Intraoperative Diastolic Function by TDI and STE

Study Overview
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Brief Summary
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This project aims at exploring measures of diastolic function perioperatively.

Detailed Description
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Perioperative echocardiographic quantification of myocardial function is of great importance in patient management and is increasingly being recommended intraoperatively in spite of some unresolved or under-explored issues. One such issue is the perioperative measurement of diastolic function. Diastolic dysfunction and diastolic heart failure - or as commonly referred to heart failure with preserved ejection fraction (HFpEF) - is responsible for some 35 to 50% of heart failures. Intraoperative measurements of diastolic function have a prognostic and management relevance for patients undergoing both cardiac and non-cardiac surgery. However, even recent guidelines on intraoperative transesophageal echocardiography (TEE) have neglected this topic, with the exception of the most recent, which briefly alluded to the role TEE can play in assessing diastolic function, but without addressing the issue of which measurements or views to use. The clinically prevalent echocardiographic view for assessment of intraoperative diastolic function by tissue Doppler imaging (TDI) is the midesophageal 4-chamber (ME 4C) TEE view. This view, which looks at the heart from the left atrium, is the standard view for evaluating intraoperative global cardiac performance. However, the Doppler angle for assessing diastolic performance is generally much greater than 20° and, as Doppler techniques are known to be angle dependent based on the Doppler equation, using this view may relevantly underestimate TDI velocities. Views from the apex of the heart (i.e. both the deep transgastric long axis view [dTG LAX] TEE view as well as the apical 4-chamber [AP 4C] transthoracic echocardiography (TTE) view) have a cosine angle towards the mitral annular plane excursion near zero, thereby allowing valid measurements according to the Doppler equation. However, TDI velocities are often - and potentially erroneously - reported from the ME 4C TEE view. The objective of this project is to address a number of important clinical topics regarding diastolic dysfunction in TEE. Two main objectives will be examined: Assess whether or not tissue doppler imaging (TDI) measurements of mitral annular plane velocities and systolic excursion in the midesophageal 4-chamber TEE view (ME 4C) significantly underestimate diastolic cardiac performance compared to the deep transgastric long axis TEE view (dTG LAX) due to intrinsic misalignment of the doppler beam. [i.e. is there a technological limitation?] Assess whether or not the difference in mitral annular plane velocities and systolic excursion between the ME 4C and dTG LAX will be underestimated using TDI compared to values derived from speckle tracking echocardiography (STE). [i.e. if there is a technological limitation, does STE show more consistency?] Two secondary objectives will be examined: Determine the influence of frame rates (temporospatial resolution) on STE-derived mitral annular velocities and systolic excursion by conducting STE measurement post cardiopulmonary Bypass (CPB) in atrially paced patients in the 1. midesophageal 4 chamber view (ME 4C) and 2. deep transgastric long axis view (dTG LAX). [i.e. if ST shows more consistency, what are its limitations?] Confirm the existence of and explore potential reasons (anesthesia, ventilation, TTE vs. TEE, Doppler alignment) for differences in mitral annular plane velocities and systolic excursion observed preoperatively (i.e. by cardiologists) and intraoperatively (i.e. by anesthetists, intensivists). Specifically, we will compare these values in four views: 1. apical 4-chamber view in TTE (AP 4C) preinduction, 2. apical 4-chamber view in TTE (AP 4C) postinduction, 3. midesophageal 4 chamber view (ME 4C) postinduction, and 4. Deep transgastric long axis view (dTG LAX) postinduction. [i.e. what is the relative contribution of the ignoring the misalignment in angulation compared to other intraoperative factors in explaining the observed underestimation of diastolic velocities and distances seen by cardiologists (AP 4C TTE view) and anesthetist's/intensivist's (ME 4C TEE view)?]

