Changes in autonomic regulation and ventricular repolarization induced by subclinical hyperthyroidism

Biomedicine & Pharmacotherapy = Biomédecine & Pharmacothérapie
F GalettaA Antonelli

Abstract

The aim of the present study was to evaluate the effect of subclinical hyperthyroidism (SHT) on cardiovascular autonomic function and ventricular repolarization. Thirty subjects (25 females; mean age 49.6 ± 9.8 years) with SHT, as judged by reduced TSH serum levels and normal free T4 and T3 serum levels, and 30 age and sex-matched control subjects underwent standard 12-lead ECG, and 24h ambulatory ECG monitoring. The dispersion of the QT interval, an index of inhomogeneity of repolarization, and the heart rate variability (HRV), a measure of cardiac autonomic modulation, were studied. Patients with SHT showed higher QT dispersion (p<0.001) and lower HRV measures (0.01>p<0.001) than controls. In SHT patients, QT dispersion was inversely related to HRV (r=-0.47, p<0.01). The results of the present study demonstrated that SHT is associated with a sympathovagal imbalance, characterized by increased sympathetic activity in the presence of diminished vagal tone, and with an increased inhomogeneity of ventricular recovery times. The assessment of HRV and QT dispersion in patients with SHT may represent a useful tool in monitoring the cardiovascular risk of this condition.

References

Nov 10, 1994·The New England Journal of Medicine·C T SawinR B D'Agostino
May 1, 1993·Circulation·R PolikarP Nicod
Aug 26, 1999·Pacing and Clinical Electrophysiology : PACE·M NakagawaM Ito
Jun 30, 2000·Clinical Cardiology·B M FadelK D Burman
Feb 15, 2001·The New England Journal of Medicine·I Klein, K Ojamaa
Dec 3, 2002·Annals of Internal Medicine·Bernadette BiondiSerafino Fazio
Apr 8, 2003·The Journal of Clinical Endocrinology and Metabolism·José A SgarbiJoão H Romaldini
Sep 1, 2005·The Journal of Clinical Endocrinology and Metabolism·J W A SmitJ J Bax
Feb 16, 2006·Hormone and Metabolic Research = Hormon- Und Stoffwechselforschung = Hormones Et Métabolisme·M OweckiJ Sowiński
Mar 2, 2006·JAMA : the Journal of the American Medical Association·Anne R CappolaPaul W Ladenson
Aug 26, 2006·Biomedicine & Pharmacotherapy = Biomédecine & Pharmacothérapie·F GalettaG Santoro
Aug 29, 2006·Biomedicine & Pharmacotherapy = Biomédecine & Pharmacothérapie·F FranzoniG Santoro
Jan 2, 2008·European Journal of Endocrinology·Fabio GalettaAlessandro Antonelli

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Citations

Apr 12, 2019·The Journal of Clinical Hypertension·Peng CaiXukai Wang
Dec 8, 2017·The British Journal of Radiology·Hyun Gi KimSieun Lee
Apr 30, 2014·Hormones : International Journal of Endocrinology and Metabolism·Carlo CappelliMaurizio Castellano
Aug 30, 2018·Brazilian Journal of Medical and Biological Research = Revista Brasileira De Pesquisas Médicas E Biológicas·É J F Peixoto de MirandaI M Benseñor
Oct 5, 2021·International Journal of Clinical Practice·Altan Aydin, Kadriye Gayretli Yayla

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