Prolapse of the mitral valve in hyperthyroid patients in Saudi Arabia.

Eighty-two patients (60 females and 22 males) who were under treatment for hyperthyroidism at the King Saud University affiliated hospitals in Riyadh, Saudi Arabia, were evaluated by M-mode and cross-sectional echocardiography for the presence of mitral valve prolapse. Sixty-seven patients (51 females and 16 males) had diffuse toxic goitre while 15 of them (9 females and 6 males) had nodular toxic goitre. The overall frequency of prolapse was 37.8% (31 of 82) and the frequency was similar for both sexes, being 38.3% in females and 36.3% in males. Prolapse was associated with both diffuse toxic goitre (overall frequency 35.8%) and nodular toxic goitre (overall frequency 46.6%); and the highest frequency was in females with nodular toxic goitre (55.5%). Out of the total of 31 patients with prolapse, early systolic and holosystolic prolapse were each present in 12 patients, while mid-to-late systolic prolapse was found in 7 patients. Cross-sectional echocardiography demonstrated prolapse in 16 cases, the M-mode was positive in 5 cases while the two methods confirmed it in 10 patients. The prevalence of prolapse of the mitral valve in otherwise healthy Saudi subjects has previously been found to be 12-15%. This study has confirmed a high frequency of prolapse in hyperthyroid patients and has demonstrated that sex, ethnic or racial origin and type of hyperthyroidism are not determinants of this association.