Diagnosis of Diastolic Dysfunction: Importance of Spectral Doppler Imaging
Bibliographic record
Abstract
In Response: Dr. Poelaert’s comments are of great interest to us and we agree that Doppler pattern can be influenced by loading condition. This is particularly true for transmitral valve velocity pattern, but the pulmonary venous flow is also affected by other factors, including age, heart rate, cardiac output, left ventricular systolic function, and left atrial function (1). In our study, the diagnosis of diastolic dysfunction was based not only on the mitral valve inflow but also on the pulmonary vein velocity signal as suggested by the Canadian Consensus recommendations for the measurement and reporting of diastolic dysfunction by echocardiography (2). The Doppler examination was performed, as we mentioned, “before pericardiotomy during a period of hemodynamic stability.” We routinely evaluate both pulmonary veins and have rarely encountered significant velocity differences before cardiac surgery Doppler signal from the right and left pulmonary veins are similar unless the Doppler signal intensity is attenuated because of improper positioning. The Doppler signal from the pulmonary vein can vary with mechanical ventilation, as we published before (1), but the systolic to diastolic ratio stayed the same. Klein et al. (3) observed discrepancies in velocities in up to 24% of patients with significant mitral regurgitation but in their series, the pulmonary flow was still abnormal in both veins. The use of a loading test (4) was not published when we collected the data and the use of tissue Doppler (5–8) was not a modality available on our transesophageal echocardiographic system at the time of the study. Furthermore, they are not yet part of the Canadian Consensus, which we used in the evaluation of diastolic dysfunction (2). We do agree however that they provide complementary and useful information on the appreciation of diastolic function. Our cardiologist, who was familiar with the use of tissue Doppler, did evaluate the mitral annular displacement in a semiqualitative fashion and could predict and confirm the type of diastolic abnormality based on visual inspection. This mode of evaluation, which is frequently discussed among “diastologists,” had not been formally validated at the time of the study, so we could not mention it in the methodology. André Denault, MD, FRCPC Francis Bernard, MD, FRCPC Pierre Couture, MD, FRCPC
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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 | 0.004 | 0.036 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.002 | 0.004 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.010 | 0.021 |
| Insufficient payload (model declined to judge) | 0.004 | 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".