Patterns of decrease in multidirectional myocardial deformations in patients with fluctuating left ventricular...

Area of Science:

• Cardiology
• Echocardiography
• Cardiac Mechanics

Background:

• Left ventricular ejection fraction (LVEF) is a key measure of heart function.
• Longitudinal/circumferential/radial strain (LS/CS/RS) and strain rate (LSr/CSr/RSr) offer detailed insights into myocardial mechanics.
• Limited data exists on individual variations in strain parameters relative to fluctuating LVEF.

Purpose of the Study:

• To test the hypothesis that strain/strain rate and LVEF relationships exhibit non-linear, inflective patterns in individual hearts.
• To analyze the relationship between LS/CS/RS, LSr/CSr/RSr, and LVEF in patients with significant LVEF variability.

Main Methods:

• Utilized 2-D speckle tracking echocardiography data from 25 patients with fluctuating LVEF (ΔLVEF > 10%).
• Developed 'collective' and 'individual hearts' plots to model strain/strain rate versus LVEF relationships.
• Identified inflection points (IPs) and compared slope decrements above and below IPs.

Main Results:

• Collective plots showed linear LS/LSr decrease with LVEF ≥ 40% (IP at 40%) and constant values below 40%.
• Collective RS-LVEF relationship was sigmoid with IPs at 30% and 50% LVEF.
• Individual heart plots revealed no significant difference in slope decrements for LS/LSr-LVEF, and marginal difference for RS-LVEF.

Conclusions:

• While collective data suggests non-linear, inflective relationships between strain/strain rate and LVEF, this hypothesis was not confirmed in individual hearts.
• Further research with larger patient cohorts is necessary to validate the inflective nature of these relationships in individual patients.