CARDIOVASCULAR INVOLVEMENT IN HYPERTHYROIDISM

• Published in: Revista medicală Română Vol. 66; no. 3; pp. 250 - 26
• Main Authors: Delia Voiculescu, Ştefan S. Busnatu, Irina Dimitriu, Crina Julieta Sinescu
• Format: Journal Article
• Language: English
• Published: Amaltea Medical Publishing House 01.09.2019
• Subjects: hyperthyroidism; nt pro bnp; pah; rv basal diameter; tapse
• ISSN: 1220-5478; 2069-606X
• DOI: 10.37897/RMJ.2019.3.14

Introduction. Right ventricle was long time considered to be the „insignificant chamber“, while recent studies demonstrate that the right ventricle dilatation and sistolic dysfunction, is associated with increased cardiovascular mortality and morbidity. This finding might be explained by the effect of thyroid hormone on increasing the total blood volume, venous return and pulmonary capillary pressure, with the secondary consequence on increasing the right ventricle volume flow and intracavitary pressure. Because of the complexity of this chamber, the measurement of RV dimensions and systolic function is nowadays a challenge, best evaluated by cardiac magnetic resonance. But 2D echocardiography, we also used in our study, still remains the usual method, because is not expensive and accesible. Objective. The aim of this retrospective study, is to summarise the cardiovascular effects of hyperthyroidism, especially on the right ventricle. Hyperthyroid patients are represented by the low seric thyroid stimulating hormone (TSH) level group (<0.4 μUI/ml) and the most common ethiology of the disease is autoimmune and thyroid nodules. Methodology. We included in our study 82 patients with hyperthyroidism, half of them with low TSH level and half of them with normal TSH level after treatment. A diagnosis of hyperthyroidism was reached by measuring the decreased serum TSH level. Using echocardiography parameters and laboratory tests, we studied if there is any correlation between TSH and (NT terminal of the brain natriuretic peptide) NT pro BNP, RV dimension, tricuspid regurgitation severity, pulmonary arterial hypertension degree (PAH), atrial fibrillation incidence and longitudinal RV sistolic function (TAPSE). Results. As expected for this pathology, the majority of the hyperthyroid patient were women (78%). According to T test, RV basal diameter, tricuspid regurgitation severity and NT pro BNP were statistically significantly higher in hyperthyroid patients compared with patients with normal TSH level after treatment (P= 0.04, P=0.00 respectively P=0.001). There was no statistically significant positive correlation between TAPSE and the TSH levels, probably because only a minority of the patients (6 subjects) had thyreotoxicosis. Conclusions. Our study showed statistically significant negative correlation between RV dimension basal diameter, NT pro BNP, tricuspid regurgitation and TSH levels in patients with hyperthyroidism, which may be an important sign of clinical right cardiac involvement. It is interesting to speculate on the basis of the high prevalence of RV increased dimensions, that many of the clinical signs of right heart failure can be correlated to TSH level.