Tri-leaflet mitral valve variant of hypertrophic obstructive cardiomyopathy: Comprehensive assessment with 3-D transesophageal echocardiography

Abstract

We report 2 cases of tri-leaflet mitral valve incidentally identified with perioperative transesophageal echocardiography (TEE) during surgical septal myectomy. 3-D TEE in both cases was crucial in confirming the diagnosis. A tri-leaflet mitral valve is an extremely rare finding. It has been associated with other congenital anomalies of the heart and is usually related to an anterior mitral leaflet cleft [1]. To our knowledge, this is the third case report in the literature [2,3] imaged with 3-D TEE illustrating three leaflets, with a distinct division arising at the region of the posterior scallop (P2) in the setting of HOCM. The first case is a 63 year old male patient with HOCM presented with gradual worsening dyspnea on exertion over 10 years. There was history of exercise-related syncope. The transthoracic echocardiogram (TTE) revealed significant LVOT obstruction with gradient of 106 mm Hg at rest and 127 mm Hg on Valsalva manoeuvre. There was moderate mitral regurgitation (grade 2/4 MR) at rest. The pre-pump TEE showed a tricuspid mitral valve with distinct anterior, medial and lateral leaflets. There was also a small partial small cleft at the tip of A2 scallop region. This was appreciated on 3-D imaging as well as from a deep trans-gastric view (see Fig. 1: Videos 1 and 2). The LVOT gradient was 7 mm Hg post-myectomy. There was a reduction in mitral regurgitation post-resection with residual MR arising from the A2 cleft.