Abstract 17708: Cardiac Nut-Cracker: Paroxysmal Left Main Coronary Compression by Inducible Pulmonary Trunk Dilatation in Pulmonary Hypertension
Bibliographic record
Abstract
Case Presentation: A 56yo woman with a 12-year history of idiopathic pHTN and severe RV dysfunction presented with worsening exertional angina (CCS III). Perfusion imaging demonstrated a large apical-septal defect, corresponding to an 80% eccentric stenosis of the LMCA on angiography ( Fig 1AB ) due to compression on ostium and shaft by a severely dilated pulmonary trunk ( Fig 1C ). Right heart catheterization revealed pulmonary artery pressures (PAPs) of 90/40/68mmHg. Operative risk for CABG was deemed prohibitive, thus the patient underwent high-risk PCI of the LMCA under IV conscious sedation. Initial angiography confirmed a patent LMCA with minimal longitudinal compression. Opening PAPs (102/37/64mmHg) with supplemental oxygen (FiO 2 /PaO 2 0.76/168mmHg) were similar to preop findings ( Fig 1D ). To replicate her symptomatology, supplemental oxygen was discontinued, resulting in rapid worsening of LMCA compression with severe reduction in LMCA cross-sectional area at room air conditions (FiO 2 /PaO 2 0.21/70mmHg), with corresponding suprasystemic PAP (122/44/73mmHg) ( Fig 1E) . Under IVUS guidance, a preselected stent was deployed producing complete LMCA patency without evidence of dynamic compression; minimal stent areas were unchanged at supraphysiologic and physiologic conditions: 19 vs 20mm 2 , FiO 2 0.73 vs 0.21 ( Fig 1F ). Discussion: LMCA stenosis from extrinsic compression of the vessel by an enlarged pulmonary artery is a rare etiology of acute coronary syndromes. Treatment options include PCI, CABG, reimplantation, or PA reduction plasty. While preop imaging clearly demonstrated LMCA compression by a dilated PA, during PCI true and dynamic severity of LMCA compression was revealed only under “normoxic conditions” (FiO 2 0.21). This paroxysmal “nut-cracker” phenomenon from inadvertent reversal of dynamic LMCA compression highlights the importance of normoxia in making the diagnosis of such anomalies in susceptible individuals with pHTN.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.004 | 0.002 |
| Insufficient payload (model declined to judge) | 0.010 | 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".