Correspondence Address: Dr. B S Arun Department of Cardiology, Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bannergatta Road, Jayanagar-9th Block, Bengaluru - 560 069, Karnataka India
Source of Support: None, Conflict of Interest: None
Unicuspid aortic valve (UAV) is a rare congenital abnormality of the aortic valve. It usually presents with severe aortic stenosis (AS), necessitating surgical intervention. The diagnosis can be made with echocardiography. Hereby, we are reporting a case of a 23-year-old male who presented with exertional breathlessness and fatigue, due to severe AS, secondary to a unicommissural UAV, associated with mitral valve prolapse with severe mitral regurgitation.
How to cite this article: Katheria R, Bhat P, Arun B S, Nanjappa MC, Rao PS. An Unusual Association of Unicuspid Aortic Valve. J Indian Acad Echocardiogr Cardiovasc Imaging 2020;4:209-12
How to cite this URL: Katheria R, Bhat P, Arun B S, Nanjappa MC, Rao PS. An Unusual Association of Unicuspid Aortic Valve. J Indian Acad Echocardiogr Cardiovasc Imaging [serial online] 2020 [cited 2021 Dec 5];4:209-12. Available from: https://www.jiaecho.org/text.asp?2020/4/2/209/292633
Unicuspid aortic valve (UAV) is a rare form of congenital aortic valve malformation. Its prevalence in the adult population is 0.02%. However, in the patients undergoing surgery for aortic stenosis (AS), it is identified in 4%–5%. UAV is more common in males (male:female ratio = 4:1).
Two forms of UAV have been described: unicuspid unicommissural and unicuspid acommissural. They have been classified based on the presence or absence of a lateral attachment of the commissures to the aorta at the level of the orifice. Unicommissural UAV usually presents in the 3rd–5th decades, most often with isolated AS. The diagnosis can often be made with echocardiography. Definitive treatment is the surgical replacement of the valve, performed when significant AS or aortic regurgitation (AR) develops.
A 23-year-old male presented with complaints of dyspnea, palpitation, and easy fatigability of NYHA class III, from 1 year. The patient also noticed intermittent pedal edema during the past 6 months. On examination, the patient had tachycardia, with a heart rate of 112/min. Blood pressure was 100/70 mmHg. Jugular venous pressure was elevated. The apical impulse was in the left sixth intercostals space along the anterior axillary line with the hyperdynamic character. P2 was loud. Pansystolic murmur of grade 4/6 was present at the apex, and the ejection systolic murmur of grade 3/6 was present at the right second intercostal space.
On chest skiagram, he was found to have cardiomegaly with the left ventricular type of apex [Figure 1].
Transthoracic echocardiography (TTE) showed unicuspid unicommissural aortic valve with systolic doming. Gradient across the aortic valve was 73/47 mmHg. Aortic valve orifice area (AVOA) was 0.7 cm2. Indexed AVOA was 0.43 cm2/m2. Trivial AR was present. The aortic annulus was 18 mm. The ascending aorta was 35 mm [Figure 3]a and [Figure 3]b.
Figure 3: (a) Two dimensional parasternal short axis view showing unicuspid unicommissural aortic valve, (b) continuous wave Doppler across aortic valve showing severe aortic stenosis, (c) two dimensional parasternal long axis view showing bileaflet mitral valve prolapse with eccentric jet severe mitral regurgitation, (d) two dimensional apical 4 chamber view showing eccentric jet severe mitral regurgitation. LA: Left atrium, LV: Left ventricle, RA: Right atrium, RV: Right ventricle, RVOT: Right ventricular outflow tract
Severe eccentric jet mitral regurgitation (MR), directed toward interatrial septum (IAS) was noted. Myxomatous degeneration of mitral valve with bileaflet prolapse involving A1, P2 scallops was the mechanism of MR [Figure 3]c and [Figure 3]d. The left atrium was markedly dilated with dimensions of 9.7 cm × 7.6 cm, and there was aneurysmal bulging of IAS toward the right atrium. There was mild tricuspid regurgitation, with right ventricular systolic pressure of 40 mm Hg. Right ventricular dysfunction was present. Mild LVH was present. The left ventricular ejection fraction was 55% [Videos 1-5].
