Assessment of interventricular dyssynchrony by real time three-dimensional echocardiography: an in vitro study in a porcine model.
BACKGROUND
Loss of synchronous contraction between or within the right and left ventricle (RV, LV) leads to adverse ventricular function. We used real time three-dimensional echocardiography (RT3DE) for evaluation of severity of interventricular dyssynchrony and function in a porcine heart model.


METHODS
Six fresh in vitro porcine hearts were used to create a controlled model of LV and RV dyssynchrony using two sets of pulsatile pumps. Synchronized and dyssynchronized pump settings were used with two different dyssynchronized settings: LV filled first and RV filled first.


RESULTS
There was good correlation between actual measurement and RT3DE for interventricular time difference (r = 0.95, P < 0.0001) and stroke volume (SV) for LV and RV (0.89, 0.85; P < 0.0001, respectively). RT3DE data showed a small but significant underestimation for actual volume (P < 0.05). The intra- and interobserver variabilities are 2.9 +/- 1.5% and 3.1 +/- 5.4% for LV and RV SVs, and 1.7 +/- 2.4% and 2.2 +/- 3.2% for time differences by RT3DE. There was significant difference in RV SV between synchrony and dyssynchrony when the RV filled first (P < 0.05), but not in other groups. The same pattern was found in RT3DE derived SVs (synchrony versus dyssynchrony with RV filled first, P < 0.05).


CONCLUSIONS
There is no compromise in LV SV during interventricular dyssynchrony; but RV SV was significantly diminished when the RV filled first. RT3DE is a feasible, robust and reproducible method to identify interventricular dyssynchrony and to evaluate ventricular SVs.
Zheng
Minjuan
M
Oregon Health & Science University, Portland, Oregon 97239-3098, USA.
Li
Xiaokui
X
Zhang
Pengyuan
P
Shentu
Weihui
W
Ashraf
Muhammad
M
Imanbayev
Galym
G
Streiff
Cole
C
Ge
Shuping
S
Sahn
David J
DJ
D000465:Algorithms; D000818:Animals; D003199:Computer Systems; D004195:Disease Models, Animal; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D066298:In Vitro Techniques; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000000981:diagnostic imaging*; D018497:Ventricular Dysfunction, Right / Q000150:complications / Q000000981:diagnostic imaging*