Clinical history and current disease
A 22-year-old Brazilian national who had been living in our country for 2 years, with a personal history of long-standing arterial hypertension treated with amlodipine, dyslipidaemia, tonsillitis resolved with antibiotherapy, mild bilateral hypoacusis of unknown aetiology and left thoracic herpes zoster. He had been diagnosed with chronic renal failure of unknown aetiology in another hospital for two years, when he had an episode of acute pulmonary oedema in the context of renal failure with glomerular filtration rate of 3 ml/min/1.73 m2, requiring urgent haemodialysis. A transthoracic echocardiogram was performed which showed normal cardiac cavities, left ventricle (LV) with eccentric hypertrophy and preserved biventricular systolic function. Since then, he has been on haemodialysis. He was referred to our centre a year ago to assess living donor renal transplantation. The echocardiogram performed as a pre-transplant protocol showed biventricular dilatation and severe dysfunction of both ventricles. On admission, intense cutaneous pallor, cutaneous-mucosal subictericia. Afebrile. BP 120/70 mmHg. There was an arteriovenous fistula with large debit in the right upper extremity. The patient reported usual functional class III/IV NYHA, with episodes of paroxysmal nocturnal dyspnoea, decubitus cough and orthopnoea in recent weeks. Given the haemodynamic situation of heart failure, he was admitted to our care for study. On auscultation, rhythmic tones at 90 bpm, with gallop and systolic murmur in mitral focus. Bilateral normoventilation. Hepatomegaly of 1-2 finger widths, painful on palpation. Malleolar oedema with fovea. No carotid murmurs. Signs of peripheral hypoperfusion.

Complementary tests
- Laboratory tests on admission: proBNP of 547,000 pg/ml, glomerular filtration rate of 18 mL/min/1.73 m2 and anaemia with haemoglobin of 10 g/dl and haematocrit of 30%.
- ECG: sinus rhythm with left ventricular enlargement and unspecific repolarisation alterations.
- Chest X-ray: severe cardiomegaly. Vascular redistribution and bilateral pleural effusion. - Serology: positive for hepatitis A virus, varicella-zoster, herpes simplex, cytomegalovirus and Ebstein-Barr virus.
- Transthoracic echocardiogram (TTE): showed severely dilated LV (end-diastolic diameter 73 mm), global hypocontractility with ejection fraction (LVEF) of 20%, cardiac output (CO) 3.67 L/min, elevated preload criteria. Right ventricle (RV) moderately dilated and frankly hypocontractile. Moderate mitral insufficiency (MI). Severe tricuspid insufficiency (TI). Dilated suprahepatic veins and inferior vena cava without inspiratory collapse. Systolic pulmonary artery pressure (PAP) of 45 mmHg. Severe pericardial effusion, with no evidence of haemodynamic compromise.
- Coronary angiography: coronary tree free of angiographically evident lesions.
- Ventriculography: severely dilated LV, LVEF 20% and end-diastolic pressure of 25 mmHg.
- Right catheterisation: mean right atrial pressure 11 mmHg, systolic PAP 50 mmHg and mean 37 mmHg. Cardiac output 6.42 L/min. Mean pulmonary capillary pressure 30 mmHg, with 'V' wave up to 45-50 mmHg.
- Thoracoabdominal CT: bilateral pleural effusion, pericardial effusion, ascites and stasis liver, all related to heart failure.

Clinical evolution
During admission to our department, daily haemodialysis sessions were started, with progressive improvement in his haemodynamic situation. The cardiological situation was re-evaluated and a slight left ventricular improvement was observed, but with persistent dilatation and severe RV dysfunction and no findings of specific aetiology. Therefore, the patient was proposed for cardiorenal transplantation, and after a favourable evolution, he was discharged. During follow-up, hypovolaemia with hypotension made it necessary to reduce the frequency of haemodialysis sessions to 6 days a week and to reduce pharmacological treatment.
He presented with a catarrhal episode with associated febrile syndrome, for which a chest X-ray was performed showing slight cardiomegaly, so a TTE was performed which showed a slight reduction in LV diameter with discrete improvement in systolic function. Six months after hospital discharge, he was readmitted as a transplant recipient and his initial evaluation showed a drastic reduction in radiological cardiomegaly since his last check-up, so a TTE was performed which showed significant improvement: LV with a DTD of 49 mm, global hypokinesia with LVEF of 30%, minimal TR allowing calculation of PAPs of 32 mmHg. In view of the findings, it was decided to perform an isolated renal transplant procedure, which took place without incident. During this admission, no inotropic drugs were required and there was no LV failure.
On discharge TTE, systolic function improved (LVEF 34%), with moderate concentric hypertrophy, CO 3.8 l/min and RV slightly dilated and normocontractile. At present, the patient is in NYHA functional class I. Subsequent follow-up showed progressive clinical improvement and improvement in echocardiographic parameters. Good nephrological evolution. At present, the patient is in functional class I NYHA. The last TTE 2 months ago showed a non-dilated and non-hypertrophied LV with excellent systolic (LVEF 71%) and diastolic function, normal RV in size and function, no MR, minimal TR with PAPs 25 mmHg and absence of pericardial effusion.

Diagnosis
- Cardiorenal syndrome
- Beneficial effect of renal transplantation on ventricular dysfunction
