In some cases (best determined by yourself), it would be needed to delete a pulse. You can do so by going to your pulse overview on your profile.
First, browse to your profile using the "My Stats" button on the top right of the website. Then select the "Pulses" tab, about halfway through the page. You're now looking at a list of your pulses. Each pulse has a trashcan icon on the right-side of the entry, which you can use to delete that particular pulse. If you click it, you will get an overview of that pulse and you will need to confirm that you want to delete that pulse by entering your password.
If you're sure you've got the right pulse and want to confirm the deletion, enter your password in the designated input box and press enter.
Please keep in mind that this action cannot be undone, so be sure you've got the right pulse.