Echo/Doppler-derived time intervals are able to predict left ventricular reverse remodeling after cardiac resynchronization therapy.
OBJECTIVE
We evaluated the predictive value of echo/Doppler derived indices, which reflect the duration of the isovolumic phases of the cardiac cycle, in identifying cardiac resynchronization therapy (CRT) responders.


RESULTS
In 105 patients before and 6 months after CRT the following echo/Doppler parameters were evaluated: myocardial performance index (MPI) as the sum of isovolumic contraction time (IVCT) and isovolumic relaxation time (IVRT) divided by ejection time; total isovolumic time (t-IVT) as the sum of IVCT and IVRT divided by the RR interval; and standard deviation of the time to systolic peak velocity (Ts-SD) as asynchrony index. After 6 months, patients were defined responders according to 15% left ventricle (LV) end-systolic volume reduction or more. At baseline, responders (53.3%) had higher t-IVT and MPI than nonresponders (0.30 +/- 0.06 versus 0.22 +/- 0.05, P < 0.0001 and 1.01 +/- 0.27 versus 0.73 +/- 0.19, P < 0.0001, respectively). Receiving operating characteristic curve analysis showed that both t-IVT (80.3% sensitivity and 83.7% specificity, cut-off = 0.263) and MPI (78.6% sensitivity and 81.6% specificity, cut-off = 0.84) could predict CRT response. Baseline t-IVT correlated well to end-systolic volume reduction (r = -0.56, P < 0.00001).


CONCLUSIONS
Echo/Doppler derived indices, describing physiologic abnormalities of the isovolumic contraction and relaxation phase, are able to predict CRT-induced reverse remodeling.
Department of Heart and Vessels, University of Florence, Florence, Italy.
Cristina M
CM
Porciani
Alessio
A
Lilli
Francesco
F
Cappelli
Alessia
A
Pappone
Alessandro Paoletti
AP
Perini
Paolo
P
Pieragnoli
Giuseppe
G
Ricciardi
Carmelo M
CM
Rao
Frits W
FW
Prinzen
Antonio
A
Michelucci
Luigi
L
Padeletti
D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial; D002908:Chronic Disease; D015150:Echocardiography, Doppler; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D015588:Observer Variation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling