Transthoracic versus intra-operative transesophageal echocardiography in right heart assessment

Abstract

Background: Right heart geometry and function is routinely assessed at the time of valve surgery utilizing intra-operative 2-dimensional transesophageal echocardiography (TEE). However, the correlation between TEE-derived and established transthoracic (TTE) measurements of right heart size and function is unknown. We aimed to compare quantitative echocardiographic parameters of tricuspid annular (TA), tricuspid valve, and right ventricular (RV) size and function as assessed by TTE and intra-operative TEE. Methods: Fifty-four patients who had combined mitral and tricuspid valve surgery were included. Right heart measurements were performed in the TTE apical 4-chamber (A4C) and RV inflow views, and TEE mid-esophageal 4-chamber (ME4C) and transgastric RV inflow views at end-diastole. Spearman correlation coefficients (r) were applied to test for associations between the imaging modalities. Results: The mean age was 65 years and 39% were male. All patients had ≥ moderate tricuspid regurgitation (TR), and a secondary/functional etiology was present in 89%. The median TAd and RV basal (RVd) diameters in the TTE-A4C view measured 37 mm [interquartile range (IQR), 34-44] and 43 mm (IQR, 40-51), respectively. The TTE-A4C TAd strongly correlated with the TEE-ME4C measurement (r=0.72), with an overestimation of 1 mm (IQR, ?2 to 4) by TEE (P<0.01). For RVd, the TTE-A4C measurement correlated moderately with the TEE-ME4C view (r=0.61), underestimating the RVd by ?1 mm (IQR, ?4 to 3.3) (P<0.01). No correlation was observed between TAPSE measured by TTE and TEE (r=0.22, P=0.13). Conclusions: Intra-operative TEE may reliably quantitate TA and RV size and geometry. The current findings are best interpreted as hypothesis-generating for future validative studies.