Echocardiographic quantification of left ventricular asynchrony predicts an acute hemodynamic benefit of cardiac resynchronization therapy.
OBJECTIVE
We sought to determine whether radial left ventricular (LV) asynchrony in patients with heart failure predicts systolic function improvement with cardiac resynchronization therapy (CRT).


BACKGROUND
We quantified LV wall motion by echocardiography to correlate the effects of CRT on LV systolic function with wall motion synchrony.


METHODS
Thirty-four patients underwent echocardiographic phase analysis of LV septal and lateral wall motion and hemodynamic testing before CRT. Phase relationships were measured by the difference between the lateral (Phi(L)) and septal (Phi(S)) wall motion phase angles: Phi(LS) = Phi(L) - Phi(S). The absolute value of Phi(LS) was used as an order-independent measure of synchrony: the absolute value Phi(LS) = the absolute value of Phi(L) - Phi(S).


RESULTS
Three phase relationships were identified (mean +/- SD): type 1 (n = 4; peak positive LV pressure [dP/dt(max)] 692 +/- 310 mm Hg/s; Phi(LS) = 5 +/- 6 degrees, synchronous wall motion); type 2 (n = 17; dP/dt(max) 532 +/- 148 mm Hg/s; Phi(LS) = 77 +/- 33 degrees, delayed lateral wall motion); and type 3 (n = 13; dP/dt(max) 558 +/- 154 mm Hg/s; Phi(LS) = -115 +/- 33 degrees, delayed septal wall motion, triphasic). A large absolute value of Phi(LS) predicted a larger increase in dP/dt(max) with CRT (r = 0.74, p < 0.001). Sixteen patients were studied during right ventricular (RV), LV and biventricular (BV) pacing. Cardiac resynchronization therapy acutely reduced the absolute value of Phi(LS) from 104 +/- 41 degrees (OFF) to 86 +/- 45 degrees (RV; p = 0.14 vs. OFF), 71 +/- 50 degrees (LV; p = 0.001 vs. OFF) and 66 +/- 42 degrees (BV; p = 0.001 vs. OFF). A reduction in the absolute value of Phi(LS) predicted an improvement in dP/dt(max) in type 2 patients for LV (r = 0.87, p = 0.005) and BV CRT (r = 0.73, p = 0.04).


CONCLUSIONS
Echocardiographic quantification of LV asynchrony identifies patients likely to have improved systolic function with CRT. Improved synchrony is directly related to improved hemodynamic systolic function in type 2 patients.
Department of Cardiology, University Hospital, Aachen, Germany.
Ole A
OA
Breithardt
Christoph
C
Stellbrink
Andrew P
AP
Kramer
Anil M
AM
Sinha
Andreas
A
Franke
Rodney
R
Salo
Bernhard
B
Schiffgens
Etienne
E
Huvelle
Angelo
A
Auricchio
D000368:Aged; D006348:Cardiac Surgical Procedures; D018592:Cross-Over Studies; D004452:Echocardiography; D004562:Electrocardiography; D005060:Europe / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000502:physiology / Q000601:surgery; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000601:surgery; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D016037:Single-Blind Method; D013223:Statistics as Topic; D013318:Stroke Volume / Q000502:physiology; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology*