KUMJ | VOL. 17 | NO. 4 | ISSUE 68 | OCT.-DEC. 2019

Prolonged QT dispersion in Subclinical Hypothyroid Females: A Study in University Teaching Hospital in Central Nepal
Kandel S, Rana BSJB, Prasad PN, Mahotra NB, Shrestha TM

Abstract:
Background QT dispersion is a simple index derived from 12 lead ECG; its prolongation has been shown to be associated with increased arrhythmia risk. Increased cardiovascular risks, particularly occurrence of the malignant arrhythmias are a common finding in patients with subclinical hypothyroidism. This increased arrhythmia risk is found to be higher mainly in patients with TSH level more than 10 milli international unit per liter. Objective To assess QT dispersion among subclinical hypothyroid and euthyroid Nepalese females aged 20-59 years attending general practice out patient department of centrally located University Teaching Hospital from November 2016 to April 2017. Method Forty-three newly detected subclinical hypothyroid females and forty-one euthyroid females were enrolled. Resting electrocardiogram (ECG) was performed. QT dispersion was analyzed from ECG and corrected for heart rate using Framingham correction formula. Independent sample t-test was applied to compare mean QT dispersion between two groups. Pearson correlation test was used to examine the association between QT dispersion and TSH level. Result Mean QT dispersion for sub-clinical hypothyroid group was 75.35 ± 43.82 whereas mean QT dispersion for euthyroid group was 59.51 ± 22.13, with p value 0.041. A weak association between QT dispersion and TSH level was seen with correlation factor of 0.23. Conclusion The result showed prolongation of QT dispersion in sub-clinical hypothyroid group and weak positive correlation between TSH level and QT dispersion suggesting arrhythmia risk in subclinical hypothyroid females.
Keyword : Arrhythmia risk, QT dispersion, Sub-clinical hypothyroidism