Diagnostic value of cardiac computed tomography angiography in patients with left bundle branch block and abnormal single-photon emission computed tomography findings
Bibliographic record
Abstract
BACkGRouND:The presence of septal perfusion defect on myocardial perfusion single-photon emission computed tomography (SPECT) in patients with known left bundle branch block (LBBB) can present a major diagnostic dilemma.METhoDS: Thirty-nine patients with known LBBB underwent both SPECT and coronary computed tomography angiography (CCTA), a median of 65 days after SPECT.Patients underwent SPECT; CCTA was performed on the basis of abnormal SPECT and presence of clinical symptoms.Exclusion criteria included a history of myocardial infarction, previous coronary artery bypass surgery or percutaneous coronary intervention.RESuLTS: Of the study population (n=39), 22 (56%) patients were female and the mean (± SD) age was 63±13 years; all patients were known to have LBBB diagnosed by electrocardiogram.SPECT results showed 24 (61%) patients had a reversible septal defect and 15 (39%) had a fixed septal defect.CCTA revealed that 27 (69%) patients had normal coronary artery or nonobstructive coronary artery disease (CAD); only 12 (31%) had abnormal coronary artery (>50% luminal stenosis).There was no relationship between patterns of SPECT perfusion abnormalities and CCTA results.CoNCLuSIoN: The presence of abnormal SPECT in patients with LBBB did not necessarily indicate the presence of CAD.Approximately 70% of patients with LBBB and abnormal SPECT had normal CCTA.The authors strongly believe CCTA must be considered the first noninvasive test in patients without history of CAD and LBBB.Normal CCTA excludes CAD, but patients with obstructive CAD >50% on CCTA will benefit from conventional coronary angiography.
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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 | 0.006 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 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".