Assessment of Left Ventricular Diastolic Dysfunction in Sub-clinical Hypothyroidism

Abstract

Background:Adverse cardiovascular effect of hypothyroidism has been identified in many studies. Early identification of patients with sub-clinical hypothyroidism may lead to early treatment and thereby favourable effect on cardiovascular morbidity and mortality.Objectives:To find out the association of sub clinical hypothyroidism and left ventricular dysfunction and also to find out relationship between systolic and diastolic dysfunction in these patients.Material and Methods:A total 30 cases of sub clinical hypothyroidism along with 15 age sex matched healthy control subjects were included in study. Serum TSH, T4, T3 hormone level was measured and those who were found to have sub-clinical hypothyroidism underwent for 2DEcho.Results:Significant reduction in peak early filling velocity (PE) (p<0.001) and early filling time velocity integral (Ei) (p<0.001). Ratio of early and late peak velocities (PE/PA) (p<0.001), ratio of time velocity integral of early and atrial filling (Ei/Ai) (p<0.001) and ratio of the early peak to average velocity (PE/M) (p<0.001) were also reduced. Mean EF was 54.9± 5.55 as compared to 55.7 ± 3.46 of control subjects with a T.value of 0.48 ,however there was significant diastolic dysfunction in case of hypothyroid patients (mean Ei/Ai = 1.35 ± 0.53) as compared to control group subjects (mean Ei/AI = 2.11 ± 0.26) with a T value of 5.22.Conclusion:Sub-clinical hypothyroidism showed significant diastolic dysfunction in the absence of significant impairment of systolic function.

Echocardiographic evaluation of cardiac function in hypothyroidism

“…The ejection fraction does not significantly vary between two groups. Our findings were correlated with various studies [6,7,13] .…”

“…Among 32 hypothyroid patients 6.25% were males and 93.75% were females while among 15 controls 13.33% were males and 86.66% were females, suggesting that female preponderance in our study. Most of the other studies [6][7][8] conducted had also female preponderance suggesting disease being more common in female population. Out of 32 hypothyroid patients 18 (56.2%) were subclinical while 14 (43.75%) patients presented with us as an overt hypothyroid.…”

“…The mean age of hypothyroid patients was 40.90±8.73 years while the mean age of controls was 40.06±9.68 years. The literature review [5][6][7] found various differences in mean age of patients; this might be due to racial variation. Among 32 hypothyroid patients 6.25% were males and 93.75% were females while among 15 controls 13.33% were males and 86.66% were females, suggesting that female preponderance in our study.…”

Right ventricular and right atrial function and deformation in patients with subclinical hypothyroidism: a two- and three-dimensional echocardiographic study

“…The influence of subclinical thyroid dysfunction on the heart and the cardiovascular system is significantly less studied, and pathophysiological mechanisms of this relationship are still unclear (2). Studies showed that subclinical hypothyroidism (SHT) is associated with left ventricular remodeling, especially hypertrophy and diastolic dysfunction (3,4,5,6,7,8). However, the influence of SHT on the right ventricle (RV), as well as the effect of levothyroxine (L-T 4 ) therapy on RV remodeling, has been investigated in several studies which used only pulsed and tissue Doppler for the estimation of RV function (9,10,11,12,13,14).…”

Clinical and pathogenetic role of immunoinflammatory activation and endothelial dysfunction in patients with coronary heart disease associated with hypothyroidism based on the results of cognitive modeling

“…It is proved that the structural changes in the myocardium due to reduction of the thyroid gland function lead to a violation of intracardiac hemodynamics: reduced myocardial contractile function, its electrical instability, disruption of atrioventricular conduction, lengthening of diastole, reduced left ventricular ejection fraction [4,5]. Hypothyroidism is accompanied with the violation of functional state of the autonomic nervous system; it leads to the imbalance of sympathetic and parasympathetic influences on the heart and increases the variability of the QT interval, which significantly affects the course of both CHD and hypothyroidism [6].…”