Cardiac disorders Flashcards
What are the features of an innocent heart murmur?
4S's: • aSymptomatic • left Sternal edge • Soft blowing murmur • Systolic only
Other:
• No added heart sounds
• No parasternal thrill
• No radiation
What are the causes of heart failure in children?
In first week of life = Left heart obstruction (e.g. coarctation of the aorta). Blood enters systemic circulation via patent ductus arteriosus, if this is closed, leads to acidosis, collapse and death
Causes in neonates:
• Critical aortic valve stenosis
• Coarctation of aorta
Causes in infants:
• ASD
• VSD
• Persistent PDA
Causes in adolescents:
• Eisenmenger syndrome (Right heart failure)
• Rheumatic disease
• Cardiomyopathy
What is Eisenmenger syndrome?
Left to right shunting
Increased pulmonary vascular pressure leads to endothelial dysfunction and vascular remodelling
Increased pulmonary vascular resistance
Reversal of shunt - Right to left shunting
Right sided heart failure
NOTE: This requires heart & lung transplant
Management is prevention of syndrome via correcting shunt and preventing pulmonary hypertension
What is the management of heart failure?
• Reduce preload ○ Diuretics (Reduce volume, so less ventricular filling) • Reduce afterload ○ ACE inhibitors • Enhance contractility ○ Dopamine ○ Digoxin • Improve oxygen delivery ○ Beta-blockers
What are the features of atrial septal defect?
Most common type is Secundum ASD which is a defect where the foramen ovale remains open. The second less common type is Partial AVSD, where there is a defect in the atrioventricular septum
Clinical features:
• None (Common)
• Recurrent chest infections/Wheeze
• Arrhythmias (From 4th decade)
• Ejection systolic murmur at left sternal edge
• Fixed and widely split second heart sound
Investigations: • CXR ○ Enlarged pulmonary arteries ○ Cardiomegaly • ECG ○ Partial RBBB ○ Right axis deviation • Echocardiogram ○ Mainstay of diagnosis
What is the management of atrial septal defect?
Only those with significant ASD will require treatment (Large enough to cause pulmonary vascular dilation)
Secundum ASD:
• Cardiac catheterisation
• Insertion of occlusive device
• “Percutaneous/Endovascular closure”
Partial AVSD:
• Surgical repair
Treatment occurs at 3-5 years of age
What are the clinical features of small ventricular septal defect?
• Defect smaller than aortic valve • Asymptomatic • LOUD pansystolic murmur lower left sternal edge ○ Smaller defects = Louder murmurs • Seen on echocardiogram • CXR/ECG normal • Closes spontaneously • Whilst open, must protect against bacterial endocarditis via good oral hygiene
What are the clinical features of large ventricular septal defect?
Defect larger than aortic valve
Signs/symptoms: • Breathlessness with heart failure • Faltering growth after 1 week • Recurrent chest infections • QUIET murmur ○ Larger defects = Quieter murmurs • Tachypnoea and tachycardia • Enlarged liver from heart failure
Investigations: • CXR ○ Enlarged pulmonary arteries ○ Cardiomegaly ○ Pulmonary oedema ○ Increased pulmonary vascular markings • ECG ○ Biventricular hypertrophy • Echocardiogram ○ Mainstay of diagnosis
What is the management of ventricular septal defect?
Small VSD = Will close spontaneously. Protect from endocarditis via good oral hygiene
Large VSD: • Diuretics/ACE inhibitors ○ To treat heart failure ○ Captopril • Surgery ○ Conducted at 3-6 months of age ○ Want to prevent pulmonary hypertension
What are the clinical features of persistently patent ductus arteriosus?
Defined as the failure of ductus arteriosus to close after 1 month of expected delivery date.
Commonly seen in preterm babies and is NOT the result of congenital abnormality. Most cases close spontaneously.
* Continuous "metallic" murmur below left clavicle * Asymptomatic * Increased pulse pressure
What is the management of patent ductus arteriosus?
In preterm infant = Indomethacin or Ibuprofen
In term infant = Occlusive device inserted via cardiac catheterisation at age of 1
NOTE: If a cyanotic disease is dependent on a PDA, DO NOT CLOSE THE PDA. Use prostaglandin analogues to keep it open for long enough to have surgery
What is the hyperoxia (Nitrogen washout) test?
A child is placed in 100% oxygen for 10 minutes.
Right radial arterial partial pressure is taken.
If O2 partial pressure remains low <15, then cyanotic heart disease can be diagnosed
What is the management of a cyanosed neonate?
- ABC approach
- Artificial ventilation
- Prostaglandin infusion to keep PDA open
What are the clinical features of tetralogy of fallot?
1) Subpulmonary stenosis leading to right ventricular outflow tract obstruction
2) Right ventricular hypertrophy
3) Large VSD
4) Overriding aorta over ventricular septum
This means that blood is shunted from right to left and travels from right ventricle to aorta, bypassing pulmonary system, leading to deoxygenated blood and hence, cyanosis.
Signs/Symptoms:
• Cyanosis from first week
• Squatting on exercise (improves blood flow to lungs)
• Loud, harsh systolic murmur at left sternal edge from day 1 (Due to pulmonary stenosis)
• Clubbing
Investigations: • CXR ○ Boot shaped heart ○ Small heart • ECG ○ Right ventricular hypertrophy in older children • Echocardiogram ○ Mainstay of diagnosis
Note: Commonly seen in DiGeorge Syndrome
What is the management of tetralogy of fallot?
Surgical repair of VSD and relief of pulmonary obstruction at 6 months
