Effect of Primary Mitral Regurgitation on Left Ventricular Synchrony

Left ventricular remodeling in preclinical experimental mitral regurgitation of dogs

“…These alternations of the ECM are associated with increased LV compliance, myofiber slippage, myocyte hypertrophy and decreased total LV contraction. 2,4,14,25 Evidence supports local paracrine activation of many of these mechanisms, independent of hemodynamic relief from local wall stress. Hemodynamic stimuli set in motion a sequence of biochemical and inflammatory events in the LV interstitium that dictate the changes in the ECM.…”

“…cMRI has provided for determination of wall thickness and radius for each specific area of LV. 3e5, 24,25 The LV is often thought of as being unloaded because of the low-pressure regurgitation during systole; however, the increasing radius:LV thickness ratio actually increases the afterload. Based on cMRI in dogs, this stress is especially significant on the free wall of the LV apex.…”

“…The r:h ratio in the angle of the normal heart apex relative to the ventricular septum allows for this area of the normal heart to be thinner than the mid-wall. 5,24,25 This basic geometric principle is best illustrated at the apex of the right ventricle, where this acute angle allows a paperthin RV to contribute with minimal wall stress. Dilation of the LV apex results in a greater radius at this point in the LV, and magnifies focal wall stress even with modest increases in pressure.…”

Evaluating the Use of Spatial Covariance Structures in the Analysis of Cardiovascular Imaging Data

“…In an effort to incorporate the correlation among the readings, Denney et. al [11] divided the multiple readings into 3 different regions representing the different levels of the LV. They then performed separate analyses for each of the 3 regions defined by the level in the LV utilizing estimated covariance structures to incorporate in the analyses the interrelationships among the readings within a level.…”

Nonechocardiographic Imaging in Evaluation for Cardiac Resynchronization Therapy

“…The relevant indices from these methods are summarized in Table 2 38,52–67 . While some of these indices were shown to predict CRT response, the studied cohorts were small.…”