Isolated cleft posterior mitral valve leaflet: an uncommon cause of mitral regurgitation

Prominent inter-scallop separations of the posterior leaflet of the mitral valve: an important cause of 'pathological' mitral regurgitation

The 2012 World Heart Federation (WHF) criteria for echocardiographic diagnosis of rheumatic heart disease (RHD) identify that the finding of 'pathological' mitral regurgitation (MR) in a screened individual increases the likelihood of detecting underlying RHD. Cases of isolated "pathological MR are thus identified as 'borderline RHD'. A large-scale echocardiographic screening program (Echo in Africa) in South Africa has identified that inter-scallop separations of the posterior mitral valve leaflet (PMVL) can give rise to 'pathological' MR. The authors propose that this finding when associated with isolated 'pathological' MR is unrelated to the rheumatic disease process. In this case report, we present two examples of 'pathological' MR related to inter-scallop separation from the Echo in Africa image database. We provide additional screening tips to accurately identify this entity.

The Trileaflet Mitral Valve

With the advent of 3-dimensional echocardiography, visualization of the mitral valve has greatly improved. Recently, there has been an increase in reporting of a distinct entity called the "trileaflet mitral valve" using 3-dimensional echocardiography. It is controversial whether this is a new entity or an improved visualization of isolated mitral valve clefts or trifoliate left atrioventricular valve in the setting of an atrioventricular septal defect (AVSD) with intact septum. We present a case of a trifoliate valve, interpreting our findings based on a systematic review of previous publication on trileaflet mitral valves, isolated clefts in the mural (posterior) leaflet of the mitral valve, and trifoliate left atrioventricular valves with AVSD and intact septal structures. We describe the latter entity as a left atrioventricular valve because it never achieves the features of a normal mitral valve. We compare the features of isolated clefts of the mural leaflet of the mitral valve with trifoliate left atrioventricular valve found in the setting of AVSDs with intact septal structures to illustrate the current controversy regarding these conditions. In conclusion, our review suggested the reported trileaflet left atrioventricular valves is likely a misnomer because of a lack of consideration of embryologic development and nomenclature, rather than a greater appreciation and identification of a new distinct disease entity.

Diagnosis of mitral valve cleft using real-time 3-dimensional echocardiography

BACKGROUND

Mitral valve cleft (MVC) is the most common cause of congenital mitral insufficiency, and MVC may occur alone or in association with other congenital heart lesions. Direct suture and valvuloplasty are the major and effective treatments for mitral regurgitation (MR) caused by MVC. Therefore, it is important to determine the location and magnitude of the pathological damage due to MVC when selecting a surgical procedure for treatment. This study explored the application value of transthoracic real-time 3-dimensional (3D) echocardiography (RT-3DE) in the diagnosis of MVC.

METHODS

From October 2012 to June 2016, 19 consecutive patients with MVC diagnosed by 2-dimensional (2D) echocardiography in our hospital were selected for this study. Full-volume RT-3DE was performed on all patients. The 3D-imaging data were cropped and rotated in 3 views (horizontal, sagittal, and coronal) with 6 directions to observe the position and shape of the MVC and the spatial position between the cleft and its surrounding structures. The maximum longitudinal diameter and the maximum width of the cleft were measured. The origin of the mitral regurgitant jet and the severity of MR were evaluated, and these RT-3DE data were compared with the intraoperative findings.

RESULTS

Of the 19 patients studied, 4 patients had isolated cleft mitral valve, and cleft mitral valves combined with other congenital heart lesions were detected in 15 patients. The clefts of 6 patients were located in the A2 segment, the clefts of 4 patients were located in the A1 segment, the clefts of 4 patients were located in the A3 segment, the clefts of 4 patients were located in the A2-A3 segment, and the cleft of 1 patient was located in the P2 segment. Regarding the shape of the cleft, 13 patients had V-shaped clefts, and the others had C- or S-shaped clefts. The severity of the MR at presentation was mild in 2 patients, moderate in 9 and severe in 8. Two of the patients with mild MR did not undergo surgery, while the remaining 17 patients did undergo surgery. Surgical treatment involved direct suture in 11 cases, reconstruction with ring annuloplasty in 3 cases and replacement in 3 cases. The diagnoses of MVC were confirmed by intraoperative findings. RT-3DE successfully captured full-volume 3D images of the 19 patients, which directly displayed the 3D structure of MVC with multiple views such as the position, shape, longitudinal diameter and width of the MVC, and the spatial position between the chordae tendineae surrounding the MVC and the aortic valve. The maximum longitudinal diameter of the valve leaflet cleft measured by RT-3DE and direct measurements during surgery were 12.02±2.12 and 13.01±2.45 mm, respectively, and the difference between these measurements was not statistically significant (P>0.05). Our results indicate that RT-3DE can provide more direct, accurate and abundant information.

CONCLUSIONS

RT-3DE is a simple and fast imaging technique, and the detailed 3D images obtained can be used to confirm the diagnosis of MVC. RT-3DE is considered to be an important preoperative test that provides more comprehensive information for selecting a subsequent procedure for treatment.

Successful mitral valve repair for severe mitral regurgitation caused by isolated cleft of the posterior leaflet

Cleft of the post mitral valve leaflet is extremely rare congenital cause of mitral regurgitation. Only six cases have being reported in literature. We report the case of a 34-year-old man with isolated cleft in the posterior mitral valve leaflet causing severe mitral regurgitation. The patient had been experiencing limitation of his exercise capacity becoming more easily tried. Therefore, he was referred for mitral valve surgery. The posterior mitral valve leaflet was successfully repaired using quadrangular resection technique. Intra-operative transesophageal echocardiography showed trivial mitral regurgitation after repair. Satisfactory clinical results were achieved at 2 years post-operatively.

Isolated cleft in the posterior mitral valve leaflet: a congenital form of mitral regurgitation

BACKGROUND

Isolated congenital cleft of the posterior leaflet of the mitral valve is a rare cause of mitral regurgitation (MR). This study describes the clinical, echocardiographic, and intraoperative findings as well as treatment options.

METHODS

Adults with an isolated cleft of the posterior mitral valve leaflet diagnosed by transthoracic echocardiography were evaluated with respect to clinical, echocardiographic, preoperative and intraoperative findings, and different surgical strategies.

RESULTS

The prevalence of isolated cleft of the posterior mitral valve leaflet in all patients examined was 0.11% (n = 22 out of 19 320 evaluated echocardiograms); male gender was predominant (73%). Dyspnea on exertion was present in almost all patients with at least moderate regurgitation. The predominant localization of the cleft was within segment P2 (59%), followed by a cleft between P1/P2 (18%). An isolated cleft in segment P3 or segment P1 occurred twice in each segment (n = 2; 9%) and between P2/P3 once (n = 1; 5%). Regurgitation was severe in 50% (n = 11), moderate in 9% (n = 2), mild in 27% (n = 6), and only trivial in 14% (n = 3) of the patients. Surgical treatment involved reconstruction with ring annuloplasty in 45% (n = 10) and replacement in 4.5% (n = 1). A total of 11 patients (50%) with mostly mild or trivial mitral regurgitation were treated medically only.

CONCLUSION

Two-dimensional high-resolution cross-sectional echocardiography allows the distinct diagnosis of a clefted posterior leaflet, whereas clinical presentation, electrocardiogram, chest x-ray, and angiography are failing to identify the correct etiology of MR in patients with isolated posterior leaflet cleft mitral valve (IPLCMV). Patients with moderate to severe MR were treated surgically with excellent outcome.