Thyroid and Heart: A Fatal Pathophysiological Attraction in a Controversial Clinical Liaison

Abstract

The thyroid–heart relationship has a long and articulated history of its own, a history that encompasses physiological and pathophysiological knowledge. In recent years, molecular biology studies, in an experimental context, have highlighted the extraordinary dialogue that exists among the two systems in the field of cardioprotection, which is an extremely important area for the treatment of cardiac diseases in both acute and chronic phases. In addition, in the last few years, several studies have been carried out on the prognostic impact of alterations in thyroid function, including subclinical ones, in heart disease, in particular in heart failure and acute myocardial infarction, with evidence of a negative prognostic impact of these and, therefore, with the suggestion to treat these alterations in order to prevent cardiac events, such as death. This review provides a comprehensive summary of the heart–thyroid relationship.

Pulmonary Hypertension and Hypothyroidism—Still an Important Clinical Coincidence in Paediatric Population, an Endocrinologist’s Point of View

“…Hypothyroidism has a direct effect on the cardiovascular system, with decreased cardiac contractility, increased diastolic blood pressure, and systemic vascular resistance [ 1 , 10 , 13 , 26 , 27 , 28 ]. On a molecular level, it decreases nitric oxide synthase expression and influences adenosine production, leading to decreased vasodilation.…”

“…It has been postulated that hypothyroidism in a course of AITD and PH, especially IPAH, may present common pathogenic mechanisms (Figure 1) [1]. Hypothyroidism has a direct effect on the cardiovascular system, with decreased cardiac contractility, increased diastolic blood pressure, and systemic vascular resistance [1,10,13,[26][27][28]. On a molecular level, it decreases nitric oxide synthase expression and influences adenosine production, leading to decreased vasodilation.…”

“…Although antinuclear antibodies were present in all adults with BMPR2 mutations, autoantibodies characteristic of a specific connective tissue disease were absent [29]. The recent studies show higher frequency of Hypothyroidism has a direct effect on the cardiovascular system, with decreased cardiac contractility, increased diastolic blood pressure, and systemic vascular resistance [1,10,13,[26][27][28]. On a molecular level, it decreases nitric oxide synthase expression and influences adenosine production, leading to decreased vasodilation.…”

“…Other indirect actions depend on the adrenergic nervous system or renin–angiotensin–aldosterone system [ 1 , 12 ]. Both hypothyroidism and hyperthyroidism may lead to PH [ 1 , 13 ]. It is hypothesised that AITD and PH may have similar pathogenic backgrounds, from autoimmunity, to heart dysfunction, to angioproliferation profiles [ 1 , 10 ].…”

Thyroid Dysfunction in Advanced Heart Failure Patients and Its Correlation with Amiodarone Therapy: A Two-Year Study

“…This scrutiny has specifically extended to discerning the potential effects of these hormones on diverse outcomes in individuals facing HF [ 46 ]. Pingitore et al explored that T3 serum concentrations might independently predict both left ventricular (LV) dysfunction and the functional class assigned by the New York Heart Association [ 47 ]. According to Gerdes et al and Cappola et al, thyroid dysfunction is emerging as a modifiable risk factor for individuals who are at risk of developing heart failure.…”