Cathie,
In the book, "60 Machine Quilting Patterns" by Pat Holly and Sue Nickels they show how to machine quilt a string of hearts. They make the top of the heart all the way across, and then come back and make the bottom half. Or, they make one side, and then come back up and make the other side.
The ISBN is 0-486-28013-6. If this book is still available, it has many wonderful patterns in it. The copyright is 1994.
Material MiMi