Official Title
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Assessment of Diastolic Function Using Intraoperative Transesophageal Echocardiography: Comparison of Mitral Annular Plane Velocity and Systolic Excursion Measured by Tissue Doppler Imaging vs. Speckle-Tracking

Conditions
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Echocardiography, Doppler, Echocardiography, Three-Dimensional, Echocardiography, Transesophageal, Echocardiography, Transthoracic

Intervention / Treatment
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* Other: TTE Apical 4 Chamber View
* Other: TEE dTG View
* Other: TEE ME 4C View


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ≥18 years undergoing cardiac surgery, and routinely receiving TEE for the surgical procedure, independent of the study. Exclusion Criteria: atrial flutter or fibrillation severe mitral calcification cancelled surgery unwilling or unable to provide consent

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Patients will receive a series of perioperative echocardiographical measurements by TTE as well as TEE prior to induction, postinduction, and post cardiopulmonary bypass
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: TTE Apical 4 Chamber View<br>Patients will receive TTE apical 4chamber echo examinations prior to induction and after induction | Other: TTE Apical 4 Chamber View<br>* We will measure a number of echocardiography parameters by TTE (apical 4 Chamber View) prior to and after induction<br>|
| Other: TEE dTG View<br>Patients will receive TEE deep transgastric echo examinations after induction and after cardiopulmonary bypass induction (paced at 80, 100, and 120 bpm) | Other: TEE dTG View<br>* We will measure a number of echocardiography parameters by TEE (dTG View) prior to cardiopulmonary bypass and after cardiopulmonary bypass (atrially paced at 80, 100, and 120 bpm)<br>|
| Other: TEE ME 4C View<br>Patients will receive TEE midesophageal 4chamber echo examinations after induction and after cardiopulmonary bypass induction (paced at 80, 100, and 120 bpm) | Other: TEE ME 4C View<br>* We will measure a number of echocardiography parameters by TEE (ME 4C View) prior to cardiopulmonary bypass and after cardiopulmonary bypass (atrially paced at 80, 100, and 120 bpm)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| mean early diastolic mitral annular plane velocity (E') | (E'lateral + E'medial)/2; by TDI and STE | immediately during echo exam while in the operating room; i.e. preinduction (TTE AP 4C), postinduction (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view), post-CPB (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| mean late (atrial) diastolic mitral annular plane velocity (A') | (A'lateral + A'medial)/2; by TDI and STE | immediately during echo exam while in the operating room; i.e. preinduction (TTE AP 4C), postinduction (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view), post-CPB (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view) | 
| mean early diastolic mitral annular plane velocity/mean late (atrial) diastolic mitral annular plane velocity (E'/A') | [(E'lateral + E'medial)/2] / [(A'lateral + A'medial)/2]; by TDI and STE | immediately during echo exam while in the operating room; i.e. preinduction (TTE AP 4C), postinduction (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view), post-CPB (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view) | 
| mean early diastolic mitral inflow velocity/mean early diastolic mitral annular plane velocities; (E/E') | E/[(E'lateral + E'medial)/2]; by doppler, TDI, and STE | immediately during echo exam while in the operating room; i.e. preinduction (TTE AP 4C), postinduction (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view), post-CPB (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view) | 
| Peak systolic mitral annular velocity (S') | by TDI and STE | immediately during echo exam while in the operating room; i.e. preinduction (TTE AP 4C), postinduction (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view), post-CPB (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view) | 
| Displacement by Mitral Annular Plane Systolic Excursion (MAPSE) | (MAPSEmedial + MAPSElateral)/2 | immediately during echo exam while in the operating room; i.e. preinduction (TTE AP 4C), postinduction (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view), post-CPB (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view) | 
| Displacement by Tricuspid Annular Place Systolic Excursion (TAPSE) | only laterally | immediately during echo exam while in the operating room; i.e. preinduction (TTE AP 4C), postinduction (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view), post-CPB (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view) | 
| Displacement of Mitral Annular Plane (by speckle-tracking software) | using tissue Motion annular displacement (TMAD) in Cardiovascular Ultrasound Quantification Software (QLAB) | immediately during echo exam while in the operating room; i.e. preinduction (TTE AP 4C), postinduction (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view), post-CPB (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view) | 
| Displacement of Tricuspid Annular Plane (by speckle-tracking software) | using tissue Motion annular displacement (TMAD) in Cardiovascular Ultrasound Quantification Software (QLAB) | immediately during echo exam while in the operating room; i.e. preinduction (TTE AP 4C), postinduction (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view), post-CPB (TTE AP 4C view, TEE ME 4C view, TEE dTG LAX view) | 
| 3D volumes of left ventricle | using 4-beat ECG-gated image acquisition | immediately during echo exam while in the operating room; i.e. postinduction (TEE ME 4C view), post-CPB (TEE ME 4C view) | 
| 3D volumes of right ventricle | using 4-beat ECG-gated image acquisition | immediately during echo exam while in the operating room; i.e. postinduction (TEE ME 4C view), post-CPB (TEE ME 4C view) |