The Effects of L-thyroxine Treatment on QT Dispersion in Primary Hypothyroidism
Journal of Korean Medical Science
; : 114-116, 2007.
Article
in English
| WPRIM (Western Pacific)
| ID: wpr-226395
Responsible library:
WPRO
ABSTRACT
Hypothyroidism has various cardiovascular manifestation and exhibits electrocardiographic change. The QT dispersion on surface ECG reflects regional variations in myocardial repolarization. The effect of L-thyroxine treatment on ECG parameters, such as QT dispersion, in patients with primary hypothyroidism were investigated. This study involved 18 patients (3 men, 15 women, ages 48+/-18 yr) with primary hypothyroidism. All patients were checked with a standard 12-lead ECG before and after L-thyroxine treatment. Various ECG parameters were then measured twice. The mean L-thyroxine treatment duration was 22+/-2.7 months. The mean thyroid-stimulating hormone levels of patients before and after therapy were 40.2+/-29.8 microU/mL, 3.6+/-4.6 microU/mL (p<0.001) and free-T4 levels were 0.44+/-0.38 ng/dL, 1.51+/-0.39 ng/dL (p<0.001). After L-thyroxine treatment, QT interval (395+/-42 vs. 380+/-24 msec, p<0.05), QTc interval (434+/-32 vs. 417+/-23 msec, p<0.05), QT dispersion (45+/-23 vs. 30+/-13 msec, p=0.008), QTc dispersion (49+/-23 vs. 32+/-14 msec, p=0.005) significantly decreased. There were no significant changes in the PR and RR intervals, as well as the QRS duration. Our findings suggest that the thyroid hormone affects ventricular inhomogenicity, and that L-thyroxine replacement therapy may reduce malignant ventricular arrhythmia and sudden cardiac death in primary hypothyroidism.
Full text:
Available
Health context:
SDG3 - Target 3.4 Reduce premature mortality due to noncommunicable diseases
Health problem:
Endocrine System Diseases
Database:
WPRIM (Western Pacific)
Main subject:
Thyroxine
/
Electrocardiography
/
Hypothyroidism
Limits:
Adult
/
Female
/
Humans
/
Male
Language:
English
Journal:
Journal of Korean Medical Science
Year:
2007
Document type:
Article