Valvuloplasty catheter

1. A method for dilating heart valve leaflets comprising:

providing a catheter having a balloon; said balloon having a proximal section and a distal section;

inflating said proximal and distal sections to a first pressure in which said distal section engages a ventricular outflow tract via direct, circumferential contact, while maintaining said proximal section in a non-fully expanded configuration;

positioning said distal section upstream and adjacent a valve annulus; said distal section having a larger diameter than a diameter of said valve annulus and said proximal section having a smaller diameter than said diameter of said valve annulus;

positioning said proximal section downstream and adjacent to said valve leaflets;

dilating said heart valve leaflets with said proximal section by further inflating said balloon to a second pressure higher than said first pressure.

2. The method of claim 1 , wherein said balloon further comprises a middle section located between said proximal section and said distal section;

and wherein said middle section expands to a fully inflated middle section diameter that is less than a distal section diameter of said distal section at said second pressure.

3. The method of claim 2 , wherein said middle section diameter is less than a proximal section diameter at said second pressure.

4. A method of dilating valve leaflets, comprising:

advancing a balloon to a valve;

inflating a distal section and a proximal section of said balloon to a first pressure lower than about 1 atmosphere so as to expand a diameter of said distal section of said balloon larger than a diameter of said proximal section of said balloon; said distal section of said balloon expanding into direct, circumferential contact with a ventricular outflow tract;

positioning said distal section of said balloon upstream of an annulus of said valve;

further inflating said balloon to a second pressure higher than about 1 atmosphere so as to expand said proximal section of said balloon against said leaflets of said valve.

5. The method of claim 4 , further comprising a waist section of said balloon, located between said proximal section and said distal section; wherein said waist section is positioned at said annulus of said valve prior to inflating said balloon to said second pressure.

6. The method of claim 5 , wherein said waist section is restrained from dilating said annulus of said valve.

7. The method of claim 5 , wherein said waist section expands to a size smaller than said distal section at said first pressure.

8. The method of claim 5 , wherein said waist section expands to a size smaller than said proximal section at said second pressure.

9. A method of dilating valve leaflets or a valve with a balloon having a proximal region, a middle region, and a distal region, comprising:

positioning said middle region of a balloon upstream of a valve annulus;

exposing said proximal region, said middle region, and said distal region to an inflation pressure and expanding said distal region of said balloon via said inflation pressure to a radial size larger than a diameter of said valve annulus and into direct circumferential contact with a ventricular outflow tract;

positioning said balloon such that said middle region is located at said valve annulus and said distal region is located upstream of said valve annulus;

expanding a proximal region of said balloon via further inflation of said balloon, so as to expand said valve leaflets.

10. The method of claim 9 , wherein material of said distal region is more compliant than said proximal region.

11. The method of claim 9 , further comprising restricting with a fiber reinforcement the diametric growth of said proximal region larger than an aortic root sinus of said valve.

12. The method of claim 9 , further comprising restricting with a fiber reinforcement the diametric growth of said middle region to be less than said valve annulus.

13. The method of claim 9 , wherein said distal region comprises a wall thickness less than said proximal region, so as to provide increased compliance of said distal region as compared with said proximal region.

14. The method of claim 1 , wherein said balloon is constructed of a membrane material comprising silicone, polyurethane, or a highly elastic polymer.

15. The method of claim 11 , wherein said fiber reinforcement comprises a woven, braided, or knit structure.

16. The method of claim 12 , wherein said fiber reinforcement comprises a woven, braided, or knit structure.

17. The method of claim 11 , wherein said fiber reinforcement comprises partially oriented yarns.

18. The method of claim 12 , wherein said fiber reinforcement comprises partially oriented yarns.

19. The method of claim 11 , wherein said fiber reinforcement comprises non-compliant yarns.

20. The method of claim 12 , wherein said fiber reinforcement comprises non-compliant yarns.

21. The method of claim 11 , wherein said fiber reinforcement comprises polyethylene terephthalate or nylon yarn.

22. The method of claim 12 , wherein said fiber reinforcement comprises polyethylene terephthalate or nylon yarn.

23. The method of claim 11 , wherein said fiber reinforcement is formed from elastic filaments that restrain expansion at low pressure and expand in a compliant manner thereafter.

24. The method of claim 12 , wherein said fiber reinforcement is formed from elastic filaments that restrain expansion at low pressure and expand in a compliant manner thereafter.

25. The method of claim 11 , wherein said fiber reinforcement is formed from a wrapped yarn comprising an elastic filament wrapped by a noncompliant yarn.

26. The method of claim 12 , wherein said fiber reinforcement is formed from a wrapped yarn comprising an elastic filament wrapped by a noncompliant yarn.