Predicting response to cardiac resynchronization therapy with cross-correlation analysis of myocardial systolic acceleration: a new approach to echocardiographic dyssynchrony evaluation.
BACKGROUND
We tested the ability of cross-correlation analysis of myocardial systolic acceleration (XCA), a new marker of dyssynchrony based on tissue Doppler echocardiography, to predict long-term outcome of cardiac resynchronization therapy (CRT) and to discriminate between control patients and patients with dyssynchrony.


METHODS
XCA was performed by off-line analysis of digitally stored myocardial velocity curves in 44 patients treated with CRT and followed for 13 +/- 2 months. We tested the ability of preimplant XCA to identify long-term responders to CRT (defined by a decrease in left ventricular end-systolic volume > 15%). Dyssynchrony findings were compared between CRT responders and 83 age-matched control patients with narrow QRS complexes and different levels of systolic cardiac dysfunction. XCA was compared with conventional dyssynchrony analysis based on differences in time-to-peak myocardial velocity.


RESULTS
XCA was able to discriminate between long-term responders and nonresponders to CRT (area under the curve [AUC] = 0.66), but not significantly better than conventional analysis (AUC = 0.58). XCA showed large differences between the control groups and the CRT group (P < .01 for all), and had a higher discriminatory ability between normal controls and responders to CRT than conventional analysis (AUC = 0.95 vs 0.75, P < .01).


CONCLUSIONS
XCA significantly improves the assessment of intraventricular dyssynchrony, and dyssynchrony by this method is associated with positive long-term response to CRT.
Department of Cardiology, Gentofte University Hospital, Copenhagen, 65 Niels Andersens Vej, Hellerup, Denmark. thueolsen@post.tele.dk
Niels Thue
NT
Olsen
Rasmus
R
Mogelvang
Christian
C
Jons
Thomas
T
Fritz-Hansen
Peter
P
Sogaard
D000368:Aged; D000465:Algorithms; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012044:Regression Analysis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000517:prevention & control*