Small VSD's may produce loud murmurs and large VSD's may produce no murmur at all but will cause heart failure usually at 6+ weeks. Many smaller VSD's close without any treatment
- Abnormal shunt between LV and RV.
- Seen in 2/1000 live births so commonest congenital heart disease
- Size of defect and pulmonary pressures determine clinical picture
- Increased pulmonary flow can result in pulmonary hypertension which then reduces flow
- Can lead to Eisenmenger's syndrome and reversal of flow will lead to cyanosis
Structure - 4 types
- Perimembranous 70% of all VSD. usually small and lie below the aortic valve. May close spontaneously
- Muscular 10%: These too often close. May be multiple.
- Supracristal 5-8%: superior to crista supraventricularis within the RV outflow tract. Associated with aortic valve prolapse and progressive AR.
- Inlet defects: Seen in the posterior ventricular septum below tricuspid and mitral valves.
- Loud, harsh pansystolic murmur/thrill at the lower left sternal border
- Hyperdynamic LV apex beat, pulmonary oedema
- Poor weight gain, fatigue after feeding. Look for signs of endocarditis
- Eisenmenger's syndrome - murmur reduces, RV failure
- High risk of endocarditis so be vigilant
- RV hypertrophy with lift and Volume overloaded LV,
- Small VSDs create loud murmurs and Large VSDs create soft murmurs
- FBC: Raised WCC/ESR/CRP may suggest endocarditis. U&E and LFTS: usually normal
- CXR: normal with small VSD but cardiomegaly and enlarged Pulmonary arteries and increased vascular markings and possibly oedema
- ECG - normal if small otherwise RVH and LVH
- Echocardiography can anatomically place VSD and estimate pulmonary artery pressures
- Cardiac failure in infancy is managed with diuretics and Digoxin and ACE inhibitors
- Defects may close spontaneously during infancy
- The remainder may require surgical repair at 3-6 months
- Surgery is reserved for those who have a significant shunt before Eisenmenger's develops
- Endocarditis antibiotic prophylaxis is recommended as the risk of SBE
- Percutaneous closure with umbrella devices is still experimental
- Endocarditis, Heart failure, Arrhythmias