Unicuspid Unicommissural Semilunar Valvular Stenoses:

Realtime3D-echocardiographic Images

Jagdish C. Mohan Deepak Tomar Chander Shekhar Bimalpreet Kaur ,Vipul Mohan

Department of Cardiology , Ridge Heart Centre , Sunder Lal JainHospital, Ashok Vihar –III , Delhi -52

During development, the  semilunar valve is formed from
three tubercles, which each develop a cusp and sinus of Valsalva.
Fusion of the cusps results in a unicuspid valve. Unicommissural
unicuspid valves have one lateral attachment and an eccentric orifice. Acommissural unicuspid valves have no lateral attachment to the great vessel and have a central orifice.

Congenital anomalies of the semilunar valves are rare and most often involve the presence of a bicuspid or unicuspid valve [1]. Apart from quadricuspid valves found in the setting of the common arterial trunk, quadricuspid semilunar valves are exceedingly uncommon, with the pulmonary valve being affected more frequently than the aortic valve [2]. When the pulmonary valve is involved, its abnormal architecture rarely alters the function of the valve and the anomaly often remains silent [1, 2]. In contrast, when the aortic valve is involved there appears to be a distinct risk for the development of  stenosis or regurgitation. The estimated incidence of unicuspid aortic valve is 0.02% (1-3). This report describes one young child with  unicuspid unicommissural pulmonary valvular stenosis and an adult with unicuspid unicommissural aortic valvular stenosis.

Figure 1:  2DE  lower parasternal short axis views in diastole ( upper panel ) and  during systole ( lower panel ). Lower panel shows eccentric pulmonary valve flow jet ( arrow ) with lateral narrow orifice.Upper panel shows co-aptation of the pulmonary valve leaflet.

Case #1 :
This was an 8-year old  asymptomatic  young  male  child who underwent echocardiography for a murmur detected on routine physical examination in school. There was a basal  3/6 ejection systolic murmur with no click and normally split second heart sound. 2D- echocardiographic examination showed  doming of the pulmonary valve with  an eccentric opening and a peak instantaneous systolic gradient of 36 mmHg ( Figure 1A and 1B) . Real-time 3D- echocardiographic pictures show a large single leaflet ( L ) in systole  and a single commissure seen in diastole ( Figure 2A and 2B).

Figure 2: Real-time 3D echocardiographic views of the pulmonary valve as seen from the right ventricular outflow tract . Upper panel in systole shows a single large oval leaflet ( L). The lower panel in diastole shows a single lateral commissure ( C).

Correspondence:Prof J.C. MohanA-51, Hauz KhasNew Delhi-110016 India
Email: jcmohan@vsnl.com

Figure 3:  2DE   Parasternal short axis views in diastole ( upper panel) and in systole ( lower panel). Single posterior raphe is visualized in diastole and a single circular leaflet with only posterolateral attachment

Case #2:  
This  23-year asymptomatic  young man was on follow-up for a basal ejection systolic murmur and with a label of bicuspid aortic valve since 1989 .Index echocardiographic examination was performed to rule out infective endocarditis as he was running fever of one week duration. After suspecting unicuspid aortic valve on 2D-echocardiographic examination ( Figure 3A and 3B), he underwent real-time 3DE examination . The pictures are shown below ( Figure  4A and 4B). In view of asymptomatic status , aortic valve area of 1.3 cm2 and mean gradient of 32 mmHg, it was decided to follow him medically.

Figure 4 : 3DE views as seen from the outflow .Upper panel shows single thickened leaflet with an eccentric lateral opening. Lower panel in diastole shows a single true raphe situated posteriorly.

References
1. Novaro GM, Mishra M, Griffin BP. Incidence and echocardiographic
features of congenital unicuspid aortic valve in an adult population. J Heart
Valve Dis 2003;12(6):674–678.
2. Roberts WC, Ko JM. Frequency by decades of unicuspid, bicuspid, and
tricuspid aortic valves in adults having isolated aortic valve replacement for
aortic stenosis, with or without associated aortic regurgitation. Circulation
2005;111(7):920–925.
3. Roberts WC, Ko JM. Clinical and morphologic features of the congenitally unicuspid acommissural stenotic and regurgitant aortic valve. Cardiology 2007;108(2):79–81