Systemic lupus erythematosus (SLE) is an autoimmune disease involving various organ systems. However, some of these lupus manifestations are underreported but life-threatening, so these unusual presentations need to be documented. This study aims to report a case of sinus node dysfunction (SND) and acute transverse myelitis (ATM) as the initial presentation of SLE. A 55-year-old Filipina newly diagnosed with SLE initially presented with progressive left upper extremity weakness and numbness within two days. On admission, the patient was noted to have 3/5 left upper extremity weakness and progressive C4-C6 dermatome paresthesia. A computed tomography scan of the brain was negative for infarction or hemorrhage. However, on magnetic resonance imaging of the spine, an ill-defined focus of enhancement was noted from C1 to C4 and extensive edema extending from C1 to mid-C6 vertebra. ATM was considered; hence high dose of intravenous methylprednisolone was given for five days with a notable improvement in motor and sensory deficits. Patients within the same admission also developed an onset of atrial fibrillation in rapid ventricular response in the background of baseline sinus bradycardia with associated episodes of fatigue. SND, attributed to SLE, persisted despite steroids. Pacemaker insertion was done as definitive management. The patient was discharged with the improvement of motor strength to 4+/5 and with prednisone and hydroxychloroquine as discharge medications. In conclusion, recognition and documentation of SLE's rare but life-threatening presentations, such as SLE-ATM and SND, are essential to facilitate timely therapeutic management.