Performance Testing of the Modified Electrocardiogram Lead Placement

July 19, 2026 updated by: Hansu Bae

Performance Testing of the Modified Electrocardiogram Lead Placement in Patients Undergoing General Anesthesia

During general anesthesia for surgery, doctors use an electrocardiogram (ECG)-a simple heart monitor-to check for problems like poor blood flow to the heart or irregular heartbeats. Normally, ECG stickers (called electrodes) go on both shoulders and the left side of the belly, right outside the heart area, to get clear readings.

But for shoulder surgery, these spots are in the way of the operation, so doctors often place them elsewhere, like on the breastbone instead of the shoulder. This can give fuzzy or wrong results, missing key changes in the patient's heart-good or bad-during surgery.

To fix this and better watch heart health in shoulder surgery patients, this study tests different ECG sticker spots: the usual ones, the common backup (like on the breastbone), and a new idea-placing them near both temples. Researchers hope to find which setup gives the most accurate heart readings to keep patients safer.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Background and Rationale Electrocardiogram (ECG) monitoring is essential during general anesthesia to assess heart rate, arrhythmias, and myocardial ischemia, alongside blood pressure. Standard Lead II, derived from limb leads placed on the torso (both clavicles below and left anterior superior iliac spine, outside the heart boundary), aligns best with the heart's electrical axis for accurate rhythm and ischemia detection. However, in shoulder surgeries like arthroscopic rotator cuff repair, surgical incisions overlap these sites, forcing electrode relocation (e.g., to the sternum instead of the shoulder). This inward shift distorts ECG signals, potentially missing normal or abnormal heart changes during surgery. To address this, modified Lead II placements are needed for reliable cardiac surveillance in shoulder surgery patients.

Study Overview This prospective, single-group interventional study evaluates the performance of two modified ECG Lead II configurations compared to the standard during general anesthesia for non-shoulder surgeries (to simulate placement feasibility). The modifications test alternative sites for the left shoulder electrode: sternum center (modified Sternum-Chest Lead II, mSC2) versus temple (modified Temple-Chest Lead II, mTC2). Left-side versions are assessed post-induction in supine position; right-side versions post-surgery. Outcomes focus on ST segment morphology similarity (visual and quantitative) to ensure modified leads maintain diagnostic accuracy without artifacts.

Methods Summary Eligible adults (19-65 years) scheduled for general anesthesia in non-shoulder sites undergo standard monitoring (ECG, NIBP, SpO2) per institutional protocols. After induction and hemodynamic stabilization, three ECG configurations are recorded simultaneously using Vital Recorder software (VitalDB, Republic of Korea) for at least 10 noise-free waves: (1) Standard Lead II; (2) Left mSC2 (sternum, right shoulder, left iliac spine); (3) Left mTC2 (left temple, right shoulder, left iliac spine). Post-surgery, right-side mSC2 and mTC2 are added. Recordings capture preoperative ST segment status (normal/abnormal). Blinded assessors (two researchers, third for ties) evaluate ST similarity visually; quantitative area differences use R/RStudio.

Statistical Considerations Sample size (n=84, 10% dropout) is calculated via McNemar test for paired comparisons, stratified by ST status (normal: 38 pairs; abnormal: 46 pairs), yielding 80% power at $\alpha=0.05$ based on pilot data. Analysis: Stratified McNemar for agreement; R for area differences.

Safety and Ethics Modifications involve brief additional recordings with no added risk beyond standard care. IRB-approved (Dongguk University Ilsan Hospital); informed consent obtained. Data anonymized (case numbers); stored securely for 3 years per regulations.

Study Type

Interventional

Enrollment (Estimated)

84

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Dongkyu Lee, MD. Ph.D
  • Phone Number: 080-10-6431-4217
  • Email: entopic@naver.com

Study Locations

  • South Korea
    • Gyeonggi-do
      • Goyang-si, Gyeonggi-do, South Korea, 10326
        • Recruiting
        • Dongguk University Il-san Hospital
        • Contact:
        • Contact:
      • Goyang-si, Gyeonggi-do, South Korea, 10326
        • Not yet recruiting
        • Dongguk University Ilsan Hospital
        • Contact:
          • Hansu Assistant professor, MD.
          • Phone Number: 080-10-6326-1641
          • Email: hsbae81@gmail.com

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adult male and female patients aged 19 to 65 years scheduled for surgery under general anesthesia.
  • Patients scheduled for surgery in areas that do not affect ECG electrode placement (e.g., abdomen, head, face, lower limbs).
  • Patients with normal or abnormal ST segment changes confirmed on preoperative ECG.

