Approval for the optisense model 1699t and 1699tc leads. the device, as modified, will be marketed under the trade name optisense model 1699t and 1699tc leads and are designed for permanent sensing and pacing in the right atrium, in combination with a compatible pulse generator. an active fixation lead such as the model 1699 may be indicated for patients where permanent fixation of passive leads is suspected to be unstable. in atrial applications, the use of a screw-in lead may be indicated in the presence of an abnormal, surgically altered or excised atrial appendage.