Beat-to-beat Evaluation of Atrial Pacing to Test Fluid Responsiveness

NCT07730242 | Not Yet Recruiting DMC

• 1 other identifier: NL-009695
• Study Type: interventional
• Target: 18
• Locations: 0 countries
• Sites: N/A

Brief Summary

The goal of this observational study is to learn whether atrial pacing-induced preload variation can identify fluid responsiveness in adult patients admitted to the intensive care unit after cardiac surgery. The main questions it aims to answer are: Can beat-to-beat atrial pacing induce measurable changes in stroke volume that predict fluid responsiveness? Do stroke volume changes measured by transthoracic echocardiography (LVOT VTI) and arterial waveform analysis identify patients who respond to a 500 mL fluid bolus? Researchers will compare fluid responders and non-responders, defined by a ≥10% increase in stroke volume after a 500 mL Ringer's lactate fluid bolus, to determine whether pacing-induced hemodynamic changes predict fluid responsiveness. Participants will: Undergo a standardized atrial pacing protocol (80-120 bpm in 10 bpm increments) before and after a routine 500 mL Ringer's lactate fluid bolus. Undergo transthoracic echocardiography and continuous arterial pressure monitoring during the pacing protocol. Have routine ICU hemodynamic data collected during their admission.

Conditions

Evaluate Whether Beat-to-beat Ramped Atrial Pacing is Related to Fluid Responsiveness in Postcardiac Surgery Patients

Keywords

fluid responsiveness; intensive care; atrial pacing; fluid bolus

Outcome Measures

Primary Outcomes (1)

• change in stroke volume measured before and after fluid administration in response to beat-to-beat atrial pacing.

  The main study parameter is the change in stroke volume measured before and after fluid administration in response to beat-to-beat atrial pacing. Stroke volume will be assessed using VTI of the LVOT via transthoracic echocardiography. This change will be compared between fluid responders (defined as a ≥10% increase in stroke volume following fluid administration) and non-responders to assess the predictive accuracy of the pacing protocol.

  On day 1

Secondary Outcomes (2)

• Arterial wave form analysis (via intra-arterial blood pressure monitoring) to compare the ability of wave form analysis to detect stroke volume changes.

  On day 1

• Complementation of the clinical findings with computer simulations (CircAdapt) in a comparable virtual cohort of patients

  On day 1

Study Arms (1)

Standard atrial pacing (80-120 bpm) before and after a routine 500 mL fluid bolus.

EXPERIMENTAL

No therapeutic intervention will take place. A pacemaker wire is routinely placed by the cardiac surgeon after the surgery, as part of the standard care that occurs with every surgery. As part of the study protocol, an atrial pacing protocol is performed, starting with pacing at 80 bpm, then increasing by 10 beats per minute until reaching 120 bpm, followed by a gradual decrease back to 80 bpm. This protocol is repeated after the administration of the 500 mL fluid bolus.

Procedure: Pacing protocol via routinely placed surgical pacemaker wire

Interventions

Pacing protocol via routinely placed surgical pacemaker wire PROCEDURE

A pacemaker wire is routinely placed by the cardiac surgeon after the surgery, as part of the standard care that occurs with every surgery. As part of the study protocol, an atrial pacing protocol is performed, starting with pacing at 80 bpm, then increasing by 10 beats per minute until reaching 120 bpm, followed by a gradual decrease back to 80 bpm. This protocol is repeated after the administration of the 500 mL fluid bolus. Additionally: As part of routine care, the intensivist frequently adjusts the pacemaker in this manner to test its function.

Standard atrial pacing (80-120 bpm) before and after a routine 500 mL fluid bolus.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Aged 18 years or older.
• Underwent CABG surgery, without concomitant valve surgery.
• Admitted to the ICU during the first postoperative day.
• Equipped with surgically placed temporary atrial pacemaker wire.
• Scheduled for a 500 mL bolus of balanced solution (Ringer's lactate) within the first two postoperative hours for clinical reasons.
• Able to provide preoperative consent at the outpatient clinic before the surgery takes place.
• Assessed by the attending intensivist as hemodynamically stable and (thereby) eligible for the study.

You may not qualify if:

• Presence of atrial fibrillation or other arrhythmias precluding atrial pacing.
• Absence of atrial pacemaker wire.
• Suspected cardiac tamponade or significant postoperative bleeding (e.g., \>400 mL blood loss in the first hour postoperatively).
• Use of extracorporeal life support (ECLS) during the observation period.
• Acute changes in vasopressor or inotrope dosage within the observation period.
• Significant changes in body position, ventilator settings, or pacing mode during the study protocol.
• Known contraindications to echocardiographic monitoring or arterial wave form analysis.

Sponsors & Collaborators

• Maastricht University Medical Center: lead

Central Study Contacts

Rob Driessen, MD, PhD

CONTACT

+31653821055; rob.driessen@mumc.nl

Bas van Bussel, MD, PhD

CONTACT

bas.van.bussel@mumc.nl

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 16, 2026
• First Posted: July 28, 2026
• Study Start (Estimated): January 1, 2027
• Primary Completion (Estimated): July 1, 2028
• Study Completion (Estimated): January 1, 2029
• Last Updated: July 28, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share