)
Loud EJECTION SYSTOLIC MURMUR loudest at 3rd L ICS)
Tetralogy investigations and results (3 on X-ray)
CXR - usually normal. If child is older small heart (possibly with uptilted apex ‘boat sloped) due to RVH. Pulmonary artery ‘bay’ - con cavity on L heart border where convex shaped main pulm artery and RV outflow are normally profiled. Oligaemic blood flow (decreased pulm vascular markings.
ECG - Normal at birth. Then RVH & RIGHT AXIS DEVIATION (upright T wave in v1 and pure R wave (no S wave) )
Tetralogy hyper cyanotic spells management and reasons
Morphine - relieves pain and abolishes hyperpnea
Sodium bicarbonate IV - correct acidosis
Propranolol - cause peripheral vasoconstriction and relieve infundibular spasm
When is surgical treatment for tetralogy done ? What is done
BT SHUNT - between subclavian and pulm arteries (increased pulm blood flow
Patch closure of VSD and widening of R ventricular outflow tract
Who gets more TGA (transposition of great arteries)
Males 3x
What happens in a complete ‘D’ transposition?
What coexists
Aorta arises anteriorly from RV
Pulm artery arises posteriorly from LV
Defects that allow mixing of 2 circulations (ASD VSD PDA)
Features of TGA ? What is it unresponsive to ?
Severe cyanosis - often in first 1-2days of life
- usually when ductus closes which decreases mixing of systemic and pulm circulation
- arterial hypoxaemia often profound (1-3kPa PaO2) & unresponsive to O2 inhalation
Physical signs of TGA
Cyanosis always
Clubbing (if child presents after 1year)
Second heart sound is single and loud ( may be a murmur of VSD or PDA if septum is not intact)
Investigations for TGA and results
CXR - classically narrow upper mediastinum with an ‘egg on side’ appearance of cardiac show (due to anterior posterior relationship of great vessels and the hypertrophic RV
ECG - usually normal
What is given to sick cyanosed newborn with TGA
Prostaglandin E1 (PGE1) infusion to reopen ductus arteriosus
Management of TGA ?
How is a definitive repair completed
Pge1 infusion
Emergency cardiac catheterisation and therapeutic balloon atrial septosomy (rashkind procedure)
Repair with an arterial switch procedure in first few weeks of life
What is a septosomy
a small hole is created between the atria
What’s often heard during febrile illness / anaemia and why
Innocent murmurs due to increased cardiac output
Hallmarks of innocent murmurs
Asymtomatic
No parasternal thrill / radiation
No diastolic component
Localised to L sternal edge
2 egs of innocent murmurs
Soft blowing systolic - firm right pulmonary outflow in the 2nd L ICS )
Short buzzing murmur - from L side of heart due to aortic blood blow I’m 4th L ICS )
What is rheumatic fever
Sequela of group A B haemolytic strep infection (usually tonsilopharyngitis) caused by abnormal immune response in 1%
Leading cause of valvular disease
Rheumatic fever
When after infection does rheumatic fever develop
2-6/52
What are the features of rheumatic fever
Polyarthriris, fever and malaise Pan carditis (30%)
What is the arthritis like in rheumatic fever
Fleeting lasting 1-52 in individual joints and commonly affects large eg knees and ankles
What are the types of pancarditis in rheumatic fever
Pericarditis (friction rub and pericardial effusion) -> endocarditis which commonly affects L sided valves leading to murmurs eg. Mitral incompetence
Myocarditis - can lead to heart failure
What is a rare later effect of rheumatic fever
Sydenham’s chorea
6/12 later with emotional liability and chorea
How is the diagnosis of rheumatic fever made
Duckett-Jones criteria (2 major or 1M and 2m)
Treatment for rheumatic fever?
Acute? Severe? recurrent ?
Acute - bed rest and aspirin to relieve fever and arthritis
Steroids for sever carditis
Diuretics and ACEi for heart failure
Recurrent - prophylactic penicillin
When should children get prophylactic Abx
All with CHD (bar secundum ASD ) before any dental procedure / surgical treatment
When should you always ?endocarditis
Child with fever and significant heart murmur
Features of endocarditis
Bacteraemia (fever, malaise)
Valvulitis (HF, murmurs)
Immunological changes (gomerulonephritis)
Embolic changes (CNS abscess, sprinter haemorrhages )
Most common cause of endocarditis
Streptococcus viridans
Diagnosis of endocarditis
Blood cultures
Cross sectional Echo
Treatment of endocarditis
4-6 weeks high dose IV Abx +/- surgical removal of infected prostheses
Acute vs chronic features of myocarditis
Acute - cv collapse
Chronic - gradual onset congestive cardiac failure
Myocarditis treatment
Supportive - most recover but some have dilated cardiomyopathy
Infections associated with myocarditis
Coxsackie, rubella,
Normal arrythmia in children ? Why?
Sinus arrythmia - detectable change in HR with respiration (increase during inspiration and decrease during expiration)
What is the most common peadiatric arrythmia ? What is it ?
Supraventricular tachycardia - HR of 250-300
Features of supraventricular tachycardia
Most asymtomatic but some develop cardiac failure (and present with decreased feeding, sweating, irritability, sob)
Older children may describe palpitations
Diagnosis of supraventricular tachycardia
ECG shows narrow complex tachycardia with some p waves discernible after QRS due to retrograde action of atria via accessory pathway
When in sinus rhythm - decreased PR interval
What’s seen in wolf Parkinson white ECG
D wave and decreased PR interval
Treatment for supraventricular tachycardia
Vagal stimulation - cold water to face, carotid sinus massage, valsalva manoeuvre
IV ADENOSINE (if fails -> DC cardioversion (shock them) )
