AtaCor Subcostal Temporary Extravascular Pacing III Study

Prior revisions of the study intended to evaluate multiple StealthTrac Leads (Models AC-1010, AC-1020, AC-2021 and AC-1030) to support the development of a future pivotal study. In the most recent revision of the study, an additional StealthTrac Lead (Model AC-1012) will be evaluated to support use in a larger pivotal study. This study is a feasibility study serving dual purposes: 1) to generate developmental clinical data in support of a subsequent pivotal clinical study and marketing application for temporary pacing (in patients that retain the lead for a maximum of 7 days); and 2) to obtain early data for future research related to longer-term use (in patients that retain the lead for a maximum of 14 days). Subjects undergoing a qualifying index procedure will have a Model AC-1012 StealthTrac Lead inserted, evaluated for a Maximum Lead Insertion Time prior to removal and a final post-removal follow-up 27-33 days after lead insertion. The following elements will change after the absence of AtaCor-related cardiac tamponade and no more than one (1) serious AtaCor-related pericardial effusion has been confirmed from the initial eight (8) experiences with the Model AC-1012 StealthTrac Lead, including insertion and removal procedures performed by multiple operators: * Maximum Lead Insertion Time will change from 7 to 14 Days * Follow-up will change from in-hospital follow-up only to allowing hospital discharge with the StealthTrac lead inserted, but capped and inactive after Day 2 provided in-person wound checks occur at least every 3 days * Echocardiography requirements will transition from 3 distinct days to procedure day and removal day only.