Myocardial ultrasonic tissue characterization in patients with thyroid dysfunction

Abstract

BackgroundStructural myocardial abnormalities have been extensively documented in hypothyroidism. Experimental studies in animal models have also shown involvement of thyroid hormones in gene expression of myocardial collagen. This study was planned to investigate the ability of ultrasonic tissue characterization, as evaluated by integrated backscatter (IBS), to early identify myocardial involvement in thyroid dysfunction.Patients and MethodsWe studied 15 patients with hyperthyroidism (HYPER), 8 patients with hypothyroidism (HYPO), 14 patients with subclinical hypothyroidism (SCH) and 19 normal (N) subjects, who had normal LV systolic function. After treatment, 10 HYPER, 6 HYPO, and 8 SCH patients were reevaluated. IBS images were obtained and analyzed in parasternal short axis (papillary muscle level) view, at left ventricular (LV) posterior wall. The following IBS variables were analyzed: 1) the corrected coefficient (CC) of IBS, obtained by dividing IBS intensity by IBS intensity measured in a rubber phantom, using the same equipment adjustments, at the same depth; 2) cardiac cyclic variation (CV) of IBS - peak-to-peak difference between maximal and minimal values of IBS during cardiac cycle; 3) cardiac cyclic variation index (CVI) of IBS - percentual relationship between the cyclic variation (CV) and the mean value of IBS intensity.ResultsCC of IBS was significantly larger (p < 0.05) in HYPER (1.57 ± 0.6) and HYPO (1.53 ± 0.3) as compared to SCH (1.32 ± 0.3) or N (1.15 ± 0.27). The CV (dB) (HYPO: 7.5 ± 2.4; SCH: 8.2 ± 3.1; HYPER: 8.2 ± 2.0) and the CVI (HYPO: 35.6 ± 19.7%; SCH: 34.7 ± 17.5%; HYPER: 37.8 ± 11.6%) were not significantly different in patients with thyroid dysfunction as compared to N (7.0 ± 2.0 and 44.5 ± 15.1%).ConclusionsCC of IBS was able to differentiate cardiac involvement in patients with overt HYPO and HYPER who had normal LV systolic function. These early myocardial structural abnormalities were partially reversed by drug therapy in HYPER group. On the other hand, although mean IBS intensity tended to be slightly larger in patients with SCH as compared to N, this difference was not statistical significant.

Detection of radiotherapy-induced myocardial changes by ultrasound tissue characterisation in patients with breast cancer

“…The results of previous UCT studies in patients with prior myocardial infarction, cardiomyopathy, and doxorubicin-induced myocardial alterations indicate that there is a strong association between histological changes (e.g., scarring, collagen content) and increased myocardial backscattering [9][10][11]13]. Increased echodensity has also been found in patients with diabetes, thyroid dysfunction, iron overload and acute cardiac allograft rejection, despite no abnormalities in conventional echocardiographic parameters [14][15][16][17]. Moreover, RT has been shown to increase collagen content in myocardial biopsies several years after the treatment course has finished [7].…”

Thyroxine and cardiac electrophysiology—a forgotten physiological duo?

“…Thirdly, hypothyroidism can affect cardiac structure [ 11 - 13 ]. These structural effects manifests clinically in hypothyroidism as an increase in myocardial echoreflectivity [ 13 , 14 ], perhaps an explanation for the observed electrocardiographic abnormalities observed in hypothyroidism?…”

Υπερηχοκαρδιογραφική Μελέτη Της Διαστολικής Λειτουργίας Της Αριστερής Και Δεξιάς Κοιλίας Σε Ασθενείς Με Υπερθυρεοειδισμό

“…179,284 ,224,227 Ζ κνξθή απηή ηεο ζπζηνιηθήο δπζιεηηνπξγίαο ζπλήζσο αληηζηξέθεηαη κε ηελ απνθαηάζηαζε ηεο ζπξενεηδηθήο ιεηηνπξγίαο. 103 Ο ιφγνο γηα ηνλ νπνίν νξηζκέλνη αζζελείο αλαπηχζζνπλ «ππεξζπξενεηδηθή κπνθαξδηνπάζεηα» θαη πξνρσξεκέλε θαξδηαθή αλεπάξθεηα παξακέλεη άγλσζηνο 100 Δμήγεζε ζα κπνξνχζε λα είλαη ε θαηαζηξεπηηθή δξάζε ηεο εκκέλνπζαο ηαρπθαξδίαο. Σν παξαπάλσ εληζρχεηαη απφ ην γεγνλφο φηη δελ παξαηεξείηαη κπνθαξδηαθή θαηαζηξνθή ζην νπηηθφ θαη ζην ειεθηξνληθφ κηθξνζθφπην ζε αζζελείο κε εηθφλα δηαηαηηθήο κπνθαξδηνπάζεηαο απφ ππεξζπξενεηδηζκφ.…”