Never Too Old for a Congenital Heart Disease: A Case of a Unileaflet Mitral Valve in a 76-year-old Man.

Congenital malformation of the mitral valve is considered to be a rare and complex entity.1)2)

Singular leaflet mitral valve is the least prevalent form and has been mostly observed in infants, associated with symptomatic mitral regurgitation (MR) and tending to be incompatible with life beyond the neonatal period.1)2) We report herein an unusual cause of unileaflet mitral valve in a 76-year-old man who presented with 5-day history of dyspnea. His cardiac background comprises repair of atrial septal defect (ASD) and percutaneous coronary intervention. He had clinical signs of fluid overload and a pan-systolic murmur in keeping with MR.

Transthoracic echocardiography revealed moderate to severe MR due to coaptation deficit of unidentified etiology (Figure 1). Two and three-dimensional transesophageal echocardiography demonstrated elongated anterior mitral valve leaflet and hypoplastic posterior leaflet with shortened chordae (Figure 2, 3; Movie 1, Movie 2, Movie 3) causing prominent MR (Figure 4; Movie 4, Movie 5). The left and right ventricles were dilated with systolic impairment with elevated pulmonary systolic pressure.

Figure 1

Transthoracic echocardiogram in para-sternal long axis showing coaptation deficit of the mitral valve. LA: left atrium, LV: left ventricle.

Figure 2

Transesophageal echocardiography mid-esophageal view, 0°, showing the mitral valve with a rudimental posterior mitral leaflet adherent to the LV posterior wall (blue arrowhead) and elongated anterior mitral leaflet (red arrowhead). LA: left atrium, LV: left ventricle.

Figure 3

Three-dimensional short-axis view of the mitral valve showing hypoplastic posterior mitral valve leaflet (red arrowhead) and elongated myxomatous anterior mitral valve leaflet (AMVL).

Figure 4

Two-dimensional transesophageal echocardiography mid esophageal view showing showing the unileaflet mitral leaflet and color Doppler image of the mitral regurgitation.

The patient was stabilised on heart failure therapy and considered for mitral valve replacement.

Unileaflet mitral valves among adults are extremely rare and described mainly in case reports. In our case we propose that the congenital agenesis of posterior mitral leaflet and its functional importance has become apparent as a result of structural changes of the mitral anulus due to left ventricular dilatation secondary to ischemic heart disease.

Although, different forms of ASD could have genetic basis and are associated with anomalous pulmonary venous drainage or mitral valve cleft3); the link between ASD and unileaflet mitral valve has not been reported thus far.