Left Atrial Phasic Function and Mechanics in Women with Subclinical Hypothyroidism: The Effects of Levothyroxine Therapy

Abstract

Subclinical hypothyroidism significantly affects LA mechanics. Reservoir, conduit, and booster pump LA functions are all impacted by SHT. A 1-year levothyroxine therapy significantly improves, but does not completely restore LA phasic function and mechanics in the SHT patients.

Impact of Hypothyroidism on Echocardiographic Characteristics of Patients With Heart Valve Disease: A Single-Center Propensity Score-Based Study

“…The patients with hypothyroidism were found to display higher QT dispersion, lower heart rate variability (HRV), and aberrant diastolic velocities (6)(7)(8); levothyroxine treatment for hypothyroidism may bring cardiac benefits (6,9). Additionally, the adverse effect of hypothyroidism on cardiac structure has been demonstrated by some researchers, such as larger interventricular septum (IVS) thickness, left ventricular posterior wall (LVPW) thickness, and decreased left ventricular ejection fraction (LVEF), and they also confirmed the significant improvement after levothyroxine treatment (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). A retrospective cohort study found that in patients with dilated cardiomyopathy (DCM), patients with subclinical hypothyroidism had larger left ventricular (LV) and left atrial (LA) diameter and higher all-cause mortality (21).…”

“…Meanwhile, studies performed by Tadic et al (15,(17)(18)(19) in Serbia examined echocardiographic parameters in dozens of women with SCHypoT and healthy control women, and all the results showed no difference in LAD. Moreover, levothyroxine treatment of 1 year for the SCHypoT group failed to recover the LAD significantly (15,(17)(18)(19). More recently, Li et al compared LAD in Chinese DCM patients with or without SCHypoT and found significantly larger LAD in SCHypoT group.…”

Evaluation of left atrial volume and functions by real time three‐dimensional echocardiography in patients with subclinical hypothyroidism before and after levothyroxine therapy

“…These findings are similar to those of the other studies evaluating the LA mechanical functions in patients with SCH and especially to that of the Tadic et al study. [9][10][11][12] Larger-scale studies have demonstrated that the increase left ventricular stiffness and impaired left ventricular relaxation in patients with SCH. 25,26 These changes might have caused the reduction in LA passive emptying volume and passive emptying fraction TA B L E 5 Three-dimensional echocardiographic left atrial volume and function variables of control group and patients with SCH before and after treatment F I G U R E 1 Negative correlation between the change of left atrial active emptying fraction and change of thyroid stimulating hormone after (median 86 days) thyroid hormone replacement therapy.…”

“…4,5 Cardiac injury in subclinical thyroid dysfunction, especially in hypothyroidism, have received attention in the last decad. [9][10][11][12] Today, different studies have shown that RT3DE provides accurate measurement of LA volume and function and it is a viable and reproducible method for clinical benefit. 7 and two-dimensional speckle tracking in patients with SCH but real time three-dimensional echocardiography (RT3DE) has never been used in the studies at all.…”

“…A limited number of studies have investigated left atrium (LA) volume and functions with conventional echocardiography and two-dimensional speckle tracking in patients with SCH but real time three-dimensional echocardiography (RT3DE) has never been used in the studies at all. [9][10][11][12] Today, different studies have shown that RT3DE provides accurate measurement of LA volume and function and it is a viable and reproducible method for clinical benefit. Subclinical cardiac involvement with impaired LA function had been revealed by using RT3DE.…”