Clinical history and current illness
22-year-old woman with a personal history of fibromyalgia, ex-smoker of 6-8 cigarettes a day and elective caesarean section the month prior to the current admission, with subsequent readmission for febrile syndrome secondary to possible infection of the surgical wound. Microbiological isolation of wound exudate was not obtained and she was discharged home. Fever persists associated with catarrhal symptoms of the upper respiratory tract, followed by progressive dyspnoea on exertion until she rested, chest pain with pleuritic characteristics and oedema in the lower limbs.

Physical examination:
- On admission, general condition was fair, tachypneic at rest and with slight jugular engorgement. - Blood pressure: 110/80 mmHg.
- No abnormal decrease in systolic pressure and pulse amplitude during inspiration (paradoxical pulse) was detected.
- Afebrile.
- Cardiorespiratory auscultation rhythmic, without murmurs, tachycardic at 140 beats per minute (bpm), good bilateral vesicular murmur with slight bibasal crackles and left basal hypophonesis.
- Abdomen soft and depressible, not painful on palpation and without visceromegaly.
- Lower limbs with slight pretibial oedema.
- The rest of the examination was unremarkable.

Complementary tests
- Electrocardiogram (ECG): sinus tachycardia at 146 bpm, low voltage and low R wave from V1 to V3.
- Laboratory tests: biochemistry with normal ions and renal function. Haemogram with normocytic anaemia, normochromic (haemoglobin 8 g/dl), slight lymphopenia. Coagulation normal.
- Chest X-ray: cardiomegaly, slight left pleural effusion.
- Transthoracic echocardiography: non-dilated left ventricle (LV) with end-diastolic diameter (EDD) of 42 mm, slight concentric hypertrophy (12-13 mm). Generalised hypokinesia with severely depressed ejection fraction (LVEF) less than 30% measured by Simpson method in apical four chambers. Mild mitral insufficiency. Moderate-severe pericardial effusion (PD), circumferential, 1.9 - 2 cm, predominantly inferior, posterior and lateral LV. Extension to the free wall of the right ventricle (RV) and right atrium (RA), with partial collapse. In the diaphragmatic face, a 1.3 cm chamber was observed. No respiratory variations in valvular flows. Inferior vena cava with a diameter of 20 mm, without inspiratory collapse.

Clinical evolution
Initially conservative management, with administration of serum therapy, transfusion of 2 red blood cell concentrates (the anaemia was initially related to the recent caesarean section) and oral non-steroidal anti-inflammatory drugs (NSAIDs). Elective pericardiocentesis was performed via the left parasternal route, draining 490 ml of serous fluid with biochemical characteristics of exudate and total debit of 790 ml. Low-dose beta-blockers and angiotensin-converting enzyme inhibitors were started, with good initial tolerance. Subsequently, he began with increased work of breathing and signs of pulmonary congestion, which led to the initiation of intravenous diuretics. Chest X-ray showed an increase in the amount of left pleural effusion, and diagnostic-therapeutic thoracentesis was performed, obtaining serous fluid. Poor clinical evolution, even initiating a pre-transplant study protocol. Control transthoracic echocardiography was performed, showing LV with severe systolic dysfunction (LVEF 20-25%), in addition to severe RV systolic dysfunction, tricuspid regurgitation (TR) grade II over IV and estimated pulmonary systolic pressure (PAPs) of 40 mmHg. Minimal PD. After a targeted re-examination of the patient, and faced with the need to make a differential diagnosis, she reported the appearance of skin lesions related to sun exposure over several years of evolution. This, together with the analytical data of normocytic normochromic anaemia, lymphopenia, febrile syndrome and pleuropericardial serositis, led us to suspect a possible outbreak of systemic lupus erythematosus (SLE) with myocardial involvement as the aetiology. After further laboratory tests, positive antinuclear antibodies (ANA), positive anti-DNA, hypocomplementemia, moderate levels of anticardiolipin antibodies, hypergammagrobulinaemia, elevated LDH and positive Coombs test (sign of haemolytic anaemia) were obtained, which led to a definitive diagnosis of a lupus outbreak with expression of pancarditis and severe biventricular systolic dysfunction.

Diagnosis
Lupus flare with expression of pancarditis, cardiac tamponade and severe biventricular systolic dysfunction.
