Structural heart disease Flashcards
Ductus arteriosus
Stops functioning within 1-3days of birth
Closes within first 2-3 weeks
If this fails = patent ductus arteriosus (PDA)
Causes/risk factors of PDA
Genetic
Maternal infections - rubella
Prematurity
PDA pathophysiology
Link b/ween aorta and pulmonary vessels
Blood: aorta to pulmonary vessels - L to R shunt
Pulmonary hypertension
R sided heart strain
R ventricular hypertrophy
L ventricular hypertrophy, as blood returns to L side of heart after pulmonary vessels
PDA presentation
SOB
Difficulty feeding (kids)
Poor weight gain (kids)
Lower respiratory tract infections
Heart failure
Asymptomatic
PDA murmur
Normal S1
Continuous crescendo to decrescendo machinery murmur - continues during S2
PDA diagnosis
Echo
Doppler flow used to assess left to right shunt
PDA management
Monitored till 1 year of age using echos if asymptomatic
Trans-catheter or surgical closure
Atrial septal defect definition
Hole in septum between two atria
ASD embryology
Walls of atria grow downwards from top of heart
Then fuse together with endocardial cushion in middle - separates the atria
Walls =septum primum and septum secondum
Septum secondum has hole called foramen ovale - normally closes at birth
ASD pathophysiology
ASD
Shunt - blood moves from RA to LA (higher pressure in RA)
Blood flows to pulmonary vessels - no cyanosis
R sided overload and heart strain
Right heart failure + pulmonary hypertension
Can lead to Eisenmenger syndrome
Types of ASD
Ostium secondum (septum secondum fails to fully close)
Patent foramen ovale (not strictly ASD)
Ostium primum (septum primum fails to fully close - atrioventricular septal defect)
ASD complications
Stroke if venous thromboembolism (DVT) - instead of travelling to lungs (PE) it can now travel to brain
AF/atrial flutter
Pulmonary hypertension/right sided heart failure
Eisenmenger syndrome
ASD murmur
Mid-systolic
Crescendo-decrescendo
Loudest at upper left sternal border
Fixed split S2 - aortic and pulmonary valves shut at slightly different times - does not change with inspiration/expiration (normal at inspiration)
ASD symptoms
SOB
Difficulty feeding
Poor weight gain
Lower respiratory tract infections
ASD managmeent
Refer to paeds cardiologist
Transvenous catheter closure via femoral vein
Open heart surgery
Anticoagulants in adults
Ventral septal defect definition
Congenital hole in ventricle septum
Entire septum or small hole
VSD associations
Down’s and Turner’s syndrome
Can occur in isolation
VSD pathophysiology
Blood flows from LV to RV
Remain acyanotic
Right sided overload, right heart vailure and pulmonary hypertension
Can cause Eisenmenber syndrome
VSD presentation
Initially symptomless
Poor feeding
Dysponea
Tachypnoea
Failure to thrive
VSD murmur
Pan-systolic
Left lower sternal border
3rd/4th ICS
Systolic thrill
VSD treatment
Paeds cardiologist
Transvenous catheter closure via femoral vein
Open heart surgery
Increased risk of IE - antibiotic prophylaxis
Eisenmenger syndrome causes
ASD
VSD
PDA
Eisenmenger syndrome timeline
develops after 1-2 years with large shunts or with small shunts in adulthood
More quickly in pregnancy
Eisenmenger syndrome pathophysiology
L to R shunt
Pulmonary hypertension
Pulmonary pressure > systemic pressure
R to L shunt
Blood bypasses lungs
Cyanosis
Cyanosis
Blue discolouration of skin due to low level of O2 sats
Bone marrow responds - produces more RBC and Hb
Polycythaemia (high Hb)
Plethoric complexion
Blood more viscous - blood clots
Eisenmenger syndrome signs
Pulmonary hypertension:
R ventricular heave - contracts forcefully against pressure
Loud S2
Raised JVP
Peripheral oedema
R-L shunt and hypoxia:
Cyanosis
Clubbing
SOB
Plethoric complextion (red)
Eisenmenger mortality
Reduce life expectancy of 20 years
Heart failure
Infection
Thromboembolism
Haemmorrhage
