Parachute mitral valve

Abstract

An asymptomatic 30-year-old male was referred for a transthoracic echocardiogram because of a systolic murmur that was noted on a pre-employment physical exam. Transthoracic imaging demonstrated a single papillary muscle from which the chordae of both mitral valve leaflets were attached. The mitral valve was seen to have a parachute-like configuration. Given the benign nature of the presentation, the patient did not seek further investigation.

Beware Before Mitral Balloon Valvuloplasty: Parachute Mitral Valve Can Mimic Rheumatic Mitral Stenosis

“…The 2- and 3-dimensional transesophageal echocardiogram (Figure 1C) revealed moderate mitral inflow obstruction at the subvalvular level: a congenitally dysmorphic mitral valve with almost all of the chordae originating from the posteromedial papillary muscle with the anterolateral papillary muscle attached directly to the lateral commissure, with very short chordae consistent with a parachute-like mitral valve (Figure 1B through 1D). 1,2 A cardiac magnetic resonance imaging demonstrated the mitral valve chordae originated from the posteromedial papillary muscle (Figure 2A and 2B), a parachute mitral valve morphology variant. 3 A stress echocardiogram revealed no left ventricular (LV) ischemia but significantly worsened LV inflow obstruction (mean MV gradient increased from 6.5 to 25 mm Hg) and development of pulmonary hypertension with an increase in right ventricular systolic pressure from 30 mm Hg at rest to 60 mm Hg.…”

“…PMV and parachute-like MV (as in this patient) are congenital cardiac malformations in which there is defective delamination of the anterior and posterior parts of the trabecular ridge, the predecessor of the 2 papillary muscles, which creates a single papillary muscle. 1,2 There is either a single papillary muscle, usually the posteromedial, from which all chordae originate or one fully developed and 1 hypoplastic papillary muscle with shortened, thickened, and underdeveloped chordae. These deformities create a funnel configuration of the mitral valve that confers its parachute-like shape and LV inflow stenosis.…”

“…These deformities create a funnel configuration of the mitral valve that confers its parachute-like shape and LV inflow stenosis. [2][3][4] The PMV mimics an open parachute apparatus, as seen by multimodality imaging: the doming shape of the valve leaflets act as the parachute canopy, the chordae as the strings or suspension lines, and the papillary muscle as the risers and harness that attach to the rider. The combination of these abnormalities results in mitral inflow obstruction, which can mimic rheumatic MS.…”