Right Ventricular Echocardiography in caRdiac SurgEry

Study Overview
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Brief Summary
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Postoperative right ventricular (RV) dysfunction increases mortality and risk of cardiac failure after cardiac surgery substantially. A comprehensive understanding of this condition is paramount in order to achieve success in treatment and early diagnosis. This study has two main aims. Perioperative aim: To investigate correlations between changes in echocardiographic measurements and hemodynamic changes at baseline and following coronary artery bypass graft (CABG) surgery. Postoperative aim: To evaluate changes in haemodynamics and echocardiographic parameters during separate physiological interventions (increase in preload/afterload, oxygen fraction, pacing modes (AAI/DDD/VVI)).

Detailed Description
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Clinical procedure: For the operation standard procedures for anaesthesia, surgery and cardiopulmonary bypass will be used. This includes installment of a pulmonary artery catheter and performing a transesophageal echocardiography. For the purpose of this study additional TEE images and a transthoracic echocardiography (TTE) will be obtained in order to correlate different echocardiographic indices with haemodynamic measurements and investigate any differences between TTE and TEE measurements. Transthoracic echocardiography (TTE): Basic TTE will be performed after anaesthesia induction, before surgery commences and repeated immediately after arrival at the ICU. Image acquisitions from TTE: 2D apical 4-chamber view for right ventricular fractional area change (RVFAC) M-mode tricuspid annular plane systolic excursion (TAPSE). M-mode lateral mitral annular plane systolic excursion (MAPSE) measurements Transoesophageal echocardiography (TEE): After probe placement and before commencing surgery a TEE will be performed. The probe will be left in place during surgery for continuous imaging. Standard views used for patient treatment will be acquired in accordance with the requirements of the treating anaesthesiologist and surgeon. Additional views will be added in order to obtain standard 2D measures, M-mode measures, spectral doppler measures, myocardial doppler tissue imaging, strain and 3D measures of RV function. Measurements will be performed at different stages throughout surgery following a period of relative hemodynamic stability defined as: 1 minute of no more than 10 beats/min variation in heart rate, maximum variation of 10 mmHg in mean arterial pressure, maximum variation of 3 mmHg in central venous pressure and no change in administration of vasoactive drugs. If hemodynamic stability cannot be achieved an annotation comment will be entered. Time points for echocardiography: TEE will be performed at four different time points during and immediately after surgery: Stage 1: After induction of anaesthesia. Stage 2: After full sternotomy Stage 3: After completion of cardiopulmonary bypass Stage 4: Immediately after arrival at the ICU and will be repeated after each intervention Interventions Each intervention will be investigated separately and before each intervention the patient will return to hemodynamic baseline. Trendelenburg position for 5 minutes will be investigated. Following positive end-expiratory pressures will be investigated: 0 cm H2O, 5 cm H2O and 10 cm H2O. Following fractions of inspired O2 will be investigated: 0.5 and 1.0 for 10 minutes at each setting. Following pacemaker settings will be investigated: Atrioventricular pacing 10 bpm over the patients' intrinsic rhythm, atrial pacing 10 bpm over the patients' intrinsic rhythm, ventricular pacing 10 bpm over the patients' intrinsic rhythm

Official Title
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Response in Right Ventricular Function to Change in Afterload, Preload and Inspired Oxygen in Patients Undergoing Coronary Artery Bypass Graft Surgery

Conditions
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Right Ventricular Dysfunction

Intervention / Treatment
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* Other: Change in preload and afterload
* Other: Inspired oxygen
* Other: Pacemaker mode


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Elective coronary artery bypass graft patients Normal left ventricular function defined as LVEF over 50 % on TTE preoperatively Exclusion Criteria: Pre-existing right ventricular malformations Severe right ventricular impairment preoperatively Pre-existing non-sinus rhythm Pre-existing mitral valve stenosis or severe regurgitation Pre-existing pulmonary hypertension Pre-existing tricuspid valve stenosis or severe regurgitation Patients with contraindication to TEE probe placement such as oesophageal stricture or obstruction Patients with contraindication to Swan-Ganz catheter placement

