[Low T3 syndrome and left ventricular diastolic function].
BACKGROUND
Recent data suggest that low triiodothyronine (T3) syndrome may contribute to the pathophysiology of cardiac diseases. Because the development of diastolic dysfunction occurs early in a failing heart, we evaluated whether patients with low T3 syndrome show abnormalities in diastolic function, also in absence of overt cardiovascular disease.


METHODS
Thirty-four patients with low T3 syndrome and 34 controls with normal levels of free T3 (FT3) underwent a complete Doppler echocardiographic examination. Criteria of exclusion from the study were the presence of cardiovascular disease or traditional cardiovascular risk factors, a primitive thyroid disease, cachexia, and the use of drugs affecting the thyroid function.


RESULTS
Patients with low T3 syndrome, if compared with controls, show evidence of left ventricular diastolic dysfunction, documented by prolongation of the isovolumic relaxation time (120 vs 75 ms, p < 0.0001) and a reduction in the early diastolic mitral flow velocity/late diastolic mitral flow velocity ratio (0.66 vs 2.05, p < 0.0001), mainly due to the increased A-wave (0.96 vs 0.40 m/s, p < 0.0001). These alterations increase proportionally with FT3 reduction.


CONCLUSIONS
Patients with low T3 syndrome show evidence of impaired left ventricular relaxation. Doppler echocardiography may be a useful non-invasive technique for the assessment of diastolic performance in these patients.
Cassetti
Giuseppina
G
Medicina Interna IV, Azienda Ospedaliero-Universitaria Pisana, Pisa.
Pinelli
Massimiliano
M
Bindi
Massimo
M
Bianchi
Massimiliano
M
Castiglioni
Maido
M
D000368:Aged; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003971:Diastole; D015150:Echocardiography, Doppler; D005067:Euthyroid Sick Syndromes / Q000097:blood / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D005260:Female; D006331:Heart Diseases / Q000097:blood / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology; D016277:Ventricular Function, Left
D015415:Biomarkers; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine