The Accuracy of Cardiac Surface Conduction Velocity Measurements
Bibliographic record
Abstract
BACKGROUND: Conduction velocity (CV) is a measure of the health of myocardial tissue. It can be measured by taking differences in local activation times from intracardiac electrodes. Several factors introduce error into the measurement, among which ignoring the 3-dimensional aspect is a major detriment. OBJECTIVES: The purpose of this study was to determine if, nonetheless, there was a specific region where CV could be accurately measured. METHODS: Computer simulations of 3-dimensional ventricles with a realistic His-Purkinje system were performed. Ventricles also included a dense scar or diffuse fibrosis. RESULTS: A finer spatial sampling produced better agreement with true CV. Using an error limit of 10 cm/s as a threshold, measurements taken within a region <2 cm from the pacing site proved to be accurate. Error increased abruptly beyond this distance. The Purkinje system and tissue fiber orientation played equally major roles in leading to a surface CV that was not reflective of the CV propagation through the tissue. CONCLUSIONS: In general, surface CV correlates poorly with tissue CV. Only surface CV measurements close to the pacing site, taken with an electrode spacing of ≤1 mm, give reasonable estimates.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".