Purpose: The aim of this study was to evaluate the effect of left ventricular aneurysm (LVA) volume and myocardial strain on left ventricular function in a rabbit model using real time three-dimensional echocardiographic imaging (RT-3DE) combined with two-dimensional speckle tracking imaging (2D-STI).
Methods: A rabbit model of LVA was prepared in 30 New Zealand rabbits by ligating the middle segment of the left anterior descending artery and the left circumflex artery (LVA group); 10 control rabbits underwent thoracotomy alone. Four weeks later, RT-3DE was performed to obtain data on left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), and LVA volume. The peak short-axis radial (SrR) and circumferential (SrC) strain rates were measured using 2D-STI technique.
Results: Compared with control rabbits, LVA group rabbits had significant left ventricular enlargement at the end-systolic and end-diastolic phases (both P < 0.05). LVEF, SrR-Systolic, and SrC-Systolic were significantly lower in the LVA group (all P < 0.05). Moreover, there were high correlations between LVEF and SrC-Systolic anterior wall, SrR-Systolic anterior wall, SrC-Systolic lateral wall, and SrR-Systolic lateral wall (r = -0.895, -0.887, -0.890, -0.891, respectively, all P < 0.05). Of note, LVA volume/LVEDV had the tightest inverse relationship with LVEF (r = -0.911, P < 0.01). Specifically, LVA volume/LVEDV >16% corresponded to LVEF <50%, and LVEF decreased 1.1% while LVA volume/LVEDV increased 1%.
Conclusions: LVA volume/LVEDV provided a sensitive indicator reflecting cardiac function with LVA. Measurement of various parameters using RT-3DE might be a useful means to evaluate cardiac function after LVA formation.
Keywords: aneurysm; cardiac imaging; strain.
© 2013, Wiley Periodicals, Inc.