Figure 2. Transthoracic parasternal short axis view obtained in
the prone position by the TEE probe at angle 77°
A: At the level of mitral valve
leafletsB: At the level of papillary muscles
obtained by clockwise rotationC: At the level of great vessels
obtained by counterclockwise rotation
Statistical analysis
Continuous variables were presented as means ± standard deviation (SD)
or medians with interquartile range (IQR) and compared with Student’s
t-tests or the Mann-Whitney U test. Categorical variables were reported
as numbers and percentages and compared with the Chi- square or Fisher
exact test (for cells < 5).
A Pearson correlation coefficient was computed to assess the
relationship between each of the LV dimensions, EF, aortic root and LA
dimensions indexed to body surface area in both the prone and the supine
positions. An independent-samples t-test was conducted to compare
differences in the mean diameter for each parameter between both
positions. Bland-Altman plots were performed to show accuracy and
agreement between each of LV- end diastolic diameter (LVEDD), LV- end
systolic diameter (LVESD), septal wall thickness (SWT), posterior wall
thickness (PWT), and aortic root dimensions (AoR) in the prone position
vs the standard supine position.
Two-tailed p values < 0.05 were considered significant.
Statistical analyses were performed by using the IBM Statistical Package
for Social Sciences (SPSS) for Windows version 25.0 (IBM SPSS Inc. USA).
Results
Overall, 30 non-COVID-19 patients were enrolled in our study. Mean (SD)
age of patients was 35 (10.9) years and 11 patients (36.7%) were
females. One patient had hypertension, 1 patient had non-insulin
dependent diabetes mellitus (DM) and 8 patients were smokers. Mean (SD)
BMI was 26.4 (5.9) kg/m2 and mean (SD) BSA was 1.8 (0.2) m2.
There were no significant differences between LVEDD, LVESD, SWT, PWT and
AoR dimensions in the prone vs the supine positions. While there was a
significant difference between the mean ejection fraction (60.3% vs
63.1%, P = 0.014) and mean LA dimensions (1.8 [0.2] vs 1.9 (0.2)
cm/m2, P < 0.001) in the prone position as compared to the
supine position (table 1).
Table 1. Comparing differences between each of the LV
dimensions, ejection fraction, aortic root and LA dimensions in the
prone vs supine
positions.