Left Atrial Reservoir Strain (LASr): Threshold for Elevated LV Filling Pressure
Left atrial reservoir strain (LASr, LA reservoir strain) is a parameter of left atrial deformation during its filling phase, used as a marker of elevated left ventricular filling pressure in the assessment of diastolic function.
Threshold Value
According to the clinical consensus of the American Society of Echocardiography (ASE) in collaboration with the European Association of Cardiovascular Imaging (EACVI) (2024), LASr < 18% is defined as the optimal threshold for detecting elevated LV filling pressure. In a large multicenter international study (322 patients), this value was established as the optimal cutoff point when using end-expiratory pulmonary capillary wedge pressure (end-expiratory PCWP) as the reference standard.
| Parameter | Value | Source |
|---|---|---|
| LASr, threshold for elevated LV filling pressure | < 18% | ASE/EACVI, 2024 |
Rationale for Threshold Selection
The consensus committee notes that the use of LASr < 18% provides an optimal balance of sensitivity and specificity in determining elevated filling pressure. An additional argument supporting this threshold is its validation across multiple centers.
LASr is considered in the context of assessing LV diastolic function, including in the setting of preserved ejection fraction, as an additional marker [clarification needed — a detailed algorithm for integration with classical diastolic parameters is not provided in the available excerpts].
Phases of Atrial Deformation
The dynamics of the left atrium are characterized by three phases: reservoir (reservoir), conduit (conduit), and contraction (contraction). Reservoir strain (LASr) corresponds to the atrial filling phase. Similar three phases (reservoir, conduit, contraction) are also described for right atrial deformation.
Frequently asked questions
What LASr threshold indicates elevated LV filling pressure?
LASr < 18% is the optimal cutoff point for detecting elevated LV filling pressure (ASE/EACVI, 2024).
On what basis is the LASr < 18% threshold established?
On a multicenter study of 322 patients using end-expiratory PCWP as the reference standard; this threshold provides an optimal balance of sensitivity and specificity.
What phases of left atrial deformation are distinguished?
Three phases: reservoir, conduit, and contraction. LASr reflects the reservoir phase.
Are the phase characteristics applicable to the right atrium?
Yes, right atrial dynamics are also characterized by three phases: reservoir, conduit, and contraction.