BACKGROUNDPulmonary arterial hypertension (PAH) is a rare and severe complication of SLE, with a worse prognosis and poor survival with estimated prevalence 0.5-17.5%. Divided in two cluster: vasculitic when acute associated to other systemic manifestations or vasculopathic when chronic and in isolated form. Lupus myocarditis is also a rare and severe manifestation. Both require rapid clinical suspicion, diagnosis and aggressive immunosuppressive treatment. CASE REPORTA 29-year-old female was initially evaluated in the emergency department describing oligoarthralgia of small joints, fatigue, loss weight of 26 kg in 5 months. Worsening of the symptoms in the last 4 days with facial swelling, malar rash and erythematous plaques on face and neck, oral ulcers and daily fever. At physical exam: recurrent bradycardia, but normal vital signs. The patient had previous diagnose of fibrous dysplasia in facial bones, and facial computed tomography (CT) scan demonstrated periorbital cellulitis and broad-spectrum antibiotics were initiated. Cardiomegaly in chest X-ray. Transthoracic echocardiogram with pericardiac effusion, moderated mitral insufficiency, mid-apical dyskinesia, right ventricular failure (30%), preserved left ventricular function. Estimated pulmonary arterial systolic of 43 mmHg. Chest CT angiography excluded pulmonary embolism and interstitial lung disease. In the meantime, immune panel was compatible is SLE with ANA 1/640 quasi-homogeneous pattern, anti-DNA antibodies positive (38.4), anti-RNP and IgM anticardiolipin in high titles, low c3 and c4 complement levels-and also elevated natriuretic peptide (1,090 pg/mL). Initiated intravenous methylprednisolone 1 g for 3 consecutive days and cyclophosphamide mensal pulse (0.5 g/m²/month) by 6 months followed prednisone 1 mg/kg/day (tapering 10 mg/month) plus hydroxychloroquine 5 mg/kg/day. CONCLUSIONAlthough the patient didn't present dyspnea and edema, fever, weight loss, bradycardia and cardiomegaly, the X-ray led us to clinical suspicion confirmed by echocardiogram. We describe a rare and severe case of vasculitic cluster of SLE-PAH associated to myocarditis and severe right ventricular failure. Rapid recognition and treatment were important for therapeutic success.