Download A case of hypoplastic left heart syndrome

Case Presentation : Hypoplastic Left Heart Syndrome (HLHS)
Dr.Ranjitha.G, Specialist Radiologist, NMC SH Al Ain, UAE
Incidence: HLHS occurs in approximately 1 in 10000 live births.
Definition: HLHS includes a spectrum of heterogeneous conditions characterized by severe hypoplasia of the left ventricle and left ventricular outflow tract.
Anatomy: There are two forms of HLHS: first one is characterized by mitral and aortic atresia, the second by aortic atresia and a hypoplastic but patent mitral valve . The other cardiac anomalies,
characterized by severe hypoplasia of left cardiac sections, that are unable to support systemic circulation , are also included under the term HLHS; and are represented by some forms of critical aortic
stenosis, by the Shone complex (which is characterized by anomalies of mitral valve, coarctation of aorta and sub aortic stenosis) and by unbalanced ASD with right ventricular dominance. Aortic coarctation
is associated with 70% of cases of HLHS.
Ultrasound diagnosis: On the 4-chamber view, either a small globular left ventricle with endocardial fibroelastosis or a slit-like left ventricle (mitral and aortic atresia) are detected. The hypoplastic left
ventricle never reaches the apex of the heart. The mitral valve is atretic or with a hypoplastic annulus. On the long axis view of the left ventricle it is possible to observe with difficulty a threadlike ascending
aorta and extremely hypoplastic annulus of the aortic valve. Color doppler confirms the absence of filling of left ventricle and demonstrates reverse flow (left to right) flow across the foramen ovale and mitral
regurgitation, in those characterized by patent and dysplastic mitral valve . On the 3 vessel view, color doppler demonstrates the retrograde flow in the hypoplastic aortic arch.
Case discussion: A pregnant women ( G2P1L1A0) who conceived after 8 years of secondary infertility came for a routine antenatal screening at 24 weeks of gestation. The cardiac abnormalities were in
favor of HLHS. The primary findings were hypoplastic left ventricle, aortic atresia and a hypoplastic but patent mitral valve. There were no other structural anomalies detected in the rest of the fetus. She was
referred to a tertiary care center where the diagnosis was confirmed. The parents were councelled and are expected to deliver in a tertiary set up in their native country. The couple had refused chromosomal
analysis.
Figure A
Figure B
Figure C
Figure A: Abnormal 4-chamber view with a
small, non apex–forming left ventricle.
Figure B: Long axis view of left ventricle
showing thin threadlike ascending aorta.
Figure C: 3 vessel view showing large
ductus arteriosus.
Figure D
Figure E
Figure F
Figure D: Color doppler flow in 4-chamber
view depicts patent mitral valve. The
turbulence across the mitral valve suggest
mitral regurgitation.
Figure E: Color doppler flow shows
retrograde flow in the hypoplastic aortic
arch.
.
Risk of chromosomal anomalies in HLHS: High (up to 15%) in the fetus; 3-4% in post natal life
Risk of non-chromosomal syndromes in HLHS : Low
Outcome in HLHS : Poor, with high postnatal mortality and morbidity.