Regional and temporal changes in left ventricular strain and stiffness in a porcine model of myocardial infarction
Autor: | Michael R. Zile, William M. Torres, Shayne C. Barlow, Francis G. Spinale, Heather Doviak, Julia Jacobs, Tarek Shazly |
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Rok vydání: | 2018 |
Předmět: |
Male
0301 basic medicine medicine.medical_specialty Time Factors Physiology Heart Ventricles Sus scrofa Myocardial Infarction Infarction Myocardial Reperfusion Injury Myocardial stiffness Speckle tracking echocardiography 030204 cardiovascular system & hematology Ventricular Function Left Ventricular Dysfunction Left 03 medical and health sciences 0302 clinical medicine Physiology (medical) Internal medicine medicine Animals Myocardial infarction Ventricular Remodeling business.industry Stiffness medicine.disease Myocardial Contraction Echocardiography Doppler Disease Models Animal 030104 developmental biology Cardiology medicine.symptom Cardiology and Cardiovascular Medicine business Left ventricular strain Research Article |
Zdroj: | American Journal of Physiology-Heart and Circulatory Physiology. 315:H958-H967 |
ISSN: | 1522-1539 0363-6135 |
Popis: | The aim of the present study was to serially track how myocardial infarction (MI) impacts regional myocardial strain and mechanical properties of the left ventricle (LV) in a large animal model. Post-MI remodeling has distinct regional effects throughout the LV myocardium. Regional quantification of LV biomechanical behavior could help explain changes in global function and thus advance clinical assessment of post-MI remodeling. The present study is based on a porcine MI model to characterize LV biomechanics over 28 days post-MI via speckle-tracking echocardiography (STE). Regional myocardial strain and strain rate were recorded in the circumferential, radial, and longitudinal directions at baseline and at 3, 14, and 28 days post-MI. Regional myocardial wall stress was calculated using standard echocardiographic metrics of geometry and Doppler-derived hemodynamic measurements. Regional diastolic myocardial stiffness was calculated from the resultant stress-strain relations. Peak strain and phasic strain rates were nonuniformly reduced throughout the myocardium post-MI, whereas time to peak strain was increased to a similar degree in the MI region and border zone by 28 days post-MI. Elevations in diastolic myocardial stiffness in the MI region plateaued at 14 days post-MI, after which a significant reduction in MI regional stiffness in the longitudinal direction occurred between 14 and 28 days post-MI. Post-MI biomechanical changes in the LV myocardium were initially limited to the MI region but nonuniformly extended into the neighboring border zone and remote myocardium over 28 days post-MI. STE enabled quantification of regional and temporal differences in myocardial strain and diastolic stiffness, underscoring the potential of this technique for clinical assessment of post-MI remodeling. NEW & NOTEWORTHY For the first time, speckle-tracking echocardiography was used to serially track regional biomechanical behavior and mechanical properties postmyocardial infarction (post-MI). We found that changes initially confined to the MI region extended throughout the myocardium in a nonuniform fashion over 28 days post-MI. Speckle-tracking echocardiography-based evaluation of regional changes in left ventricular biomechanics could advance both clinical assessment of left ventricular remodeling and therapeutic strategies that target aberrant biomechanical behavior post-MI. |
Databáze: | OpenAIRE |
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