Mitral valve annuloplasty ring having a posterior bow

DETAILED DESCRIPTION The present invention provides an annuloplasty ring for implantation in a mitral valve annulus that has a pathologic condition such that the posterior aspect thereof droops downward abnormally.
The annuloplasty ring includes a rounded ring body having an anterior section and a posterior section.
The ring body is oriented about a central flow axis that defines an upward direction and a downward direction, the downward direction corresponding to the direction of blood flow through the mitral valve annulus.
The posterior section the ring body bows downward out of a plane perpendicular to the central flow axis.
The ring body may bow downward between about 2-15 mm from one end thereof to a lowest point, and desirably bows downward between about 4-8 mm from one end thereof to a lowest point.
The bow in the ring body may or may not be centered in the posterior section.
Preferably, the ring body is made of a malleable material such that the bow in the ring body may be manually reshaped.
Desirably, the ring body is made of a semi-rigid material that will retain its posterior bow in opposition to the stresses that will be imparted by muscles of the heart throughout each beating cycle.
The ring body may be substantially planar except in the posterior section, or an anterior section of the ring body may bow upward from one end thereof to a lowest point.
In plan view, as seen along the flow axis, the ring body preferably defines an oval shape with a major axis perpendicular to a minor axis, the minor axis bisecting both the anterior and posterior sections.
Further, the bow in the posterior section may begin at symmetric locations across the minor axis that are spaced from the major axis around the ring body by an angle .
theta.
of between about 0-45.
degree.
, more preferably about 30.
degree.
.
The ring body may further include two upward bows on either side of the downward bow on the posterior section, and wherein downward bow may be between about 2-15 mm.
In one embodiment, the ring body comprises a plurality of ring elements concentrically disposed