Systolic Anterior Motion of Mitral Valve Subchordal Apparatus: A Rare Echocardiographic Pattern in Non-Obstructive Hypertrophic Cardiomyopathy
Bibliographic record
Abstract
Systolic anterior motion (SAM) of the mitral valve or chordate is one characteristic seen in hypertrophic cardiomyopathy (HCM) either in obstructive or non-obstructive phenotypes. More often than not, the obstruction is caused by valvular rather than chordal SAM. We describe the role of echocardiography in identifying the actual anatomical location of the mitral valve apparatus involved in SAM and in assessing consequent left ventricular outflow tract (LVOT) obstruction in an otherwise asymptomatic patient. We report a case of a 29-year-old male admitted for an elective non-cardiac surgery, presenting with a cardiac murmur and left axis deviation with biventricular hypertrophy on electrocardiogram. On 2D transthoracic echocardiography (TTE), an asymmetrically hypertrophied left ventricle with systolic motion of anterior mitral valve was incidentally seen. Continuous wave Doppler assessment across the LVOT showed some gradient of obstruction (peak gradient: 9 mm Hg). Transesophageal echocardiography (TEE) demonstrated a redundant anterior mitral valve with the subchordal apparatus mainly causing SAM and confirmed the gradient obtained on TTE, with a mild degree, yet non-significant, degree of LVOT obstruction (mean gradient: 10 mm Hg) documented. Because of this finding, patient was cleared for surgery. Management was deemed conservative with emphasis on close surveillance for signs and symptoms attributable to development of significant LVOT obstruction in patients with HCM. To our knowledge, this is the first reported case in our country of an echocardiographic pattern of systolic anterior motion primarily of the subchordal mitral valve apparatus causing some, though non-significant, degree of LVOT obstruction in HCM. Echocardiographic features such as asymmetric left ventricular hypertrophy and presence of some LVOT obstruction caused primarily by subchordal apparatus could impact management in asymptomatic patients.
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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 | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.002 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| 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".