Three-dimensional (3D)-TTE was done which showed UAV [Figure 4], Videos 6 and 7].
He underwent surgical repair of the aortic valve, with the Ozaki procedure (Aortic valve repair using the autologous pericardial patch) along with mitral valve repair. Diagnosis of unicuspid, unicommissural aortic valve with mitral valve prolapse (MVP) was confirmed intraoperatively [Figure 5].
UAV was first reported in 1958 by Edwards. The normal trileaflet aortic valve consists of three cusps with three associated commissures. It develops from embryonic tubercules of the aortic trunk. UAV develops if there is a failure of separation of three aortic cusps before birth, which occurs because of incomplete separation of valve tissue during the first trimester of fetal life.
Acommissural UAV valve has no commissures or lateral attachments to the aorta at the level of orifice and appears as a pinhole on imaging. This type of UAV is associated with hemodynamic compromise during the neonatal period and often requires urgent intervention. On the other hand, unicommissural UAV has one lateral commissural attachment to the aorta at the level of orifice and in its morphology, appears as a slit-shaped structure. The preserved commissure typically lies between the left and noncoronary cusps and arises due to the persistence of the interleaflet triangle abutting the aorto-mitral curtain. This leads to a posteriorly directed slit-like opening that points toward the aortic valve., This formation of unicommissural UAV is the most commonly seen UAV in adults. Because the orifice in unicommissural UAV is larger than that in acommissural UAV, these patients typically present late in the 3rd–5th decades of life., Patients with UAV present with symptomatic AS about 20–30 years earlier, than do patients with the normal trileaflet aortic valve.
The diagnosis of UAV can be made with two-dimensional (2D) or 3D-TTE or Transesophageal echocardiography (TEE), cardiac computed tomography (CT), or cardiac magnetic resonance imaging., Echocardiographic diagnosis of UAVs is challenging. The rate of determination of UAV by TTE is about 15% to 25%. It increases to 70% to 75% with a specificity of 86% when intraoperative TEE is added. 3D-TEE enhances the accuracy of the diagnosis of UAV, as it provides real-time three-dimensional orientation.
The valve is most often misdiagnosed as the bicuspid aortic valve. This is because of heavy calcification, and 2D imaging of 3D aortic root limits the ability to distinguish between true zones of apposition and raphe in a short-axis view during diastole.
Heavy calcification also limits the diagnosis of UAV using alternative imaging techniques, like CT, which is further hindered by relatively low temporal resolution. Surprisingly, heavy calcifications may even fool the eye, on direct visualization of the valve.
Unicommissural UAV is best imaged in TTE during systole because the absence of cuspal separation during aortic valve opening in systole results in an eccentric “teardrop” opening.
Other abnormalities associated with UAV include AR, aortic aneurysm, coarctation of the aorta, aortic dilatation, aortic dissection, and patent ductus arteriosus. The most common of the valvular abnormalities associated with UAV is isolated AS. In our case, UAV was associated with MVP, which has not been reported in the literature.
The preoperative diagnosis of UAV is important, as it helps in planning the appropriate surgical procedure. UAV repair usually requires reconstruction plasty. In our patient, the Ozaki procedure was performed, which involves the replacement of individual valvular leaflet with autologous pericardial patches. This tends to mimic the anatomy of the normal aortic valve. The estimated 5-year-survival with valve repair is 88%.
Unicommissural UAV is a challenging diagnosis, despite using multimodality imaging techniques. However, echocardiography has a vital role in the identification, further characterization, and management of the UAV. 3D-imaging and TEE further support the diagnosis and increases sensitivity. Final confirmation is only intraoperatively on careful direct visualization.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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