Abnormal cardiac contractility in long-term exogenous subclinical hyperthyroid patients as demonstrated by two-dimensional echocardiography speckle tracking imaging.

Abstract

BACKGROUND:

Subclinical hyperthyroidism is associated with cardiovascular morbidity. Recent advances in echocardiography imaging have allowed sophisticated evaluation of myocardial tissue properties.

OBJECTIVE:

To investigate the myocardial effects of long-term exogenous subclinical hyperthyroidism using two-dimensional speckle tracking echocardiography imaging (2D-STE).

DESIGN:

Prospective, single-blinded, placebo-controlled randomized trial of 6 months duration with two parallel groups.

PATIENTS AND METHODS:

Totally 25 patients with a history of differentiated thyroid carcinoma on long-term TSH-suppressive levothyroxine (l-T(4)) substitution were randomized to persistent TSH-suppressive l-T(4) substitution (low-TSH group) or restoration of euthyroidism. Additionally 40 euthyroid controls were studied. RESULTS (PROPOSAL): At baseline, the group of patients showed normal left ventricular (LV) systolic function but impaired diastolic function as assessed with conventional echocardiographic parameters. Importantly, 2D-STE analysis demonstrated the presence of subclinical LV systolic and diastolic dysfunction with impaired circumferential and longitudinal strain and strain rate at the isovolumic relaxation time. After restoration of euthyroidism, a significant improvement in LV systolic and diastolic function as assessed with 2D-STE strain was observed.

CONCLUSION:

Prolonged subclinical hyperthyroidism leads to systolic and diastolic dysfunction, which is reversible after restoration of euthyroidism. 2D-STE is a more sensitive technique to evaluate subtle changes in LV performance of these patients.

• Authors: Randa M Abdulrahman, Victoria Delgado, Arnold C T Ng, See Hooi Ewe, Matteo Bertini, Eduard R Holman, Guido C Hovens, Alberto M Pereira, Johannes A Romijn, Jeroen J Bax, Johannes W Smit
• Journal: European journal of endocrinology (Eur J Endocrinol) Vol. 163 Issue 3 Pg. 435-41 (Sep 2010) ISSN: 1479-683X [Electronic] England
• PMID: 20587582 (Publication Type: Comparative Study, Journal Article, Randomized Controlled Trial)

Topics

• Adult
• Blood Pressure
• Cohort Studies
• Echocardiography (methods)
• Female
• Follow-Up Studies
• Humans
• Hyperthyroidism (complications, diagnostic imaging, physiopathology)
• Male
• Middle Aged
• Myocardial Contraction (physiology)
• Prospective Studies
• Single-Blind Method
• Time Factors
• Ventricular Dysfunction, Left (diagnostic imaging, etiology, physiopathology)