Narrow complex tachycardia with alternating atrial activation: What is the Mechanism?
Bibliographic record
Abstract
Case Presentation: A 50-year male was referred for consideration of a redo ablation procedure. 2 years before this referral, he was diagnosed with an episode of pre-excited atrial fibrillation, and underwent an attempt at a left lateral pathway ablation. The index attempt with radiofrequency ablation did not eliminate the pathway and he was discharged on oral flecainide. The procedure was also complicated by a right-sided deep vein thrombosis and further attempts at a redo procedure were delayed. However, he developed recurrent episodes of palpitations 2 years after his index procedure. Hence, he was referred for a second attempt at ablation. His baseline 12-lead ECG did not show any evidence of manifest pre-excitation. During his EP study, pre-excitation was seen with atrial extrastimuli and with shorter intervals, a narrow complex tachycardia was induced (Figure [1](#fig-cap-0001)). However, the atrial activation appeared to alternate at times, despite the tachycardia being sustained. What is the mechanism of the alternating atrial activation?
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 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 | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.003 | 0.005 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.010 | 0.003 |
| Insufficient payload (model declined to judge) | 0.005 | 0.002 |
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".