[Evaluation of hemolysis in 308 patients with valve prostheses. Practical value and causes of errors]

A study of haemolysis in 308 patients with prosthetic valves, making up a total of 364 prostheses, showed that the most practical test for screening patients is the level of the LDH 1 isoenzyme alpha-HBDH. After analysis of the lowest levels for each type of prosthesis currently in use, an acceptable average level for each is proposed. If the level of LDH 1 exceeds the limits of confidence, a complication must be excluded; this may be silent, and the most important is a dehiscence but a thrombosis or a deep haematoma must also be excluded. A periodic check on the enzyme levels should form part of the routine follow-up of these patients.