Isovolumetric Relaxation Time (IVRT): An Effective Tool in Management of Subclinical Hypothyroidism

Abstract

Hypothyroidism is a common condition in which thyroid gland doesn't produce sufficient thyroid hormone. Normal range of TSH is 0.4 to 4 mIU/L. Patients with TSH between 5 and 10 mIU/L, with normal T4 are diagnosed to have subclinical hypothyroidism. Decision to treat, particularly the subclinical hypothyroidism is tailored to individual patients. In our study, isovolumetric relaxation time (IVRT) was used to detect the diastolic function of cardia in hypothyroid patient, with the help of 2D echocardiogram. Normal duration of IVRT is 54 to 65μs and in hypothyroidism it is expected to increase. To assess, whether IVRT is an effective tool in the management of subclinical hypothyroidism. 50 patients attending otorhinolaryngology OPD with TSH level of 5 to 10 mIU/L were selected for the study. All these were sent for 2D echocardiogram, for the measurement of IVRT. These 50 patients were divided into 2 groups. Group A-patients with TSH level 5 to 10 mIU/L and normal IVRT. Group B-patients with TSH level 5 to 10 mIU/L and prolonged IVRT. Patients in Group A were not given thyroxine, and after 3months, they were reviewed with TSH level and IVRT duration. Patients in Group B were started with thyroxine, and after 3months, they were reviewed with TSH level and IVRT duration. The basal and 3months follow up values of TSH and IVRT was analysed on both the groups. The p value of group A was not significant, but p value group B was significant. IVRT as a measuring tool in sub clinical hypothyroidism will definitely bring a major change in the concepts of treatment.