Feasibility of Measuring Myocardial Performance Index of the Right Ventricle in Anesthetized Patients

Reduction in Postoperative Right Ventricular Echocardiographic Indices Predicts Longer Duration of Vasoactive Support After Cardiac Surgery

OBJECTIVES

To assess perioperative right ventricular (RV) echocardiographic indices and their relationship to vasopressor and inotropic support in cardiac surgical patients. The authors hypothesized that a reduction in echocardiographic parameters of RV function would be associated with a longer duration of vasopressor and inotropic support in the intensive care unit (ICU).

DESIGN

A prospective observational study.

SETTING

A quaternary care hospital affiliated with McGill University, Canada.

PARTICIPANTS

Adult patients undergoing elective cardiac surgery.

INTERVENTIONS

Transesophageal echocardiography and hemodynamics measurements with a pulmonary artery catheter were performed after induction of anesthesia (pre-cardiopulmonary bypass [CPB]) and at post-CPB.

MEASUREMENTS AND MAIN RESULTS

Echocardiographic measurements included anatomic M-mode tricuspid annular plane systolic excursion, fractional area change (FAC), tricuspid annulus peak systolic velocity (TAPSE), and myocardial performance index. The primary outcome was the duration of vasopressor and inotropic support in the ICU. Of the 122 patients who were enrolled in the study, 83 underwent coronary artery bypass graft surgery. At the end of the procedure, 94.3% of patients were supported with a vasopressor or inotrope. A reduction in post-CPB TAPSE was found in 88.2% (105) of patients, and 56.8% (63) of patients had a reduction in FAC. Patients with a post-CPB TAPSE below 17 mm and a post-CPB FAC below 35% required a longer duration of inotropic support in the ICU.

CONCLUSION

Patients with post-CPB TAPSE <17 mmHg require a longer duration of inotropic support in the ICU. From all measured RV echocardiographic indices, post-CPB FAC is an independent predictor of vasopressor and inotropic support. A reduction of post-CPB TAPSE and FAC in patients undergoing cardiac surgery is indicative of RV dysfunction requiring a longer use of vasopressor and inotropic support and potentially longer stay in the cardiovascular ICU.

Interchangeability of transthoracic and transesophageal echocardiographic right heart measurements in the perioperative setting and correlation with hemodynamic parameters

Reduction of right ventricular (RV) function after cardiac surgery has been shown to impact outcomes. Conventional indices for right ventricular dysfunction are validated using transthoracic echocardiogram (TTE) which has limited use compared to transesophageal echocardiogram (TEE) in the perioperative settings. The aim of this study was to assess the agreement of RV systolic function assessment with TEE compared to TTE and assess the association of echocardiographic parameter with hemodynamic indices of RV dysfunction. This was a single center prospective observational study in an academic institution. Fifty adult patients undergoing elective cardiac surgery were included. TTE, TEE and stroke volume measurements pre-cardiopulmonary bypass (CPB) and post-CPB were performed. The variables of interest were anatomical M-mode tricuspid annular plane systolic excursion (AMM-TAPSE), fractional area change (FAC), tricuspid annular velocity (S') and myocardial performance index (MPI). FAC and AMM-TAPSE measured at the mid-esophageal 4 chamber view had substantial agreement with the TTE acquired parameters (Lin's concordance correlation coefficient (CCC) = 0.76, 95%CI 0.59-0.86 and CCC = 0.85, 95%CI 0.76-0.91). S' was significantly underestimated by TEE (CCC = 0.07, 95%CI 0.04-0.19) and MPI showed moderate agreement (CCC = 0.45 95%CI 0.19-0.65). Despite the significant changes in echocardiographic parameters, there were no corresponding changes in stroke volume (SV) or pulmonary artery pulsatility index at the post-CPB period. TEE acquired FAC and AMM-TAPSE had substantial agreement with pre-operative TTE values and no significant differences between the pre-CPB and post-CPB period. Systolic RV echocardiographic parameters decreased post-CPB but this was not accompanied by significant hemodynamic changes.

