Functional Similarity Between Electrograms Recorded from an Implantable Cardioverter Defibrillator Emulator and the Surface Electrocardiogram
Bibliographic record
Abstract
Clinical use of stored electrogram (EGM) configurations currently used in ICDs is limited. The hypothesis that EGMs recorded from electrodes on the ICD surface may improve diagnostic capabilities of the device was tested in the present study. The Buttons on Active Can Emulator (BACE), an ICD-sized device containing four button electrodes, was temporarily placed into a subcutaneous or submuscular left pectoral pocket in 16 patients during ICD implantation. Simultaneous recordings were obtained from the ECG lead II, bipolar EGMs using BACE electrodes, and a bipolar atrial EGM during sinus rhythm (SR), ventricular pacing (VP) at cycle lengths of 500 and 400 ms, and VT. Visible P waves were present in all patients during SR (n = 15), in 5 (33%) of 15 patients during VP, and none of the patients during VT (n = 4) using BACE EGMs and lead II. P and QRS amplitudes and the P:QRS ratio during SR in BACE EGMs were significantly lower than those in lead II. BACE EGMs showed prominent changes in QRS morphology and duration during VP and VT compared to SR, and the magnitude of QRS prolongation during VP was similar to that in lead II. Measurements of PR, QRS, and QT duration during SR showed good agreement between BACE EGMs and lead II. In conclusion, EGMs recorded from electrodes embedded on the ICD housing may potentially improve visual discrimination between supraventricular and ventricular arrhythmias. They also may be useful as a surrogate of the ECG for analysis and monitoring of different components of P-QRS-T complex.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".