Long-term follow-up of mitral valve prolapse and latent tetany. Preliminary data.

The association between idiopathic mitral valve prolapse (MVP) and latent tetany (LT) is common, as shown in our previous studies on adults and children. On the basis of our experience with the effects of magnesium salts and/or beta-blockers on the symptoms of such patients, we tried to determine whether this therapy could also modify the left ventricular hyperkinesia (LVH) constantly associated with MVP. After showing the failure of short-term therapy (1-3 months), we found 12 cases treated for more than 1 year, having MVP, LVH and LT. The mean duration of this continuous therapy was 36.5 months (range 12-72 months). 5 men and 7 women (mean age 49; range 28-70) received magnesium salts (pyrrolidone carboxylate 4.5 g/day, lactate 3 g/day) either alone (2 cases) or associated with a beta-blocker (atenolol 100 mg/day, acebutolol 200-400 mg/day, propranolol, 40-160 mg/day; 10 cases). The erythrocyte magnesium was measured before, during and after therapy. All these 12 patients had repeat echocardiography at the end of the treatment. MVP was still present, as was LVH, in 50% of them. Mean erythrocyte magnesium was below the normal range before therapy (43 +/- 6.3 mg/l) and in the normal range after therapy (50.8 +/- 7 mg/l). But no relationship was found between the increase in erythrocyte magnesium and the disappearance or persistence of MVP and LVH. Therefore, the improvement of the patients' clinical status was not always followed by a significant change in erythrocyte magnesium values and in echocardiographic findings, even after long-term therapy.