Subclinical hypothyroidism and left ventricular mechanics: a three-dimensional speckle tracking study

Area of Science:

• Cardiology
• Medical Imaging
• Endocrinology

Background:

• Subclinical hypothyroidism (SHT) is linked to left ventricular (LV) remodeling.
• LV mechanics in SHT patients have not been fully evaluated using 2D and 3D speckle tracking imaging.

Purpose of the Study:

• To investigate LV mechanics in SHT patients using 2D and 3D speckle tracking.
• To assess the impact of levothyroxine therapy on LV remodeling in SHT.

Main Methods:

• Prospective study at a university hospital.
• Included 54 untreated women with SHT and 40 healthy controls.
• Assessed 2D/3D LV strain, strain rates, volumes, cardiac output, ejection fraction, and thyroid hormones.

Main Results:

• SHT patients showed decreased 2D LV longitudinal/circumferential strain and strain rates before therapy.
• 3D LV cardiac output and ejection fraction were reduced in untreated SHT patients compared to controls and post-therapy.
• 3D LV longitudinal and radial strains were lower in untreated SHT patients, while circumferential and area strains showed a gradient from untreated SHT to controls.

Conclusions:

• SHT significantly impacts LV deformation, detectable by 2D and 3D speckle tracking.
• Levothyroxine treatment leads to significant, yet incomplete, improvement in LV mechanics after one year.