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Year : 2022 | Volume
: 32
| Issue : 4 | Page : 230-232
A quadricuspid aortic valve with incomplete partitioning can mimic a tricuspid aortic valve
Solmaz Borjian, Reza Hali
Department of Cardiology, Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran
Correspondence Address:
Reza Hali
Department of Cardiology, Tehran Heart Center, Tehran University of Medical Sciences, Karegar Shomali Street, Tehran
Iran
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/jcecho.jcecho_45_22
A 67-year-old male candidate for coronary artery bypass graft surgery was referred to our echocardiography laboratory for preoperative evaluation. Transthoracic echocardiography showed left ventricular dilation with normal systolic function and an eccentric jet of severe aortic regurgitation with an aortic valve (AV) which mostly seemed to be tricuspid. Transesophageal echocardiography, later performed for better assessment of the mechanism of regurgitation, demonstrated a quadricuspid AV with an unusual incomplete cusp partitioning on the medial side with an appearance similar to a tricuspid AV on opening position. Abnormal juxtaposition of leaflets resulted in severe eccentric regurgitation, but no stenosis [Figure 1], [Figure 2], [Figure 3], [Figure 4]. The ascending aorta was also mildly dilated. He had no concomitant congenital anomaly and no history or any finding in favor of rheumatic fever or bacterial endocarditis. Coronary artery bypass graft surgery and AV replacement (St. Jude Medical mechanical valve) were later performed for the patient after comprehensive preoperative evaluation.
Figure 1: Transesophageal echocardiography, midesophageal window, 40° short-axis view of aortic valve in semi-open position in early systole showing quadricuspid pattern of aortic valve
Figure 2: Short-axis view of aortic valve in midesophageal window, 47° view of TEE. The appearance of AV mimics a normal tricuspid valve. AV = Aortic valve, TEE = Transesophageal echocardiography
Figure 3: Transesophageal echocardiography, midesophageal window, 40° short-axis view with better focus on aortic valve in open position showing incomplete partitioning of noncoronary cusp of AV or possible fusion and raphe between supernumerary and noncoronary cusps of an originally quadricuspid AV. AV = Aortic valve
Figure 4: Transesophageal echocardiography, midesophageal window, 140° long-axis view of aortic valve. Color Doppler image shows severe aortic regurgitationQuadricuspid AV is a rare congenital anomaly of AV. It was first reported in 1847, and the incidence rate reported to be 0.013%–0.043% in general population, but the actual incidence could be underreported due to rarity of the anomaly.[1],[2],[3] The age of clinical presentation is usually 4th–5th decades of life and is a little more prominent in male.[4],[5]
Embryology of quadricuspid AV is not clearly established, but some hypotheses have been proposed. During normal embryogenesis, two mesenchymal ridges form in the cephalad portion of the truncus arteriosus at the 5th week. These ridges fuse and descend into the ventricles and form the aorticopulmonary septum. Three mesenchymal swellings form at the junction of the conus and truncus, and each gives rise to each semilunar valve. Quadricuspid AV could be due to an abnormal proliferation of the cusps or a supernumerary variant of a primary aortic mesenchymal bud.[3],[6] Some studies performed in Syrian hamsters proposed that quadricuspid AV is the result of abnormal partitioning of one of the three mesenchymal ridges that give rise to three AV cushions of normal tricuspid AV.[7],[8]
Quadricuspid AV is often accompanied by other congenital anomalies and aortopathies, but could also present as an isolated disease of AV.[2] It can occasionally be asymptomatic and diagnosed as an incidental finding during cardiac imaging.[1] Long-term prognosis and survival are usually excellent, but about 20% to one half of patients with quadricuspid AV may need surgical intervention mainly due to severe AI or severe AS.[9] In symptomatic patients, aortic regurgitation is more common than aortic stenosis (90% vs. 8%) and may need surgical intervention with AV repair or replacement, usually in the fifth or sixth decades of life based on its type and class.[1],[10]
Despite common association with ascending aorta dilation in bicuspid AV s, it is rarely seen in quadricuspid AVs.[9] Of note, an AV with morphologic pattern of pseudo-quadricuspid can be presented due to septation of normal AV cusp secondary to pathologies such as rheumatic fever or bacterial endocarditis.[2]
Quadricuspid AV is classified into seven groups (A to G) in Hurwitz and Roberts' classification based on cusp size.[1] Nakamura classification is another classification method which defines four groups (I-IV) of quadricuspid AVs based on the position of forth cusp in relation to left coronary cusp, right coronary cusp or noncoronary cusp of AV.[2]
The unusual finding in this particular case of quadricuspid AV presented here that made it interesting to us was the prominent obvious raphe between two medial cusps (supernumerary cusp and noncoronary cusp) which made it difficult – at the first glance – to be distinguished from a normal tricuspid valve in opening position, especially on transthoracic echocardiography images. The correct terminology to be used to name this certain appearance of AV seems to be accompanied by some sort of ambiguity: is this condition better to be addressed as a quadricuspid AV with incomplete partitioning of a cusp during embryogenesis or a tricuspid AV with fusion and raphe between two primary cusps (supernumerary cusp and noncoronary cusp here)? A “quadricuspid AV with incomplete partitioning” or a “tricuspid AV with raphe?”
Declaration of patient consent
Authors certify that they have obtained appropriate patient consent form, and the patient has given in the form his/her consent for his/her images and other clinical information to be reported in the journal provided that his/her name will not be published.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
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