New Mechanical Markers for Tracking the Progression of Myocardial Infarction

The mechanical propertiesof soft tissues can often be stronglycorrelated with the progression of various diseases, such as myocardialinfarction (MI). However, the dynamic mechanical properties of cardiactissues during MI progression remain poorly understood. Herein, weinvestigate the rheological responses of cardiac tissues at differentstages of MI (i.e., early-stage, mid-stage, and late-stage) with atomicforce microscopy-based microrheology. Surprisingly, we discover thatall cardiac tissues exhibit a universal two-stage power-law rheologicalbehavior at different time scales. The experimentally found power-lawexponents can capture an inconspicuous initial rheological change,making them particularly suitable as markers for early-stage MI diagnosis.We further develop a self-similar hierarchical model to characterizethe progressive mechanical changes from subcellular to tissue scales.The theoretically calculated mechanical indexes are found to markedlyvary among different stages of MI. These new mechanical markers areapplicable for tracking the subtle changes of cardiac tissues duringMI progression.

Automated summary

In this study, the rheological responses of cardiac tissues at different stages of myocardial infarction (MI) were investigated using atomic force microscopy-based microrheology. It was found that all cardiac tissues exhibited a universal two-stage power-law rheological behavior at different time scales. The power-law exponents discovered in the experiment can capture an inconspicuous initial rheological change, making them suitable as markers for early-stage MI diagnosis.