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)).
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
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
30
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
Following fractions of inspired O2 will be investigated: 0.5 and 1.0 for 10 minutes respectively
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
Rigshospitalet
Copenhagen, Capital Region, Denmark
Change in right ventricular function during CABG assessed with TAPSE
Assessing the change in RV function during CABG surgery
Time frame: During a standard CABG operation
Right ventricular function assessed with TAPSE after each intervention
Change in TAPSE after each intervention
Time frame: Immediate postoperative period
Change in cardiac output measured with Swan-Ganz during CABG
Cardiac output measured with the thermodilution technique
Time frame: During a standard CABG operation
Change in cardiac output measured with Swan-Ganz after each intervention
Cardiac output measured with the thermodilution technique
Time frame: Immediate postoperative period
Response in right ventricular function parameter S' to each intervention
Change in S'
Time frame: Immediate postoperative period
Response in right ventricular function parameter S' during CABG
Change in S'
Time frame: During a standard CABG operation
Response in right ventricular function parameter Tei index to each intervention
Change in Tei index
Time frame: Immediate postoperative period
Response in right ventricular function parameter Tei index during a standard CABG operation
Change in Tei index
Time frame: During a standard CABG operation
Response in right ventricular function parameter RVFAC to each intervention
Change in RVFAC
Time frame: Immediate postoperative period
Response in right ventricular function parameter RVFAC during a standard CABG operation
Change in RVFAC
Time frame: During a standard CABG operation
Response in left ventricular function parameter MAPSE to each intervention
Change in MAPSE
Time frame: Immediate postoperative period
Response in left ventricular function parameter MAPSE during a standard CABG operation
Change in MAPSE
Time frame: During a standard CABG operation
Response in right ventricular function parameter strain % to each intervention
Change in strain %
Time frame: Immediate postoperative period
Response in right ventricular function parameter strain % during a standard CABG operation
Change in strain %
Time frame: During a standard CABG operation
Response in right ventricular function parameter strain rate to each intervention
Change in strain rate
Time frame: Immediate postoperative period
Response in right ventricular function parameter strain rate during a standard CABG operation
Change in strain rate
Time frame: During a standard CABG operation
Response in right ventricular function parameter RV size to each intervention
Change in RV size
Time frame: Immediate postoperative period
Response in right ventricular function parameter RV size during a standard CABG operation
Change in RV size
Time frame: 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
Time frame: 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
Time frame: During a standard CABG operation
Response in right ventricular function parameter RVEF to each intervention
Change in RVEF measured with 3D echo
Time frame: Immediate postoperative period
Response in right ventricular function parameter RVEF during a standard CABG operation
Change in RVEF measured with 3D echo
Time frame: During a standard CABG operation
Response in right ventricular function parameter RVEF during CABG
Change in RVEF measured with 3D echo
Time frame: 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.
Time frame: 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.
Time frame: 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
Time frame: 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
Time frame: During a standard CABG operation
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