Ann Thorac Surg 2004;78:1475-1476
© 2004 The Society of Thoracic Surgeons
Case report
HLHS With Severe Aortic Insufficiency in a Patient With 45,X/46,XY Mosaicism
Muhammad A. Mumtaz, MDa,*,
Roger B. B. Mee, MB, ChBa,
Athar Qureshi, MDb,
Chandrakant R. Patel, MDc,
Adel K. Younoszai, MDb
a Departments of Pediatric and Congenital Heart Surgery, The Cleveland Clinic Children's Hospital, Cleveland, Ohio, USA
b Pediatric Cardiology, The Cleveland Clinic Children's Hospital, Cleveland,, USA
c The Heart Center, Children's Hospital Medical Center of Akron, Akron, Ohio, USA
Accepted for publication July 10, 2003.
* Address reprint requests to Dr Mumtaz, The Cleveland Clinic Foundation, M-41, 9500 Euclid Ave, Cleveland, OH, USA 44122
mumtazm{at}ccf.org
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Abstract
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Aortic insufficiency is not a part of the hypoplastic left heart syndrome. This report describes a rare case of congenital aortic insufficiency from a detached leaflet in a patient with hypoplastic left heart syndrome and 45,X/46XY mosaicism. The patient was subsequently treated with the modified Norwood procedure along with suture closure of aortic valve.
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Introduction
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Hypoplastic left heart syndrome (HLHS) is characterized by hypoplasia of the left-sided cardiac structures, namely the mitral valve, left ventricle, aortic valve, ascending aorta, and aortic arch. The disease presents with a broad spectrum of anomalies. Mild cases may have mild hypoplasia of aortic valve and ascending aorta along with coarctation of aorta. In severe cases, the left ventricle may be slit-like with an ascending aorta diameter less than 2 mm and a severely hypoplastic arch. Aortic valvular insufficiency (AI) is typically not part of the complex. Treatment involves a complex repair named after William Norwood: the right ventricle is connected to the systemic circulation, followed by a staged Fontan-type repair. Neonatal heart transplantation is also performed as a primary therapy in some centers [1]. Despite advances in surgery, anesthesia, and critical care, mortality remains significant [2]. We present a case of HLHS with severe AI in a patient with 45,X/46,XY mosaicism. Although congenital heart disease has been reported in 45,X/46,XY mosaicism, the association is thought to be incidental [3].
A full-term baby with a prenatal diagnosis of HLHS and aortic regurgitation was born to a 35-year-old G2P1 mother. The mother had a history of bipolar disorder and insulin-dependent diabetes mellitus. Her only medication throughout pregnancy was doxepin, and she was never on lithium. During pregnancy, a chromosomal analysis on amniocentesis revealed 45,X/46,XY mosaicism. At birth the child was a phenotypic male with normal internal and external genitalia. Abdominal and cranial ultrasound were normal. A prostaglandin infusion was started after birth and the patient was intubated for worsening acidosis and poor systemic perfusion. Postnatal echocardiography confirmed HLHS with a nonfunctional small left ventricle. There was severe aortic regurgitation as well as mitral regurgitation (Fig 1). Continuous flow was traced from the ascending aorta into the noncontractile left ventricle, across the mitral valve into the left atrium, and across a nonrestrictive atrial septal defect to the right atrium (Fig 2). The aortic annulus was 6 mm and the ascending aorta was 5.3 mm. The diameter of the transverse aortic arch was 5.8 mm, and diameter of the isthmus was 3 mm. After stabilization, the baby underwent surgery at 2 days of age. During operation, the left coronary cusp of the trileaflet aortic valve was found to have detached from the annulus. The detached leaflet had slight greenish discoloration; however, no vegetations or other evidence of endocarditis was noted. The leaflets were sewn to close the aortic valve below the coronary ostia, and a modified Norwood procedure was performed. The patient did well postoperatively and was discharged on the 17th postoperative day. Recent transthoracic echocardiogram showed good systemic (right) ventricular function and no AI. The left ventricle is small, without any contractile function. There is no obstruction across the neoaorta and mitral regurgitation is decreased.
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Fig 1. AI and MR during systole. Arrows depict direction of regurgitant blood flow. (Ao = aorta; LA = left atrium; LV = left ventricle; RA = right atrium; RV = right ventricle.)
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Fig 2. Aortic regurgitation during diastole. Arrow depicts direction of regurgitant blood flow. (Ao = aorta; LA = left atrium; LV = left ventricle.)
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Comment
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A number of congenital heart defects can result in AI in neonates. However, such an association with HLHS is rare. Krasemann and associates [4] have reported a case of congenital AI associated with absent valve leaflets. In their patient, the mitral valve was stenotic. Aortic regurgitation can be seen in patients with Shone's complex after balloon angioplasty of the aortic valve or after surgical repair. In addition, neoaortic regurgitation can occur after the first stage of the Norwood operation. Aorto-left ventricular tunnel is another lesion with severe aortic regurgitation. However, the left ventricle is usually sufficiently developed to allow biventricular repair. Our patient is unique in that no previous procedure was done. The aortic valve was trileaflet. The aortic annulus was larger than typical with HLHS, which enabled access to repair the AI. Intrauterine infection could be a cause in our patient, as there was mild greenish staining of the detached leaflet. However, the leaflet tissue was well preserved, and no vegetations were seen. The AI complicated the pathophysiology by decreasing systemic and coronary perfusion. Our usual practice in HLHS is to wait 3 to 5 days before performing a modified Norwood procedure. This allows time for the pulmonary vascular resistance to decrease. However, with AI, we performed the procedure earlier because of evidence of decreased systemic perfusion and possible myocardial ischemia.
Of interest is the incidental presence of 45,X/46,XY mosaicism in our patient. In a series of 92 prenatally diagnosed patients with 45,X/46,XY mosaicism, Chang and associates reported only two cases of congenital heart disease [3]. In this series 95% of the cases were of male phenotype, as was the patient in this report.
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References
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- Razzouk AJ, Chinnock RE, Gundry SR, et al. Transplantation as a primary treatment for hypoplastic left heart syndrome: intermediate term results. Ann Thorac Surg. 1996;62:1–7[Abstract/Free Full Text]
- Gaynor JW, Mahle WT, Cohen MI, et al. Risk factors for mortality after Norwood procedure. Eur J Cardiothorac Surg. 2002;22:82–89[Abstract/Free Full Text]
- Chang HJ, Clark RD, Bachman H. The phenotype of 45,X/46,XY mosaicism: an analysis of 92 prenatally diagnosed cases. Am J Hum Genet. 1990;46:156–167[Medline]
- Krasemann T, Kehl HG, Hammel D, Asfour B. Congenital aortic regurgitation due to absent aortic cusps and high degree mitral stenosis. Pediatr Cardiol. 2003;24:304–306[Medline]
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Abstract
Introduction
