Bake the pastry shells according to the instructions on the package.
Bring a large pot of water to a boil.
Add the shrimp and bring back to a boil, cooking until firm and pink, about 3 minutes.
Drain and cool.
In a small mixing bowl, combine the mayonnaise, cream, Worcestershire sauce and ketchup, stirring well to blend.
Fold in the shrimp.
Place the pastry shells on a serving platter and fill with the shrimp mixture.
Garnish the platter with parsley sprigs and lemon wedges.