Τόμος 27 (2009) – Τεύχος 1 – Άρθρο 33 – Επιθεώρηση Κλινικής Φαρμακολογίας και Φαρμακοκινητικής-Ελληνική Έκδοση – Volume 27 (2009) – Issue 1– Article 33 – Epitheorese Klinikes Farmakologias και Farmakokinetikes-Greek Edition

Μελέτη της Σχέσης μεταξύ των Επιπέδων Θυρεοειδικής Ορμόνης στο Αίμα και Δεικτών Καρδιακής Λειτουργικότητας σε Ασθενείς με Χρόνια Καρδιακή Ανεπάρκεια και σε Επίμυες με Έμφραγμα του Μυοκαρδίου

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Ελληνικά – Greek

Στατιστική Μελέτη

Statistical Study

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During development of heart failure, extensive remodeling of the myocardium occurs, accompanied by alterations in the expression of functional and structural myocardial proteins in the direction of the fetal phenotype. It can be hypothesized that these changes are due to changes in the thyroid hormone system, since cardiovascular system appears to be targeted by thyroid hormones through thyroid nuclear receptors that regulate the expression of myocardial proteins. The present work studies the relation between thyroid hormone blood levels in patients with heart failure and the function of the myocardium based on echocardiographical indexes. Additionally, an experimental model of heart failure in rats was used to test the hypothesis that the thyroid hormone administration in heart failure patients may assist them therapeutically, inducing cardiac remodeling. In the clinical study, 45 patients were included. Myocardial performance was assessed by echocardiography and total T3, T4 and TSH were measured in serum. Total T3 was strongly correlated with EF% (r=0.51, p=0.00037). A weaker but significant correlation was also found between T3 and LA (r=-0.35, p=0.028). In experimental study 27 male rats were included. Myocardial performance was assessed echocardiographicaly and ex vivo. Total T3, T4 were measured in serum and electrophoresis, after proper manipulations, of a small piece of left ventricular tissue from each sample was made to evaluate MHCα and MHCβ levels. Left ventricular internal diameters, LVIDs, of the AMI-THYR group were found to be significantly smaller than those of the AMI group. A significant augmentation of the left ventricular ejection fraction, LVEF%, of the AMI-THYR group relative to the AMI group was also observed (p<0.05). The systolic velocity of the posterior wall, SVPW, was found to be increased in the AMI-THYR group compaired to the two other groups (p<0.05). In the 13th week an important reduction in heart function was noticed as far as the AMI group was concerned. In contrast, normal contractility indexes were noted in the AMI-THYR group (p<0.05). Finally, thyroid hormone administration was found to alter the expression myosin isoforms. Τhere was a statistically significant increase in the MHCα isoform versus the MHCβ isoform (p<0.05).