TH Treatment in Patients with Cardiac Disorders: General Aspects and Rationale

Thyroid hormones (TH) are the principal modulators of cardiovascular homeostasis in both physiological and pathological conditions, mainly regulating heart rate, cardiac contractility and vascular resistance, by genomic and non-genomic activities. In the present chapter, the most important events characterizing the TH regulation of the cardiac muscle at molecular and cellular levels will be described. In particular, the TH reduction observed in some pathological conditions and the switch from beneficial to progressively harmful effects will be discussed. Based on these observations, the possible cardio-protective role of TH replacement therapy in pathological context, involving TH deprivation and its potential clinical relevance will be evaluated.