Right ventricular transverse displacement increases following cardiac surgery: possibly compensating loss in tricuspid annular plane systolic excursion (TAPSE).

Right Ventricular (RV) output mostly derives from longitudinal shortening in normal hearts. However, following even uncomplicated cardiac surgery with preserved RV function a significant and sustained decrease in longitudinal contraction has been observed. How the RV compensates and sustains output in this setting remains unsettled. The aim of this study was to evaluate the RV contraction pattern by speckle tracking echocardiography to elucidate possible compensatory mechanisms mitigating the reduced RV longitudinal contraction after cardiac surgery. Thirty patients with normal preoperative ejection fraction and no valvulopathy underwent coronary artery bypass grafting (CABG) with the use of cardiopulmonary bypass (CPB). RV dedicated speckle tracking software measuring longitudinal and transverse displacement, as well as strain, was employed on transesophageal echocardiographic (TEE) images as part of the Right Ventricular Echocardiography in cardiac SurgEry (ReVERSE) study. Data was recorded at baseline (after anesthesia induction), immediately after CPB and upon chest closure. Tricuspid Annulus Plane Systolic Excursion (TAPSE) was reduced from 2.0 [1.6-2.5 cm] to 0.8 [0.6-11 mm] from baseline to after chest closure. RV longitudinal displacement was reduced from 6.1 [3.4-8.8 mm] to 2.9 [0.4-5.4 mm] at the same time-points. RV speckle tracking revealed concomitantly that transverse displacement of the free wall increased significantly from 1.2 [0-2.7 mm] at baseline to 5.4 [3.6-7.2 mm] after chest closure. RV speckle tracking strain did not change significantly. Increased transverse displacement likely compensates for reduction in RV longitudinal contraction following cardiac surgery and maintains cardiac output. The sustained output from the right ventricle was not related to an increased contractility.

Severe loss of right ventricular longitudinal contraction occurs after cardiopulmonary bypass in patients with preserved right ventricular output.

Assessment of right ventricular (RV) function is crucial since RV failure with a reduced cardiac output (CO) is associated with compromised outcome in cardiac surgery. Echocardiographic evaluation of RV function is commonly used, but a reduction in tricuspid annular plane systolic excursion (TAPSE) and tricuspid annulus tissue Doppler imaging (S') have been observed independently of clinical signs of RV failure. This has led to uncertainty of these variables' validity in cardiac surgery. To describe transesophageal echocardiographic (TEE) measures of RV function during coronary artery bypass graft surgery with detailed haemodynamic assessment using pulmonary artery catheter (PAC) measurements to describe "natural" changes in the absence of RV failure. We prospectively studied 30 patients with concomitant PAC and TEE measurements at four time-points, namely after: anaesthesia induction, sternotomy, cardiopulmonary bypass (CPB) and upon arrival in the intensive care unit. TAPSE and S' were significantly reduced by 43% (p < 0.0001) and 22% (p = 0.006), respectively after CPB without any change in stroke volume (SV). RV ejection fraction (RVEF), RV fractional area change (RVFAC) and global longitudinal strain (RV-GLS) remained unchanged. SV measured with 3D echocardiography correlated with PAC measured SV (r = 0.66[95% CI 0.50; 0.78], p < 0.0001), but 3D showed a minor, but statistically significant underestimation of SV (8.5 ml (95% CI 2.7 ml; 14 ml, p = 0.004). TAPSE and S' were both reduced after CPB despite maintained CO. RVFAC, RVEF and RV-GLS remained stable, however, these measures were unable to detect minor changes in SV. 3D-echocardiographyshowed a strong correlation with SV measured by thermodilution, but with a consistent underestimation of approximately 10%.

Tricuspid annular plane systolic excursion is significantly reduced during uncomplicated coronary artery bypass surgery: A prospective observational study.

OBJECTIVES: Longitudinal shortening constitutes most of the right ventricle (RV) contraction in the normal heart. However, after even uncomplicated cardiac surgery with preserved RV function a significant and sustained decrease in longitudinal contraction expressed as a reduction in tricuspid annular plane systolic excursion (TAPSE) has been observed. Why and exactly when this happens remains unsettled. The aim of this study was to evaluate the magnitude and timing of changes in TAPSE in relation to sternotomy, pericardial opening, cardiopulmonary bypass (CPB), and chest closure. METHODS: Fifty patients with normal preoperative ejection fraction and no valvulopathy, who underwent coronary artery bypass grafting with the use of CPB, were included. TAPSE was assessed using transthoracic echocardiography (TTE) at baseline and immediately after chest closure. Transesophageal echocardiography was performed at the following time points: after (1) anesthesia induction and transthoracic echocardiography; (2) sternotomy; (3) pericardiotomy; (4) completion of CPB; and (5) chest closure. RESULTS: TAPSE was significantly reduced to approximately half of its initial value in all patients (from 22 [95% confidence interval, 21-23 mm] after anesthesia induction to 9 [95% confidence interval, 8-10 mm] after chest closure). No change was seen after pericardiotomy. The most prominent reduction (30%-40%) was observed after weaning from CPB. An additional significant decrease of 13% to 16% was seen after chest closure. CONCLUSIONS: TAPSE was consistently reduced to approximately half of its initial value after uncomplicated coronary artery bypass grafting surgery. The reduction happened mainly after weaning from CPB, possibly reflecting conformational change of the RV.