Left-right shunts- BREATHLESS

Question 1

List common left-right shunt CHDs

Answer 1

1. Ventricular septal defects
2. Atrial spetal defects
3. Persistent ductus arteriosus
4. Atrioventriculr septal defect (mixed)

Question 2

Anatomy and murmur characteristics of AVSD

Answer 2

• No murmur heard

Question 3

• Epidemiology
• Features
• Management of…

ATRIAL SEPTAL DEFECT

Answer 3

• ​Epidemiology
  
  • _​_7% CHDs
• Features
  
  • _​_Secundum: defect in centre of atrium - foramen ovale
  • Partial AVDS- defect of AV septum
    
    • primum ASD- interatrial connection between bottom end of atrium and atrioventricular valves
    • regurgitant valve- left AV valve that leaks
  • asymptomatic (common)
  • recurrent chest infection/ wheeze
  • arrhythmias- 40s+
  • signs: ejection systolic murmur (left sternal edge- increased flow over pulmonary valve due to left-right shunt), fixed and widely split 2nd heart sound or apical pansystolic murmur from AVSD from atrioventricular valve regurgitation
• Management
  
  • _​_large ASD–> right ventricular dilatation
  • secumdum ADS- cardiac catheter and occlusion device
  • partial AVSD- surgical correction
  • 3-5 yrs to prevent right sided heart failure and arrhythmias

Question 4

• Epidemiology
• Features
• Management of…

VENTRICULAR SEPTAL DEFECT

Answer 4

• Epidemiology
  
  • _​_30% CHDs
  • Common
• Features
  
  • ​Small VSDs: asymptomatic. Loud pansystolic murmur at lower left sternal edge. Quiet pulmonary 2nd sound (P2)
  • Large VSDs: HF +breathlessness and failure to thrive (1 week) and recurrent chest infections. Tachypnoea, tachycardia, hepatomegaly, active precordium, soft pansystolic murmur or no mumur (large defect) and apical mid-diastolic mumur (from increased flow across mitral valve after blood has circulated through lungs). Loud pulmonary second sound (P2)
• Management
  
  • ​Small VSDs: close spontaneously: disappearance of murmur, normal ECG, normal echo. Good dental hygiene
  • Large VSDs: diuretics, captopril, additional calorie input. Prevention of Eisenmenger’s syndrome perform surgery at 3-6 months (stop HF and pulmonary hypertension)

Question 5

• Epidemiology
• Features
• Management of…

PERSISTENT DUCTUS ARTERIOSIUS

Answer 5

Classification: defect in constrictor mechanism of duct. Not closed within 1 month of expected datee of delivery. Preterm birth many have PDA due to prematurity- not duee to CHD.

Epidemiology

• 12%

Features

• Continuous murmur beneath left clavicle
• Continues throughout diastole as pressure PA < aorta throughout cardiac cycle
• collapsing/ bounding pulse
• large duct = pulmonary HTN and HF

Management

• coil/ occlusion device introduced with cardiac catheter at 1 year
• prevention of bacterial endocarditis and pulmonary vascular disease

Question 6

Clinical features, ECG, CXR of AVSD

Answer 6

• Clinical features: DS, cyanosis at birth, breathless 2-3 weeks of life (mixed breathless and blue)
• ECG: superior axis
• CXR: cardiomegaly +/- features of pulmonary hypertension and mitral valve insufficiency.

Question 7

ECG, CXR and echo of VSD

Answer 7

• ECG: biventricular hypertrophy (by 2m), upright T wave = pul. HTN, inverted T wave= n pulmonary HTN
• CXR: cardiomegaly, enlarged pulmonary vessels, increased pulmonary vascular markings, pulmonary oedema
• ECHO: anatomy of defect confirmed, haemodynamic effects and pulmonary HTN

Question 8

ECG, CXR and echo of ASD

Answer 8

• ECG:
  
  • secundum: partial RBBB, right axis deviation (r.ven. hypertrophy)
  • partial: superior QRS axis- node conducts to ventricles superiorly
• CXR: cardiomegaly, enlarged pulmonary arteries, increased pulmonary avscular markings
• ECHO: delinate the anatomy