Left ventricular wall thickness discrepancies at end-diastole and mid-diastole: Reference values for cardiac CT

To investigate differences in left ventricular wall thickness (LVWT) measurements between end-diastole and mid-diastole using cardiac computed tomography (CCT) and establish LVWT reference values stratified by phase, sex, and region.

Subjects who underwent CCT without a history of cardiovascular disease or risk factors were retrospectively included between 2021 and 2024. LVWT was manually measured in each segment according to the American Heart Association's 17-segment model at end-diastole and mid-diastole. Regional LVWT was calculated as the average value of relevant segments.

The study included 187 subjects with a mean age of 51 ± 11 years, including 77 (41 %) men. Global LVWT was lower at end-diastole than at mid-diastole (5.7 ± 0.8 vs. 6.5 ± 0.9 mm, P < 0.001). Each segmental LVWT correlated significantly between end-diastole and mid-diastole (Pearson's correlation coefficient: 0.79-0.87). Segment 2 was thickest (8.1 ± 1.5 mm at end-diastole and 9.1 ± 1.7 mm at mid-diastole). LVWT was greater in men than in women (all P < 0.001). The upper limits of LVWT were 9.9 mm for women and 11.7 mm for men at end-diastole, and 11.8 mm for women and 13.1 mm for men at mid-diastole. LVWT progressively thinned from the base to the apex. Apical LVWT measured on short-axis and long-axis showed a small but statistically significant difference, particularly in Segment 16.

This study provides CCT reference values for LVWT at end-diastole and mid-diastole. Mid-diastolic LVWT was slightly greater than end-diastolic LVWT, with a statistically significant difference. Normal LVWT was greater in men than in women, with regional variations observed in both phases.