The left ventricular diastolic indices of the hyperthyroid (HTH) patients without cardiac disease (n=31) were compared with those of the normal controls (NC) (n=49) using echocardiography. The HTH group had a significantly shorter IIa-mitral valve opening time (IIa-MVO), and a significantly larger maximum descending rate of the left ventricular posterior wall (maxPWDR), peak E and peak A than the NC group. IIa-MVO, maxPWDR, peak E and E/A showed significant simple correlation with T
3 in the HTH group. To elucidate spurious correlation among these indices and T
3, partial correlation analysis among these indices and its influencing factors were calculated. IIa-MVO, maxPWDR and peak E showed significant partial correlation coefficients with T
3, but peak E had a lesser partial correlation with T
3 than with age and left ventricular end-diastolic volume. Fourteen of the hyperthyroid patients were reexamined after antithyroid treatment. Their diastolic indices were found to be normalized compared with pre-treatment values and showed no significant difference with those of NC group. Augmented myocardial relaxation in patients with hyperthyroidism correlated with the thyroid hormone level, and IIa-MVO and maxPWDR were more effective indices of left ventricular myocardial relaxation than peak E and E/A in hyperthyroidism.
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