What does this research mean for the field?

Changes in the 3D geometry of the mitral apparatus, specifically increased tethering distance, strongly predict mitral regurgitation volume, whereas segmental left ventricular contractile dysfunction without dilation fails to produce significant regurgitation. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

What question did this study set out to answer?

This research seeks to differentiate between causes of segmental ischemic mitral regurgitation, focusing on left ventricular dysfunction and geometric distortion.

June 19, 2026Journal of the American College of Cardiology

Mechanism of ischemic mitral regurgitation with segmental left ventricular dysfunction: three-dimensional echocardiographic studies in models of acute and chronic progressive regurgitation

Q: What is the clinical evidence from this study?

Study design: Other. Population: Ischemic mitral regurgitation (n=14). Intervention: Left circumflex coronary ligation with permitted LV expansion vs. Restricted LV expansion. Primary outcome: Mitral regurgitation volume (r2 = 0.75 and 0.86).

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Key result

Increased mitral tethering distance strongly predicts MR volume in acute and chronic animal models.

r2 = 0.75 and 0.86
n=14

Why the study?

Proposed mechanisms for segmental ischemic mitral regurgitation—LV dysfunction versus geometric distortion by LV dilation—have practical therapeutic implications but are difficult to separate in patients.

Does geometric distortion by LV dilation cause ischemic mitral regurgitation more than segmental LV contractile dysfunction in animal models?

Population

Seven dogs with acute LCX ligation and seven sheep with LCX branch ligation

Comparison

Restricted LV expansion versus permitted LV expansion and remodeling

Design

Animal experimental study using acute and chronic models

Follow-up

Eight weeks

Authors

YOYutaka OtsujiKagoshima University MHMark D. HandschumacherCardiac Imaging NLNoah Liel‐CohenBen-Gurion University of the Negev

Discussion

Member takes

Implication

Separates LV dysfunction from dilation mechanisms in ischemic MR models; leaves open dominant driver in patients and requires clinical validation.

Key Points

This research seeks to differentiate between causes of segmental ischemic mitral regurgitation, focusing on left ventricular dysfunction and geometric distortion.
Utilized models in seven dogs and seven sheep with left circumflex coronary ligation to analyze acute and chronic left ventricular dysfunction.
Restricted left ventricular expansion initially, followed by observation of subsequent dilation and remodeling over eight weeks.
Employed three-dimensional echocardiography to quantify mitral geometry and regurgitation volume.
In the acute model, MR remained trace initially but increased to moderate with significant LV dilation (ejection fraction = 23 +/- 8%).
Chronic model showed MR increased from trace to moderate over eight weeks with LV dilation and shape changes.
The primary predictor of MR volume was the distance from papillary muscles to the anterior annulus, especially with medial and posterior shifts (r2 = 0.75 and 0.86).

Structured PICO

Does geometric distortion by LV dilation cause ischemic mitral regurgitation more than segmental LV contractile dysfunction in animal models?

Population

14 animal models (7 dogs, 7 sheep) undergoing left circumflex coronary ligation to evaluate mechanisms of ischemic mitral regurgitation over up to 8 weeks.

Intervention

Left circumflex coronary ligation to induce segmental ischemic LV dysfunction, with evaluation by 3D echocardiography

Comparator

Comparison between states of restricted LV expansion (without dilation) versus permitted LV expansion/remodeling (with dilation)

Outcome

Mitral regurgitation volume and mitral apparatus geometry quantified by 3D echocardiographysurrogate

Main Result

Effect estimate: r2 = 0.75 and 0.86

Ischemic mitral regurgitation is primarily driven by geometric distortion of the mitral apparatus due to LV dilation rather than segmental LV contractile dysfunction alone.

Cite This Study

Otsuji et al. (2001) studied Ischemic mitral regurgitation (n=14). Left circumflex coronary ligation with permitted LV expansion vs. Restricted LV expansion was evaluated on Mitral regurgitation volume (r2 = 0.75 and 0.86). Changes in the 3D geometry of the mitral apparatus, specifically increased tethering distance, strongly predicted mitral regurgitation volume in acute (r2=0.75) and chronic (r2=0.86) animal models.

synapsesocial.com/papers/6a355e04eae82deb18abe841 https://doi.org/10.1016/s0735-1097(00)01134-7

Topics

Mitral valve intervention

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Implication

Separates LV dysfunction from dilation mechanisms in ischemic MR models; leaves open dominant driver in patients and requires clinical validation.

Mechanism of ischemic mitral regurgitation with segmental left ventricular dysfunction: three-dimensional echocardiographic studies in models of acute and chronic progressive regurgitation

Discussion

Member takes

Implication

Key Points

Structured PICO

Main Result

Cite This Study

Topics

Mechanism of ischemic mitral regurgitation with segmental left ventricular dysfunction: three-dimensional echocardiographic studies in models of acute and chronic progressive regurgitation

Discussion

Member takes

Implication

Key Points

Structured PICO

Main Result

Cite This Study

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Topics

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