Moreover, vascular effects of thyroidhormones may contribute to enhance diastolic function as well.3 Experimental data also suggest that it may decrease myocardial stiffness as arat model of propylthiouracil-induced hypothyroidism showed increased LV stiffnessdue to increased collagen deposition, despite overexpression of the larger and morecompliant (N2BA) isoform of titin.54 Nevertheless, the effects on titin are not settled. This evidence concerns the gene TTN and hypothyroidism.