B6: Cardiovascular Mechanics II

QUANTIFICATION OF CHANGES IN BLOOD FLOW FLUID DYNAMICS IN LEFT VENTRICLES OF PORCINE HEARTS BEFORE AND AFTER MYOCARDIAL INFARCTION

Vivek Vasudevan1, Low Jia Jun1, Sarayu Parimal2, Smita Sampath2, Choon-Hwai Yap1

1National University of Singapore, Singapore;
2Merck Research Laboratories, Singapore

Myocardial infarction (MI) is the leading cause of heart failure among cardiovascular diseases MI leads to changes to the heart’s stroke volume, beating rate, and ejection fraction, leading to drastic changes to the fluid dynamics These fluid dynamics changes are incompletely understood, partly due to the lack of longitudinal subject-specific data before and after the disease Understanding these changes can improve our understanding of the disease, and help us fine tine diagnostic techniques, the timing of intervention, and inspire new treatments 

In this study, MI was induced through permanent left circumflex ligation in two porcine subjects Multipleslice Cine MR imaging was performed before, one week after, and four weeks after the procedure on the same subjects, providing longitudinal subjectspecific data In each scan, 25 images of the heart were captured per cardiac cycle The LV geometry was digitally reconstructed and the radial motion of the LV wall from the centroid, as well as LV torsion was described with a mathematical model Dynamic mesh CFD simulations were performed to quantify the LV fluid mechanics 

The scan results showed that the infarcted heart had a significantly enlarged LV chamber, with a faster heart rate and lower ejection fraction Vorticity dynamics was drastically enhanced after MI, where the primary vortex rings generated several secondary vorticity structures via its interaction with the walls, leading to an elevated wall shear stress The wall pressures of infarcted heart was almost twice higher than those observed in the pre-surgery heart, suggesting that additional cardiac work was done to supply sufficient inflow and outflow in the infarcted heart, most likely to overcome additional energy losses of enhanced vorticity dynamics

In conclusion, significant alterations in the fluid dynamics features were observed from before to after myocardial infarction, including enhanced vorticity dynamics, wall shear

Organised by

Endorsed by

 

        Supported by
 

 

                          
     

       

                             
           
 

        Supporting Media