Changes in Left Ventricular Global and Regional Longitudinal Strain During Right Ventricular Pacing
Bibliographic record
Abstract
BACKGROUND: Our study aimed to demonstrate the short-term impacts of right ventricular apical pacing (RVAP) and right ventricular septal pacing (RVSP) on left ventricular (LV) regional longitudinal strain (RLS) and global longitudinal strain (GLS) in patients with preserved ejection fraction (EF). LV strain and functions may be altered by RVAP. RVSP might be a better alternative. The detrimental effect of right ventricular (RV) pacing may be mediated by regional LV impairment. METHODS: Sixty-two patients indicated for permanent pacemaker implantation and preserved LV systolic function were included. Dual chamber pacemakers were implanted in all patients. Patients were divided into two groups according to RV lead position: group A (RVAP, n = 32) and group B (RVSP, n = 30). Patients were examined at baseline and after 6 months of implantation for LV systolic functions, global and regional strain by echocardiography and 2D speckle tracking echocardiography. RESULTS: Paced QRS duration was significantly shorter in group B compared to group A patients (P = 0.02). Regarding ventricular strain, there was no statistically significant difference between both groups at baseline measurements in comparisons of GLS, relative apical longitudinal strain (rALS) and RLS (P > 0.05). In contrast, there was statistically significant difference between both groups in results of GLS (P = 0.01) at 6 months. In addition, RLSs in septal, apical and rALS were affected after 6 months with P values of 0.02, 0.03 and 0.03, respectively. CONCLUSION: RVAP appears to worsen GLS more than RVSP, and the resultant decrease in apical strain is most correlated region to decrease in GLS.
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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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) | 0.000 | 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".