A case of constrictive pericarditis with a milk of calcium pericardial effusion undergoing surgical treatment.

Milk of calcium (MOC) pericardial effusion (PE) is extremely rare and has rarely been reported. A 78-year-old man was referred to our institution because of breathlessness and bilateral leg edema. Echocardiography revealed mild PE. In addition, abrupt posterior motion of the ventricular septum in early diastole was observed. A non-contrast chest computed tomography revealed a hyperdense PE, with Hounsfield units of 130, suggestive of MOC PE. Right heart catheterization (RHC) revealed that the right ventricular pressure had a dip and plateau pattern. We diagnosed the patient with constrictive pericarditis (CP) with MOC PE. As the right heart failure secondary to CP was refractory to medical therapy, we decided to perform surgical treatment. During pericardiectomy, a highly viscous PE, of which the color was pale and reddish brown, was aspirated. Chemical analysis of the PE revealed a very high calcium content of 39.2 mmol/L. The clinical symptoms secondary to CP improved. RHC performed postoperatively confirmed the disappearance of a dip and plateau pattern in the right ventricular pressure. In conclusion, we experienced a of CP with MOC PE and surgical treatment contributed to the improvement of the clinical symptoms and pericardial constriction secondary to CP. Learning objective: Because constrictive pericarditis (CP) with milk of calcium (MOC) pericardial effusion (PE) can cause severe morbidity and even mortality, the early diagnosis of CP is important in patients suspected of having MOC PE. MOC PE has hyperdensity on computed tomography, so its findings could be helpful in the diagnosis of MOC PE. Pericardiectomy for CP with MOC PE may contribute to the improvement of the clinical symptoms and pericardial constriction secondary to CP.