Systemic Lupus Erythematosus (SLE) is a multi-organ autoimmune disorder that may result in death due to cardiac dysfunction. This dysfunction often occurs due to an endocarditis, known as Libman-Sacks, which presents on heart valves. The condition is hard to clinically diagnose and is often observed postmortem. Heart damage has been observed in the NP-SLE Lewis rat model positive for SLE. However, research has not been done in this model on the correlation between SLE and Libman-Sacks endocarditis. Numbers of occurrence have ranged from 3-50% in SLE patients. The presence of Libman-Sacks endocarditis should likewise occur in 3-50% of NP-SLE Lewis rats. There will be seven NP-SLE Lewis rats, five negative serum control rats, and five saline injected control rats. By performing this controlled study in rats, the correlation between SLE and Libman-Sacks will be better understood. / Department of Physiology and Health Science