Increased in pregnancy
Eisenmenger management
Heart-lung transplant is only definitive treatment
Oxygen to manage symptoms
Sildenafil - pulmonary hypertension
Tx arrhythmias
Tx of polycythaemia with venesection
Anticoagulation
Prophylactic antibiotics
Coarctation of aorta pathophysiology
Narrowing of aortic arch, usually around ductus arteriosus
Linked with Turner’s syndrome
Reduced pressure of blood distal to narrowing
Increased pressure of blood proximal to narrowing (in heart and first three branches of aorta)
Coarctation of aorta presentation
High blood pressure in limbs supplied from proximal arteries
Low blood pressure in limbs supplied from distal arteries
Systolic murmur in left infraclavicular area and left scapula
Tachypnoea
SOB
Poor feeding
Grey/floppy baby
Left ventricular heave (hypertrophy)
Underdeveloped left arm / legs
Weak femoral pulses
Coarctation of aorta management
Prostaglandin E - keep ductus arteriosus open while waiting for surgery
Surgery to correct coarctation + ligate DA
Tetralogy of Fallot pathologies
VSD
Overriding aorta (entrance is further to right than normal - above VSD)
Pulmonary valve stenosis
RV hypertrophy
ToF pathophysiology
Deoxygenated blood enters aorta from RHS
- VSD allows mixing of blood
- Aorta in direction of travel of blood from RHS
- resistance of blood through pulmonary valve (stenosis)
R to L shunt - cyanosis
Increased strain of RV - R ventricular hypertrophy
ToF risk factors
Rubella
Increased age of mother
Alcohol consumption in pregnancy
Diabetic mother
ToF investigations
Echo
Doppler flow studies
CXR - boot shaped heart due to RV hypertrophy
ToF presentation
Ejection systolic murmur esp in pulmonary area
Cyanosis
Clubbing
Poor feeding
Poor weight gain
Tet spells
Tet spells pathophysiology
Intermittent symptomatic periods
R to L shunt worsened
Pulmonary vascular resistance increases / systematic resistance decreases
Physical exertion - generate CO2 - vasodilation - reduces systematic vascular resistance - increases R to L shunt
Tet spell presentation
Precipitated by waking, physical exertion or crying
Irritable, cyanotic and SOB
Reduced consciousness, seizures and death
Tet spell treatment
Squat/position with knees to chest - increase systemic resistance
Oxygen
Beta blockers - relax right ventricle
Iv fluids - increase preload
Morphine - decrease respiratory drive
Sodium bicarbonate - buffer metabolic acidosis
Phenylephrine infusion - increase systemic resistance
ToF management
Prostaglandin infusion in neonates - maintain ductus arteriosus
Total surgical repair by open heart surgery
Ebstein anomaly pathophysiology
Tricuspid valve set lower in RHS
Bigger RA and smaller RV
Poor flow to RV and pulmonary vessels
Associated with R to L shunt across ASD
Cyanosis
Associated with Wolff-Parkinson-White syndrome
Ebstein anomaly presentation
Heart failure
Gallop rhythm (S3 and S4)
Cyanosis
SOB
Tachypnoea
Poor feeding
Collapse / cardiac arrest
If ASD - presents after ductus arteriosus closes
Ebstein anomaly diagnosis
Echo
Ebstein anomaly management
Tx arrhythmias and heart failure
Prophylactic antibiotics
Surgical correction
Transposition of great arteries pathophysiology
Aorta and pulmonary trunk are swapped
Two separate circulations that don’t mix
Pregnancy - placenta does work for lungs
Life threatening at birth
Cyanosis
Need shunt to survive - PDA, ASD, VSD
Transposition of great arteries associated conditions
VSD
Coarctation of aorta
Pulmonary stenosis
Transposition of great arteries presentation
Cyanosis
Respiratory distress
Tachycardia
Poor feeding
Poor weight gain
Sweating
Transposition of great arteries managment
Prostaglandin infusion when neonate
Balloon septostomy - catheter into foramen ovale via umbillicus - create ASD
Open heart surgery - cardiopulmonary bypass machine performs arterial switch
