extra blood is displaced through a communication from the left to the right side of the heart, resulting in increased pulmonary blood ...
- extra blood is displaced through a communication from the left to the right side of the heart, resulting in increased pulmonary blood flow
- shunt volume dependent upon three factors: size of defect, pressure gradient between chambers or vessels, peripheral outflow resistance
- untreated shunts can result in pulmonary vascular disease, RVH, and R to L shunts
Atrial Septal Defect (ASD)
- Three types
- ostium primum - common in Down syndrome
- ostium secundum - most common type (50-70%)
- sinus venosus - defect located at entry of SVC into right atrium
- often asymptomatic in childhood
- Murmur:
- often grade 3-3/6 pulmonic outflow murmur with widely split and fixed S2
- ECG: RAD, mild RVH, RBBB
- CXR: increased pulmonary vasculature
- Natural history: 80-100% spontaneous closure rate if ASD diameter < 8 mm
- if remains patent, CHF and pulmonary HTN can develop in adult life
- Management: elective surgical or catheter closure (low risk procedures) between 2-5 years of age
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Ventricular Septal Defect (VSD)
- most common congenital heart defect (30-50%)
Small VSD (majority) (smaller than aortic valve,<3mm)
- asymptomatic, normal growth and development
- Murmur: early systolic to holosystolic, best heard at LLSB
- ECG and CXR are normal
- most close spontaneously, does not need surgical closure even if remains patent
Moderate to Large VSD
- Delayed growth and development, decreased exercise tolerance, recurrent URTIs or "asthma" episodes, CHF
- Murmur: holosystolic at LLSB with thrill, mid-diastolic rumble at apex
- ECG: LVH, LAH, RVH
- CXR: increased pulmonary vasculature, cardiomegaly, CHF
- Natural history: secondary pulmonary HTN, CHF by 2 months of age
- Management: treatment of CHF; surgical closure
Patent Ductus Arteriosus (PDA)
- patent vessel between descending aorta and pulmonary artery
- 5-10% of all congenital heart defects
- common in premature infants (1/3 of infants < 1750 grams)
- may be asymptomatic or have apneic or bradycardic spells, exertional dyspnea
- associated tachycardia, bounding pulses, hyperactive precordium,wide pulse pressure
- Murmur: continuous "machinery" murmur, best heard at left infraclavicular area
- ECG: may show LVH, RVH
- CXR: normal to mildly enlarged heart, increased pulmonary vasculature
- Diagnosis by echocardiography
- Natural history: spontaneous closure common in premature infants,
less common in term infants - Management: indomethacin, surgical ligation, or catheter closure
- high risk of SBE, antibiotic prophylaxis required until 6 months after closure
Endocardial Cushion Defect
- spectrum from endocardial cushion VSD and ostium primum ASD to
complete AV canal with common AV valve - commonly associated with Down syndrome
- natural history depends on size of defect and valvular involvement
- complete AV canal require early complete surgical repair, preferably
before 3 months of age
