The ornamental design for a heart shaped pedal, as shown and described.
FIG. 1 is a front perspective view of my new, original and ornamental design;
FIG. 2 is a front view thereof;
FIG. 3 is a right side view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The dashed lines of the heart shaped pedal represent the bounds of the claimed design and form no part of the claimed design. Additionally, the unshown portion of the heart shaped pedal forms no part of the claimed design.