3D Echocardiographic Assessment of Epicardial Pacing After Cardiopulmonary Bypass.
- Conditions
- Disorder of Pacing Function
- Interventions
- Procedure: cardiac surgeryDevice: Right ventricular epicardial pacingDevice: 3D TEEDevice: Pacemaker lead
- Registration Number
- NCT02842762
- Lead Sponsor
- Suzanne Flier, MD
- Brief Summary
This study evaluates the usefulness of 3D echocardiography to guide pacemaker therapy in the operating room in cardiac surgical patients. Each patient will serve as his own control, following a paired design.
- Detailed Description
Cardiac surgical patients sometimes require temporary pacing wires to optimize cardiac function during weaning from cardiopulmonary bypass (CPB), and/or to treat hemodynamically significant brady-arrhythmias. The available patient series report that 8.6% to 23.9% of patient undergoing coronary artery bypass grafting (CABG) or valve surgery require temporary pacing at some time after CPB. The site of pacemaker wire placement seems to be a crucial determinant of cardiac output. In non-surgical patients isolated right ventricular (RV) pacing seems to induce electromechanical dyssynchrony of the RV and the left ventricle (LV). A normal ventricle in sinus rhythm displays a simultaneous contraction of all segments of the heart, so that regional minimal volume (i.e. maximal contraction) will occur at the same time. Isolated RV pacing seems to result in a left bundle branch type electrical activation sequence, with delayed contraction of some of the segments. The LV, but not the RV, seems to negatively affected by this state of dyssynchrony, resulting in decreased cardiac output. In surgical patients however, there is not such data available yet. Since isolated RV epicardial wire placement is still widely practiced in cardiac surgery, and in our own institution, we would like to study the effect of RV pacing on LV synchrony and LV output.
Again from studies in non-surgical patients receiving resynchronization therapy, we know that real-time three-dimensional (3D) echocardiography is very useful to pick up subtle changes in LV synchrony and thereby guide synchronization of ventricular contraction. However, to date the usefulness of real-time 3D echocardiography to guide pacemaker therapy in cardiac surgery is unknown. In the present feasibility study in cardiac surgical patients, we want to investigate the acute effects of isolated RV pacing on LV synchrony, and LV output.
Recruitment & Eligibility
- Status
- UNKNOWN
- Sex
- All
- Target Recruitment
- 40
- Adult patient scheduled to undergo elective cardiac surgery by means of full sternotomy and use of cardiopulmonary bypass
- Preoperative moderate to good LV function, ejection fraction > 30%
- Age > 18 yrs. old
- Preoperative sinus rhythm
- Pacemaker lead inserted by cardiac surgeon during surgery
- Underlying sinus rhythm after cardiopulmonary bypass before the end of surgery
- Able to understand written and verbal patient information
- Signed informed consent
- Emergency cardiac surgery
- Minimally invasive surgery
- Contraindication to TEE
- Redo surgery
- Hemodynamic instability after CPB (late exclusion criterium)
- No pacemaker lead inserted by cardiac surgeon (late exclusion criterium)
- No sinus rhythm during chest closure towards the end of surgery (late exclusion criterium)
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description Paced 3D TEE The patient is randomized to the order of measurements taken, and serves as his own control. * cardiac surgery * 3D TEE measurements of systolic dyssynchrony * right ventricular epicardial pacemaker lead (on) Non-paced cardiac surgery * cardiac surgery * 3D TEE measurements of systolic dyssynchrony * right ventricular epicardial pacemaker lead (off) Paced Right ventricular epicardial pacing The patient is randomized to the order of measurements taken, and serves as his own control. * cardiac surgery * 3D TEE measurements of systolic dyssynchrony * right ventricular epicardial pacemaker lead (on) Non-paced Pacemaker lead * cardiac surgery * 3D TEE measurements of systolic dyssynchrony * right ventricular epicardial pacemaker lead (off) Non-paced 3D TEE * cardiac surgery * 3D TEE measurements of systolic dyssynchrony * right ventricular epicardial pacemaker lead (off) Paced Pacemaker lead The patient is randomized to the order of measurements taken, and serves as his own control. * cardiac surgery * 3D TEE measurements of systolic dyssynchrony * right ventricular epicardial pacemaker lead (on) Paced cardiac surgery The patient is randomized to the order of measurements taken, and serves as his own control. * cardiac surgery * 3D TEE measurements of systolic dyssynchrony * right ventricular epicardial pacemaker lead (on)
- Primary Outcome Measures
Name Time Method Left ventricular systolic dyssynchrony index (SDI) Intraoperative, end of cardiac surgery (duration 10 minutes) For each segment of 16 segments excluding the apical cap in a standard 17-segment model, the time to reach regional minimal volume is calculated as a fraction of the total cardiac cycle (RR interval) and expressed as a percentage.10 The standard deviation of these measurements is defined as the SDI. Three-dimensional SDI is therefore the dispersion time to reach the minimum systolic volume (as recommended).
- Secondary Outcome Measures
Name Time Method Ventricular volumes and ejection fraction Intraoperative, end of cardiac surgery (duration 10 minutes) We will obtain a full volume 3D dataset and obtain end diastolic (EDV) and end systolic volume (ESV). By subtracting ESV from EDV we will obtain the ejection fraction (EF).
LVOT blood flow Intraoperative, end of cardiac surgery (duration 10 minutes) As a surrogate for cardiac output we will obtain the velocity time integral (VTI) across the left ventricular outflow tract (LVOT)
Presence and severity of mitral regurgitation Intraoperative, end of cardiac surgery (duration 10 minutes) From midesophageal position we will perform a transesophageal echocardiography (TEE) study to interrogate the mitral valve for the presence and severity of mitral regurgitation.
Trial Locations
- Locations (1)
University Hospital - London Health Sciences Centre
🇨🇦London, Ontario, Canada