Correlation of echocardiographic parameters in prone and supine positions in normal adults using a novel approach

Transthoracic echocardiography (TTE) in prone position is challenging. Innovative use of transesophageal echocardiography (TEE) probe to perform TTE for such patients has been described; but reproducibility and correlation of the TTE measurements by this technique with those obtained by the standard supine TTE study are still unknown.

We enrolled 30 non-COVID-19 individuals, with a mean (SD) age 35 (10.9) years and 11 females, to study the agreement between the transthoracic measurements of the left ventricular (LV), left atrial (LA), aortic dimensions, and ejection fraction (EF) obtained in prone position using an external TEE probe versus the standard supine position using the conventional TTE probe.

There were no significant differences between LV end-diastolic and end-systolic diameters, septal wall thickness, posterior wall thickness, and aortic root dimensions in the prone versus the supine positions, while the mean EF (60.3% vs 63.1%, P = .014) and mean LA dimensions (1.8 vs 1.9 cm/m² , P < .001) were significantly lower in the prone position. The mean time of scans was significantly longer in the prone as compared to the supine position (12.5 vs 4.5 minutes, P < .001). All supine studies had good quality while in the prone position four studies were of poor quality, and one was nondiagnostic.

Assessment of cardiac dimensions and systolic function in the prone position using transthoracic TEE probe was feasible. LV and aortic dimensions agreed well with the standard TTE in supine position; however, LA dimensions and EF were lower in the prone position.