Left Ventricular Diastolic and Systolic Functions in Patients with Hypothyroidism

Abstract

Background and objectives: Long standing hypothyroidism may impair myocardial relaxation, but its effect on systolic myocardial function is still controversial. The aim of this study was to investigate left ventricular (LV) systolic and diastolic function in patients with hypothyroidism. Materials and Methods: This study included 81 (age 42 ± 13 years, 92% female) patients with hypothyroidism, and 22 age and gender matched controls. All subjects underwent a detailed clinical examination followed by a complete biochemical blood analysis including thyroid function assessment and anthropometric parameters measurements. LV function was assessed by 2-dimensional, M-mode and Tissue-Doppler Doppler echocardiographic examination performed in the same day. Results: Patients had lower waist/hip ratio (p< 0.001), higher urea level (p = 0.002), and lower white blood cells (p = 0.011), compared with controls. All other clinical, biochemical, and anthropometric data did not differ between the two groups. Patients had impaired LV diastolic function (lower E wave [p< 0.001], higher A wave [p = 0.028], lower E/A ratio [p< 0.001], longer E wave deceleration time [p = 0.01], and higher E/e’ ratio [p< 0.001]), compared with controls. Although LV global systolic function did not differ between groups, LV longitudinal systolic function was compromised in patients (lateral mitral annular plane systolic excursion—MAPSE [p = 0.005], as were lateral and septal s’ [p< 0.001 for both]). Conclusions: In patients with hypothyroidism, in addition to compromised LV diastolic function, LV longitudinal systolic function is also impaired compared to healthy subjects of the same age and gender. These findings suggest significant subendocardial function impairment, reflecting potentially micro-circulation disease that requires optimum management.

Thyroid Hormones—An Underestimated Player in Dilated Cardiomyopathy?

“…Impaired LV relaxation prolongs isovolumic relaxation time and early mitral flow deceleration time with concomitant reduction of the ratio of the peak early and atrial mitral inflow velocity (E/A), all of which are consistent with mild LV diastolic dysfunction [14,15]. Discrete systolic dysfunction, if present, is reflected by prolonged isovolumic contraction [15] and lower LV performance along the longitudinal axis detected by novel echocardiographic techniques [14][15][16], while ejection fraction is generally within the normal range [14][15][16]. Accordingly, although cardiac output is reduced mainly due to bradycardia with a rather minor contribution of direct myocardial effects, hypothyroidism is rarely the primary cause of DCM [13].…”

“…As regards direct cardiac effects, beyond bradycardia and pericardial effusion, longterm hypothyroidism may lead to slowed active diastolic relaxation of cardiomyocytes and subtle systolic dysfunction owing to the influence of T3 on myosin isoforms and calciumbinding proteins [13]. Impaired LV relaxation prolongs isovolumic relaxation time and early mitral flow deceleration time with concomitant reduction of the ratio of the peak early and atrial mitral inflow velocity (E/A), all of which are consistent with mild LV diastolic dysfunction [14,15]. Discrete systolic dysfunction, if present, is reflected by prolonged isovolumic contraction [15] and lower LV performance along the longitudinal axis detected by novel echocardiographic techniques [14][15][16], while ejection fraction is generally within the normal range [14][15][16].…”

Thyroid replacement therapy effects on cardiac function in patients with hypothyroidism

“…Thyroid hormone deficiency leads to changes in cardiovascular hemodynamics, phenotype and contractility, and accelerated atherosclerosis. Overt hypothyroidism exerts effects on systolic and diastolic cardiac function and cardiac anatomy [1,2].…”