SPIKE FLOW Endocardial Lead Safety and Performance Study

Inclusion Criteria: * Subject undergoing a surgical or an interventional procedure, requiring temporary cardiac pacing per investigator's medical judgment or subjects with bradycardia who are under evaluation to determine if the cause is transient or permanent; * Subject is at least 18 years of age; * Subject provides written informed consent to the study. Exclusion Criteria: * Subject has a co-existing temporary pacing or an implanted active permanent pacemaker or a cardiac defibrillator; * Subject in cardiogenic shock; * Subject is currently in atrial fibrillation; * Subject is pregnant or breastfeeding; * Subject had a stroke within 6 months prior to enrollment; * Subject has renal insufficiency with creatinine \>2 mg/dl; * Subject with known bleeding diathesis; * Subject with a history of deep vein thrombosis or pulmonary embolism within 6 months; * Subject with known tricuspid valve disease that may impede catheter advancement to and withdrawal from the right ventricle; * Subject with known intracardiac thrombus or vegetation on echocardiography; * Subject with significant neck abnormalities such that placement of a right and/or left internal jugular vein line would be difficult; * Subject has an active systemic infection or local infection at or around the insertion site; * Subject is involved in another clinical study that could influence the safety or outcome measures of this study.