Cited 15 times since 2010 (1.1 per year) source: EuropePMC European journal of endocrinology, Volume 163, Issue 3, 29 5 2010, Pages 435-441 Abnormal cardiac contractility in long-term exogenous subclinical hyperthyroid patients as demonstrated by two-dimensional echocardiography speckle tracking imaging. Abdulrahman RM, Delgado V, Ng AC, Ewe SH, Bertini M, Holman ER, Hovens GC, Pereira AM, Romijn JA, Bax JJ, Smit JW
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.
