Permanent Pacemaker Implantation in Patients With Isolated Persistent Left Superior Vena Cava From a Right-Sided Approach: Technical Considerations and Follow-Up Outcome
Bibliographic record
Abstract
BACKGROUND: Positioning a permanent pacing wire in patients with persistent left superior vena cava (PLSVC) to right ventricle often comes as on-table surprise. It is technically demanding and therefore most of operators prefer left-sided approach. We assessed technical challenges during pacemaker implantation, and their short- and long-term outcomes among patients with isolated PLSVC from a right-sided approach. METHODS: Thirty-one consecutive patients with isolated PLSVC and 93 patients with right superior vena cava (RSVC) were enrolled with syncope with sinus node dysfunction (SND) and atrioventricular (AV) block. Study was designed on the basis of nested case-control method, and therefore 1:3 proportions was the enrolment criteria to detect any difference as statistically significant as incidence of isolated PLSVC is low. RESULTS: Mean age of patients was 64.8 ± 10.5 years. SND was the most common indication (n = 55; 44%) followed by AV block (n = 47; 37%). Nineteen (20%) patients received tined pacing lead, while 105 (85%) had screwing lead. There was no significant difference in mean procedural time (25 ± 11 min vs. 23 ± 12 min; P = 0.24), mean fluoroscopic time (3.1 ± 2.2 min vs. 2.7 ± 2.1 min; P = 0.54), pacing parameters for atrial and ventricular leads, dislodgement rate (3.2% vs. 4.8%; P = 0.32) and follow-up duration (6.9 ± 1.3 years vs. 7.2 ± 1.1 years; P = 0.18) between two groups. Compared to patients with RSVC, those with PLSVC had alpha loop configuration for ventricular lead which was statistically significant (31 vs. 00; P = 0.002). CONCLUSIONS: Patients with PLSVC had alpha loop configuration for ventricular lead because of circuitous course via left mediastinum. Although pacemaker implantation through coronary sinus via isolated PLSVC from right sided-approach is technically challenging, it obtains good long-term results but needs frequent follow-up during the initial period.
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 | 0.001 |
| 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 | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".