Arterial-ventricular coupling and tolerance to physical exertion in patients with primary hypothyroidism

Aim. To study the influence of medicamentous compensation of primary hypothyroidism on tolerance to physical exertion and arterial-ventricular coupling. Material and methods. Thirty-one women with primary hypothyroidism underwent stress-echocardiography before and after medicamentous achievement of euthyroid state. Subclinical hypothyroidism was diagnosed in 15 patients. Overt hypothyroidism was diagnosed in 16 patients. Results are presented with 95% confidence interval. Results. In patients with subclinical hypothyroidism reaching of euthyroid state was associated with an increase of physical capacity from 72.2 (55.9–88.5) to 95.5 (82.1–108.9) Wt (p  0.001), a decrease in arterial stiffness index from 4.80 (4.45–5.15) to 3.87 (3.56–4.18) mm Hg × ml-1 × m-2 (p  0.001), a decrease in left ventricular stiffness index from 6.67 (6.03–7.31) to 5.87 (5.30–6.44) mm Hg × ml-1× m-2 (p  0.005). In patients with overt hypothyroidism reaching of euthyroid state was associated with an increase of physical capacity from 75.4 (64.1–86.6) to 98.2 (88.6–107.7) Wt (p  0.001), a decrease in arterial stiffness index from 4.56 (4.18–4.94) to 4.00 (3.73–4.27) mm Hg × ml-1 × m-2 (p  0.001), a decrease in left ventricular stiffness index from 6.47 (5.86–7.08) to 6.13 (5.69–6.57) mm Hg × ml-1 × m-2 (p  0.05). In patients with subclinical hypothyroidism cardiovascular arterial-ventricular coupling index decreased from 0.72 (0.69–0.75) to 0.66 (0.62–0.71) units. In patients with overt hypothyroidism cardiovascular arterial-ventricular coupling index decreased from 0.71 (0.67–0.74) to 0.66 (0.63–0.69) units. In the whole group gain of left ventricular stiffness index after physical exertion increased from 4.13 (3.67–4.59) to 6.05 (5.60–6.50) mm Hg × ml-1 × m-2 (p  0.01), cardiovascular arterial-ventricular coupling index increased from 0.07 (0.03–0.10) to 0.14 (0.11–0.17) units (p 0.01)