Unique echocardiographic features of mitral regurgitation associated with noncompaction of the ventricular myocardium.

Sir,

Noncompaction of the ventricular myocardium (NCVM) is a primary genetic cardiomyopathy.[1] We observed an association of NCVM with mitral valve deformity leading to mitral regurgitation (MR) before, where strict criteria were used, including the measurement of compacted to noncompacted layer thickness ratio of >2:1 and demonstration of intertrabecular recesses by color flow mapping.[23]

We recently found three patients (all females) with this association presenting with heart failure due to MR. Symptoms started at the age of 3-7 years. All patients had echocardiographic thickening and retraction of both mitral valve leaflets and a zig-zag appearance of anterior leaflet which coapted superior to the posterior leaflet [Figures 1 and 2]. Severe MR was seen in all patients. The left ventricle ejection fractions were 60-65%.

Figure 1

Four chamber view of patient no. 1 showing thickened retracted anterior mitral leaflet with zigzag deformity

Figure 2

Parasternal long axis view showing coaptation of anterior mitral leaflet Superior to the posterior leaflet with thickened mitral leaflets

The usual cause of MR in patients with NCVM is mitral valve annular dilatation due to myocardial dysfunction, however, ejection fraction was preserved in our patients. In addition, changes in the leaflets indicated a distinct pathology. Fibrotic and calcific changes were documented on histopathological examination in one of our previous patients as well as in a series of 14 patients reported by Burke.[24] These reports support our observations.

Distinction of this new association from rheumatic MR is particularly important especially in older patients. In rheumatic MR, the posterior mitral leaflet is usually retracted and tethered to the left ventricle posterior wall while the anterior leaflet is hypermobile (personal observations), findings not present in our patients.

NCVM can have significant implications on the surgical treatment of patients with MR. In our experience with seven patients with NCVM and congenital heart disease who underwent surgical repair or palliation five out of seven (71%) developed post operative complications.[5] In conclusion, we describe distinct echocardiographic features in three more cases with this new association: NCVM–MR that to the best of our knowledge have not been reported before except in our reports.[2]