Apical Hypertrophic Cardiomyopathy
Bibliographic record
Abstract
To the Editor We have read with interest the excellent review on hypertrophic cardiomyopathy (HCM)1 and wish to comment on the apical variant of the disease listed in Table 4 but not discussed in the text. This variant can be found in 15% to 25% of Chinese and Japanese cohorts with HCM but only in 3% of American cohorts.2 The typical electrocardiography (ECG) shows the loss of septal Q waves, high QRS voltage, and repolarization abnormalities with deep T-wave inversion, especially in the leads closest to the apex—V4–V6.2 Because hypertrophy is confined to the apex, dynamic left ventricular outflow tract obstruction and systolic anterior motion of the anterior mitral valve leaflet are absent. The apical pulse may be sustained on palpation, and an S4 heart sound may be heard.2 There may not be a systolic murmur. It is reasonable to expect some degree of diastolic dysfunction and the possibility of relative apical ischemia as a result of the unbalanced wall thickness-to-vascular supply ratio.3 HCM apical variant may not have a totally benign prognosis with atrial fibrillation and myocardial infarction occurring in up to one-third of patients during long-term follow-up in the Western population.3,4 In addition, in patients with atrial fibrillation, HCM (including the apical variant) may increase the risks of systemic thromboembolism and the need for long-term anticoagulation.5,6 However, there are currently no data to suggest that the perioperative risks are increased in afflicted patients without a history of syncope, chest pain, dyspnea, or heart failure. Nonetheless, in a young asymptomatic patient, the bizarre ECG pattern first seen when intraoperative ECG electrodes are placed can be alarming and may even lead to the postponement of surgery or initiation of coronary vasodilator treatment. Alternatively, a preoperative ECG may lead one to suspect HCM. However, plain echocardiography may still miss apical HCM if the apex is not adequately examined.3 A microbubble contrast-enhanced echocardiography or cardiac magnetic resonance imaging, or both, may be required to differentially diagnose apical HCM, coronary artery disease, myocardial tumor, ventricular aneurysm, ventricular noncompaction, or endomyocardial fibrosis.3 Anthony M. H. Ho, MD, FRCPC, FCCP Department of Anesthesiology and Perioperative Medicine Queen’s University and Kingston General Hospital Kingston, Ontario, Canada [email protected] Po T. Chui, MBBS, FANZCA Alex P. W. Lee, MBChB, MRCP Song Wan, PhD, MD, FRCS Departments of Anaesthesia and Intensive Care, Medicine & Therapeutics, and Surgery The Chinese University of Hong Kong and Prince of Wales Hospital Hong Kong SAR, People’s Republic of China
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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 | 0.002 | 0.013 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.009 | 0.012 |
| Insufficient payload (model declined to judge) | 0.007 | 0.004 |
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".