Subclinical hypothyroidism effects on cardiac function.

Area of Science:

• Cardiology
• Endocrinology
• Thyroid Research

Background:

• Subclinical hypothyroidism (SH) is a condition characterized by elevated thyroid-stimulating hormone (TSH) levels with normal free thyroxine (FT4).
• The impact of SH on cardiac function, particularly diastolic function, remains incompletely understood.
• Early detection of cardiac changes in SH is crucial for timely intervention.

Purpose of the Study:

• To investigate and compare heart function, specifically diastolic and systolic parameters, in women with newly detected subclinical hypothyroidism versus healthy euthyroid women.
• To identify potential cardiac abnormalities associated with subclinical hypothyroidism using advanced imaging techniques.

Main Methods:

• A prospective case-control study involving 35 women with SH and 35 matched healthy controls.
• Two-dimensional echocardiography and Tissue Doppler Imaging (TDI) were utilized to assess cardiac function.
• Thyroid function tests (TSH and FT4) were performed for all participants.

Main Results:

• Women with SH exhibited significantly impaired left ventricular (LV) diastolic function compared to controls (60% vs. 31.4%, p=0.016).
• LV diastolic dysfunction was notably more frequent in SH patients aged 40 years or older (94.1% vs. 53.3%, p=0.013).
• Right ventricle (RV) systolic function showed a trend towards minor impairment in the SH group, evidenced by lower T(v) excursion.

Conclusions:

• Subclinical hypothyroidism is associated with an increased risk of left ventricular diastolic dysfunction.
• Age is a significant factor, with older women with SH being particularly susceptible to diastolic dysfunction.
• These findings suggest that SH may have subclinical detrimental effects on cardiac performance, warranting further investigation and potential clinical consideration.