Atrial Ionic Remodeling Induced by Atrial Tachycardia in the Presence of Congestive Heart Failure
Bibliographic record
Abstract
BACKGROUND: Atrial fibrillation (AF) and congestive heart failure (CHF) produce discrete forms of atrial ionic remodeling. The in vivo effects of atrial tachycardia (AT) remodeling are altered by CHF. This study evaluated underlying mechanisms at the level of ionic remodeling. METHODS AND RESULTS: We studied 4 groups of dogs: (1) unpaced controls (CTLs); (2) CHF caused by 2-week ventricular tachypacing (VTP, 240 bpm); (3) AT (400 bpm x 7 days); and (4) CHF+AT (2-week VTP with AT for the last 7 days). CHF and CHF+AT groups equally increased left atrial pressure. AF duration was increased in all paced groups. Effective refractory period (ERP) was decreased by 42% in AT versus CTL but by only 24% in AT+CHF versus CHF. CHF reduced L-type Ca2+ (I(Ca)), transient-outward (I(to)), and the slow delayed-rectifier (I(Ks)) currents while increasing the Na+-Ca2+ exchanger (I(NCX)) and not affecting the inward-rectifier (I(K1)) current. AT reduced I(to) and I(Ca) while increasing I(K1) and leaving I(Ks) unaltered. The addition of AT to CHF failed to alter I(to), I(Ks), or I(NCX) beyond the effect of CHF alone, decreased I(Ca) slightly compared with CHF alone, but had smaller effects on I(Ca) and I(K1) compared with AT alone. Thus, CHF+AT, as would occur in a CHF patient who develops AF, produced an ionic remodeling pattern different from that of CHF or AT alone and from what would have been predicted from additive effects of CHF and AT. CONCLUSIONS: The presence of CHF alters AT-induced ionic remodeling. Thus, the ionic remodeling caused by cardiac arrhythmias in the presence of cardiac pathology is not necessarily predictable from the effects of either alone, with important potential implications for understanding the pathophysiology of arrhythmias in the diseased heart.
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 | 0.000 | 0.000 |
| 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".