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
Intervention Model: Single Group Assignment
Interventional Model Description: All patients will receive the same interventions
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: All patients<br>All patients will receive the treatment (CABG) and postoperatively three different interventions: Change in preload and afterload Change in inspired oxygen Change in pacemaker modes | Other: Change in preload and afterload<br>* Afterload: Three levels of positive end-expiratory pressure (PEEP) will be examined post-operatively: 0 cm H20, 5 cm H2O, 10 cm H2O Preload: Trendelenburg position for 5 minutes will be investigated<br>Other: Inspired oxygen<br>* Following fractions of inspired O2 will be investigated: 0.5 and 1.0 for 10 minutes respectively<br>Other: Pacemaker mode<br>* Following pacemaker settings will be investigated: Atrioventricular pacing 10 bpm over the patients' intrinsic rhythm, atrial pacing 10 bpm over the patients' intrinsic rhythm, ventricular pacing 10 bpm over the patients' intrinsic rhythm<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in right ventricular function during CABG assessed with TAPSE | Assessing the change in RV function during CABG surgery | During a standard CABG operation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Right ventricular function assessed with TAPSE after each intervention | Change in TAPSE after each intervention | Immediate postoperative period | 
| Change in cardiac output measured with Swan-Ganz during CABG | Cardiac output measured with the thermodilution technique | During a standard CABG operation | 
| Change in cardiac output measured with Swan-Ganz after each intervention | Cardiac output measured with the thermodilution technique | Immediate postoperative period | 
| Response in right ventricular function parameter S' to each intervention | Change in S' | Immediate postoperative period | 
| Response in right ventricular function parameter S' during CABG | Change in S' | During a standard CABG operation | 
| Response in right ventricular function parameter Tei index to each intervention | Change in Tei index | Immediate postoperative period | 
| Response in right ventricular function parameter Tei index during a standard CABG operation | Change in Tei index | During a standard CABG operation | 
| Response in right ventricular function parameter RVFAC to each intervention | Change in RVFAC | Immediate postoperative period | 
| Response in right ventricular function parameter RVFAC during a standard CABG operation | Change in RVFAC | During a standard CABG operation | 
| Response in left ventricular function parameter MAPSE to each intervention | Change in MAPSE | Immediate postoperative period | 
| Response in left ventricular function parameter MAPSE during a standard CABG operation | Change in MAPSE | During a standard CABG operation | 
| Response in right ventricular function parameter strain % to each intervention | Change in strain % | Immediate postoperative period | 
| Response in right ventricular function parameter strain % during a standard CABG operation | Change in strain % | During a standard CABG operation | 
| Response in right ventricular function parameter strain rate to each intervention | Change in strain rate | Immediate postoperative period | 
| Response in right ventricular function parameter strain rate during a standard CABG operation | Change in strain rate | During a standard CABG operation | 
| Response in right ventricular function parameter RV size to each intervention | Change in RV size | Immediate postoperative period | 
| Response in right ventricular function parameter RV size during a standard CABG operation | Change in RV size | During a standard CABG operation | 
| Response in right ventricular function parameter pulmonary artery flow velocity to each intervention | Change in flow velocity in pulmonary artery | Immediate postoperative period | 
| Response in right ventricular function parameter pulmonary artery flow velocity during a standard CABG operation | Change in flow velocity in pulmonary artery | During a standard CABG operation | 
| Response in right ventricular function parameter RVEF to each intervention | Change in RVEF measured with 3D echo | Immediate postoperative period | 
| Response in right ventricular function parameter RVEF during a standard CABG operation | Change in RVEF measured with 3D echo | During a standard CABG operation | 
| Response in right ventricular function parameter RVEF during CABG | Change in RVEF measured with 3D echo | Immediate postoperative period | 
| Change in cardiac output measured with Swan Ganz in response during a standard CABG operation | Following each intervention in the postoperative period cardiac output will be measured with the thermodilution technique. | During a standard CABG operation | 
| Change in cardiac output measured with Swan Ganz in response to each intervention | Following each intervention in the postoperative period cardiac output will be measured with the thermodilution technique. | Immediate postoperative period | 
| Change in hemodynamic pressures in response to each intervention | Following each intervention in the postoperative period hemodynamic pressures will be measured with the Swan Ganz catheter | Immediate postoperative period | 
| Change in hemodynamic pressures during a standard CABG operation | Following each intervention in the postoperative period hemodynamic pressures will be measured with the Swan Ganz catheter | During a standard CABG operation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Coronary artery bypass graft, Echocardiography