[Myxedema coma with hypervasopressinism. 2 cases]. / Coma myxoedémateux avec hypervasopressinisme. Deux observations.

Hyponatremia is usual during myxedema coma. Hereafter we report two cases with increased plasma arginine vasopressin (AVP). Patients were admitted because of hypothyroid coma. In each case, there was an hyponatremia with normal urine sodium and low serum osmolality. Renal function was normal. On hormonal results, primary hypothyroidism was evident. Plasma AVP was increased. The plasma cortisol of one patient was high. Immediate therapy associated: water restriction, hypertonic saline infusion, furosemide, oral thyroid hormones with low doses. On the fourth day, conscience improved obviously. Natremia and plasma AVP went back to normal state before returning to euthyroid state. Patients went on improving along with normalizing thyroid status. Hyponatremia can be a serious sign of hypothyroidism. In case of myxedema coma with hyponatremia, clinical improvement seems to be related to fast correction of water and electrolyte disturbances and we prefer to give low doses of thyroid hormones at first. The hyponatremia and increased plasma AVP mechanisms are complex. However, in each of these cases, plasma AVP come back to normal before returning to euthyroid state. In one case, high plasma cortisol level rules out adrenal insufficiency as causal mechanism of electrolyte disorders.

[Hyperthyroidism and mitral valve prolapse: comparative two-dimensional echocardiography study of a hyperthyroid and a control population totalling 104 patients]. / Hyperthyroïdie et prolapsus valvulaire mitral: Etude comparative par échocardiographie bidimensionnelle d'une population hyperthyroïdienne et d'une population témoin réunissant 104 patients.

Recent studies seem to demonstrate a higher incidence of mitral valve prolapse in hyperthyroid patients. A complete cardiological check-up including 2D echocardiography was performed in 52 hyperthyroid patients and 52 control subjects. In the hyperthyroid population, mitral valve prolapse was diagnosed 3 times, 5,8 p. 100 of cases. These 3 subjects were female; hyperthyroidism was nodular in 2 cases: Grave's disease was only present in 1 case. Hyperthyroidism was very active at the time of the echocardiographic study in those 3 patients. In the control group, mitral valve prolapse was observed in 4 cases (7.7 p. 100). These 4 patients were all female. The results of this study do not show a higher incidence of mitral valve prolapse in the hyperthyroid population than in the control group. Grave's disease was not more prevalent in hyperthyroid patients with mitral valve prolapse. On the other hand, there were significantly more female patients with MVP in both the hyperthyroid and control populations.