Trileaflet Mitral Valve with Three Papillary Muscles Associated with Hypertrophic Cardiomyopathy: A Novel Case

Abstract

Congenital mitral valve (MV) malformations are uncommon, except for MV prolapse. Despite their infrequency, most of them are well-known and defined entities, such as congenital MV stenosis with two papillary muscles, parachute MV, supravalvular mitral ring, hypoplastic MV, isolated cleft in the anterior and/or posterior leaflets, and double-orifice MV. A trileaflet MV with three separate papillary muscles with concordant atrioventricular and ventricle-arterial connections is exceptionally rare. To the best of the authors' knowledge, it has been reported only once in association with subaortic valvular stenosis. We hereby describe a novel case associated with hypertrophic cardiomyopathy.

Case of trileaflet mitral valve: an important differential for non-classical intracavitary gradient in suspected hypertrophic cardiomyopathy

“…Although an association between HCM and trileaflet mitral valves has been described previously, in this case, the early diagnosis of HCM that later did not demonstrate progression of LV hypertrophy or increase in outflow gradient over 16 years was clearly a mischaracterisation of concurrent hypertensive cardiomyopathy with a complex, eccentric MR jet caused by the trileaflet mitral valve that was able to mascaraed as LV outflow obstruction on continuous wave Doppler(figures 1 and 7). 1 3–6 Interestingly, the patient’s first echocardiogram in 2002 was reported as an unusually significant LV outflow gradient given the minimal degree of LV hypertrophy. It is therefore important in cases of suspected HCM where there is a very high left ventricular outflow gradient in the presence of an eccentric MR jet that clinicians consider a differential diagnosis of a trileaflet mitral valve.…”

“…Although exceedingly rare, improvements in cardiac imaging technologies have led to the increasing characterisation of these congenital phenomena with now nine cases published globally to date 2. Of these cases, half describe an association with hypertrophic cardiomyopathy (HCM) 1 3–6. Only Guerreiro et al 7 address the prognostic implication of having trileaflet mitral valve by describing valve function over 10 years with deterioration to severe mitral regurgitation (MR).…”