Introduction: One of the most common causes of mitral chordae rupture is a myxomatous valve disease (1, 2) that causes acute volume overload and progressive heart failure. We present a patient with severe volume overload due to massive mitral regurgitation and acute glomerulonephritis. The key issue was to determine the precipitating event and which condition should be treated first.

Case report: 60-year-old patient with known mitral valve prolapse (MVP) and mild mitral regurgitation (MR) presented himself in a local hospital as acute heart and renal failure. Two months prior hospitalization he had experienced intolerance to physical exertion, orthopnea, night sweats and fever up to 37.5 °C and has received antibiotics due to tonsillopharyngitis. At the time of admission, he was in functional NYHA IV status with acute nephritic syndrome that required intermittent hemodialysis. One week after, the patient was transferred to University Hospital Centre Zagreb in pulmonary edema, hemodynamically unstable, referred as a suspected endocarditis, although blood cultures were sterile. Three-dimensional transthoracic and transesophageal echocardiography revealed eccentric hypertrophy of the left ventricle with mild reduction of ejection fraction, left atrial enlargement (100ml), severe MR (regurgitant volume 65ml) from a ruptured chordae with complete inversion of the P1 (and prolapse of other segments). Vegetation as sign of endocarditis of the mitral were not found. Acute renal failure contributed to the volume overload of the left ventricle which caused a strain on the myxomatous mitral apparatus that primarily affected the chordae (Figure 1). Chordae rupture led to massive mitral regurgitation and acute heart failure. After initial stabilization, we tried to establish the cause of acute nephritic syndrome. Ultrasound examination of the kidneys found diffuse hyperechogenic thickening of the parenchyma. After serologic testing and renal biopsy, a rapidly progressive glomerulonephritis (GN) (pauci – immune cANCA positive) was diagnosed. Treatment included corticosteroid boluses, cyclophosphamide and plasmapheresis along with intermittent hemodialysis which significantly improved renal function so the patient was prepared for cardiac surgery. The patient underwent a mitral valve replacement with a mechanical valve. Postoperative period went uneventful, except paroxysmal atrial fibrillation successfully treated with electrocardioversion. Pathohistological analysis of the resected valve showed myxomatous degeneration without bacterial infiltration. A six months follow up revealed adequate patient recovery.

Conclusion: Acute glomerulonephritis progressed into renal failure, severe volume overload caused chordae rupture of the previously myxomatously altered mitral valve with a consequent development of the “circulus vitiosus”. In order to preserve the renal and cardiac function, glomerulonephritis was treated first and after stabilization, cardiac surgery was performed with an excellent recovery of the patient.