Cardio - 2 Flashcards
Which are the duct-dependent lesions?
Coarctation of the aorta
Tetralogy of Fallot
Pulmonary stenosis, atresia
Tricuspid atresia
CYANOTIC:
Hypoplasic left heart syndrome
Transposition of great arteries
Death if duct closes!
What is the immediate management of a closing duct in a duct-dependent lesion?
Withhold high concentration of inspired oxygen
Administer iv Prostaglandin E2 (opens duct)
Maintain ABC
What are the presenting features of coarctation of the aorta?
Depends on anatomical site. Usually where the ductus arteriosus inserts - when it constricts to close, aorta may become constricted. Thus, it usually presents on day 2 with acute circulatory collapse.
Sick baby. Heart failure (pale, sweaty, irritable, SOB).
Absent femorals.
Lower extremity cyanosis (when duct still patent)
Severe metabolic acidosis
Weak/unequal pulses or BP
Duct-dependent lesion in neonatal period-
HTN in older child.
Ejection-systolic murmur between shoulder blades
What are the CXR and ECG findings in coarctation of the aorta?
CXR - cardiomegaly from HF and shock
ECG - normal
Diagnosis made with echo usually, which can also show other anatomical defects (such as concurrent bicuspid AV)
Which syndrome is coarctation of the aorta highly associated with?
Turner syndrome (45XO)
What is the management of coarctation of the aorta?
Balloon angioplasty (via cardiac catheter) Sometimes stent
Surgery - remove the narrow part of the aorta and reconstruct or patch.
Often, HTN remains and medication + cardiologist follow up needed
Which CHDs is coarctation of the aorta associated with?
Bicuspid aortic valve
What is venous hum?
Normal phenomenon in up to 20% of children.
Best heard just above right clavicle, radiates into neck. Continuous and constant.
Can typically be obliterated by brief digital pressure on the ipsilateral internal jugular vein.
What are the possible causes for heart failure which need to be eliminated and treated?
Sepsis + other systemic disease Electrolyte imbalance (eg. hypocalcaemia)
What are the general measures taken in paediatric heart failure?
Nutritional support in infants (150kcal/kg/d)
Children/adolescents 25-30kcal/kg/day
High protein (aa essential), low fat, low carbs
If acyanotic, O2 when sats < 90%
If cyanotic, O2 is not indicated (has no effect)
Reduction of salt intake if fluid retention. Reduction of fluid intake if edema or unresponsive to diuretic therapy or hyponatraemia
What is the medical management of paediatric heart failure?
Diuretics - reduce systemic, pulmonary and venous congestion. Spironolactone very good. Furosemide.
Needs monitoring of electrolytes!
ACE inhibitors - prevent pathophysiological cardiac remodelling/reverse. Also decrease afterload.
Start low-dose and titrate up while monitoring BP, renal function, and serum Potassium
Beta-blockers - low dose in stable patients (titrate up)
Digoxin (ionotrope) in ventricular dysfunction. Reserved for severe reduction in cardiac output.
Signs of cardiac failure
Faltering growth Tachypnoea Tachycardia Heart murmur, gallop rhythm Cardiomegaly Hepatomegaly Cool peripheries
Symptoms of cardiac failure
Breathlessness, particularly on feeding or exertion
Sweating
Poor feeding
Recurrent chest infections
Examination of a child with cardiac symptoms
Cyanosis
Clubbing
Pulse (rate, rhythm character)
BP
Cap refill
Inspection (distress, pre-cordial bulge, scars, ventricular pulse)
Palpation (thrill, apex beat, RV heave)
Auscultation (apex, LLSE, ULSE, URSE) and back (murmurs, loud heart sounds, splitting of heart sounds)
Hepatomegaly
Lung bases
FEMORAL pulses
Causes of HF in neonates
Duct-dependent circulation:
Hypoplastic left heart syndrome
Severe coarctation of the aorta
Critical aortic valve stenosis
Causes of HF in infants
High pulmonary blood flow:
VSD
AVSD
Large PDA
Causes of HF in older children
R or L HF
Eisenmenger syndrome
Rheumatic heart disease
Cardiomyopathy
What is usually the cause of HF in the 1st week of life
Left heart obstruction (coarctation of the aorta)
What is usually the cause of HF after the 1st week of life
L-to-R shunt
Decreasing pulmonary vascular resistance keeps increasing L-to-R shunt and thus pulmonary blood flow (pulmonary oedema and breathlessness)
Initial management of child with cardiac failure
Treat underlying cause
Bed-rest in semi-upright position Supplemental O2 (unless L-to-R shunt) Diet Diuretics and ACIE in L-to-R shunt Beta blockers and digoxin may help
Prostaglandin infusion if duct-dependent lesion
Features of pathologic murmurs
All diastolic and pansystolic
Late systolic
Loud murmurs (3/6)
Continuous murmurs
if abnormal s&s:
SOB, tiredness, failure to thrive, caynosis, clubbing, hepatomegaly
Characteristics of innocent heart murmurs
Systolic Short duration Low intensity Intensifies with exercise/fever May change with posture/head position No thrill/heave No radiation Asymptomatic patient
Left sternal edge
What are the types of innocent murmurs
Venous hum Flow murmur (short, systolic, often in fever) Musical murmur (systolic, LLSE)
Features of venous hum
Common and harmless
Above right clavicle and over right jugular (flow of blood causes vein wall to vibrate)
Hum is heard throughout the cardiac cycle
If finger on jugular, sound stops
Sound may disappear in supine position
