Can speckle tracking echocardiography unmask cardiac involvement in obesity hypoventilation syndrome?

Obesity hypoventilation syndrome (OHS) is characterized by morbid obesity; most patients have class 3 obesity with a body mass index (BMI) > 35 kg/m², which is linked to breathing disorders during sleep and hypoventilation during the day, manifested as hypercapnic symptoms. Speckle tracking echocardiography (STE) provides segmental or global measurement of myocardial deformation, or "strain," in all heart chambers. It has the benefit of circumventing many of the conventional echocardiographic limitations. Our study aimed to develop an echocardiographic screening method for OHS and to assess its severity by using two-dimensional (2D) speckle tracking echocardiography (STE) for the early identification of subclinical LV impairment.

An observational cross-sectional study was conducted between July 2023 and August 2024 at the Cardiology and Chest Departments of Zagazig University Hospitals, in collaboration with the Cardiology Department at Al-Ahrar Teaching Hospital. Demographic and clinical characteristics, BMI, neck circumference, sleep assessment scores, polysomnography, and speckle tracking echocardiography were done.

Fifty-eight patients were classified according to STE findings into two groups: [Group I] 39 cases (67.2%) with impaired global longitudinal strain (GLS) and [Group II] 19 cases (32.8%) with normal GLS. GLS was meaningfully more impaired in severe illness compared to mild illness. In Group I, GLS showed a negative correlation with BMI.

Subclinical LV systolic impairment was present in 67.2% of OHS cases. LVGLS was more impaired in the severe stage (severe AHI). A higher AHI was associated with impaired LVGLS.