Exclusion Criteria:

  • Patients who do not consent to the study.
  • Patients with implanted pacemakers.
  • Patients with a history of heart or lung surgery.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: All Participants
All enrolled patients (n=84) undergoing general anesthesia without restrictions on ECG lead placement receive simultaneous ECG monitoring with three lead configurations: standard Lead II (baseline), left-side modified sternum-chest Lead II (mSC2), and left-side modified temple-chest Lead II (mTC2) post-induction. Right-side versions are added post-surgery. This single arm tests ST segment similarity across methods to improve intraoperative cardiac monitoring accuracy
Device: Standard
Standard ECG Lead II monitoring: Three electrodes placed on both clavicles below and left anterior superior iliac spine (outside heart boundary). Recorded simultaneously post-induction for at least 10 noise-free waves using Vital Recorder software to establish baseline ST segment morphology during general anesthesia."
Other Names:
  • mSC2
  • mTC2
Device: mSC2
Modified Sternum-Chest Lead II ECG (mSC2): Electrode relocated to sternum center (replacing left shoulder), with right shoulder and left anterior superior iliac spine. Left-side version recorded post-induction; right-side post-surgery. Assesses ST segment similarity to standard for accurate ischemia detection in anesthesia.
Device: mTC2
Modified Temple-Chest Lead II ECG (mTC2): Electrode relocated near temple (replacing left shoulder), with right shoulder and left anterior superior iliac spine. Left-side version recorded post-induction; right-side post-surgery. Evaluates ST segment morphology match to standard to enhance cardiac monitoring reliability.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percentage of participants for whom each modified Lead II configuration demonstrates superior visual similarity to the Standard Lead II
Time Frame: Periprocedural
This measure evaluates and compares which of the two modified Lead II configurations (Left modified Temple-Chest Lead II [Lt-mTC2] vs. Left modified Sternum-Chest Lead II [Lt-mSC2]) aligns more accurately with the Standard Lead II. To ensure objectivity, two blinded researchers will independently compare the ECG waveform shapes and determine which modified lead shows superior visual similarity to the Standard Lead II. In cases of disagreement or tie, a third researcher will re-evaluate the waveforms for the final decision. Evaluators will be strictly blinded to the identity of the specific leads being assessed.
Periprocedural

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percentage of participants for whom each right-side modified Lead II configuration demonstrates superior visual similarity to the Standard Lead II
Time Frame: Periprocedural
This measure evaluates and compares which of the two right-side modified Lead II configurations (Right modified Temple-Chest Lead II [Rt-mTC2] vs. Right modified Sternum-Chest Lead II [Rt-mSC2]) aligns more accurately with the Standard Lead II post-surgery. Two blinded researchers will independently compare the ECG waveform shapes and determine which right-side modified lead shows superior visual similarity to the Standard Lead II. In cases of disagreement or tie, a third researcher will re-evaluate the waveforms for the final decision. Evaluators will be strictly blinded to the identity of the specific leads.
Periprocedural
Mean difference in ST segment amplitude between modified Temple-Chest Lead II (mTC2) and Standard Lead II
Time Frame: Periprocedural
The quantitative difference in ST segment amplitude (measured in millimeters or millivolts) will be compared between the mTC2 configuration and the Standard Lead II. Waveform data will be processed using R and RStudio programs to calculate the absolute amplitude differences. A paired t-test will be performed to analyze the statistical agreement and determine if significant differences exist between the two leads.
Periprocedural
Mean difference in ST segment amplitude between modified Sternum-Chest Lead II (mSC2) and Standard Lead II
Time Frame: Periprocedural
The quantitative difference in ST segment amplitude (measured in millimeters or millivolts) will be compared between the mSC2 configuration and the Standard Lead II. Waveform data will be processed using R and RStudio programs to calculate the absolute amplitude differences. A paired t-test will be performed to analyze the statistical agreement and determine if significant differences exist between the two leads.
Periprocedural

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Hansu Bae

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 25, 2026

Primary Completion (Estimated)

December 17, 2026

Study Completion (Estimated)

November 5, 2027

Study Registration Dates

First Submitted

November 15, 2025

First Submitted That Met QC Criteria

July 19, 2026

First Posted (Actual)

July 22, 2026

Study Record Updates

Last Update Posted (Actual)

July 22, 2026

Last Update Submitted That Met QC Criteria

July 19, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • DUIH IRB 2025-12-018

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

No plan to share individual participant data to protect participant privacy.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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