Role of Echocardiography for the Perioperative Assessment of the Right Ventricle

Purpose of Review

This review aims to highlight the perioperative echocardiographic evaluation of right ventricular (RV) function with strengths and limitations of commonly used and evolving techniques. It explains the value of transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) and describes the perioperative changes of RV function echocardiographers should be aware of.

Recent Findings

RV dysfunction is an entity with strong influence on outcome. However, its definition and assessment in the perioperative interval are not well-defined. Moreover, values assessed by TTE and TEE are not interchangeable; while some parameters seem to correlate well, others do not. Myocardial strain analysis and three-dimensional echocardiography may overcome the limitations of conventional echocardiographic measures and provide further insight into perioperative cardiac mechanics.

Summary

Echocardiography has become an essential part of modern anesthesiology in patients with RV dysfunction. It offers the opportunity to evaluate not only global but also regional RV function and distinguish alterations of RV contraction.

Assessing Right Ventricular Function in the Perioperative Setting, Part I: Echo-Based Measurements

This article reviews transesophageal echocardiography-based assessment of perioperative right ventricular function and failure, including catheter-based methods, three-dimensional echocardiography, and their combination to make pressure-volume loops. It outlines right ventricular pathophysiology, multiple assessment methods, and their relationship to analogous transthoracic echocardiogram measurements. technologies used and developed for transthoracic or left ventricular assessment show significant limitations when applied to transesophageal assessment of the right ventricle. The article provides an overview of right ventricular assessment modalities that can be used in transesophageal echocardiography. Ultimately, clinicians must know limitations of measurements, synthesize information, and assess it in the clinical context.

Right Ventricular Longitudinal Strain In Left Ventricular Assist Device Surgery-A Retrospective Cohort Study

OBJECTIVES

Right ventricular (RV) failure is common after left ventricular assist device (LVAD) surgery and is associated with higher mortality. Measurement of longitudinal RV strain using speckle-tracking technology is a novel approach to quantify RV function. The authors hypothesized that depressed peak longitudinal RV strain measured by intraoperative transesophageal echocardiography (TEE) examinations would be associated with adverse outcomes after LVAD surgery.

DESIGN

Retrospective cohort study.

SETTING

Tertiary academic medical center.

PARTICIPANTS

Following Institutional Review Board approval, the authors retrospectively identified adult patients who underwent implantation of non-pulsatile LVAD. Exclusion criteria included inadequate TEE images and device explantation within 6 months for heart transplantation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The postoperative adverse event outcome was defined as a composite of one or more of death within 6 months, ≥14 days of inotropes, mechanical RV support, or device thrombosis. Intraoperative TEE images were analyzed for peak RV free wall longitudinal strain by two blinded investigators. Simple logistic regression was used to assess the relationship between adverse outcome and the mean of the strain measurements of the two raters. Agreement between the raters was assessed by intra-class correlation (0.62) and Pearson correlation coefficient (0.63). Of the 57 subjects, 21 (37%) had an adverse outcome. The logistic regression indicated no significant association between RV peak longitudinal strain and adverse events.

CONCLUSIONS

In this retrospective study of patients undergoing non-pulsatile LVAD implantation, peak longitudinal strain of the RV free wall was not associated with adverse outcomes within 6 months after surgery. Additional quantitative echocardiographic measures for intraoperative RV assessment should be explored.

Update on Perioperative Right Heart Assessment Using Transesophageal Echocardiography

Purpose of the review. This review aims to summarize recent findings relevant for perioperative 2- and 3-dimensional imaging of the right heart with transesophageal echocardiography. Special attention is given to developments that are likely to affect future approaches for prevention and therapy of perioperative right heart failure. Recent findings. Three-dimensional transesophageal echocardiography techniques are becoming more common for the evaluation of anatomy, volumes, and functional indices. Summary. Right heart failure continues to contribute to morbidity and mortality in the context of cardiothoracic surgery. The advent and widespread clinical use of innovative tools permitting more accurate echocardiographic assessment of the right heart will open the door to renewed interest in novel therapeutic strategies.