Stroke work or systolic dP/dtmax to evaluate acute response to cardiac resynchronization therapy: are they interchangeable?
BACKGROUND
Cardiac resynchronization therapy (CRT) is characterized by a approximately 30% non-response. Invasive haemodynamic measurements are a traditional method to evaluate response to CRT. This study evaluates the correlation between acute changes in dP/dt(max) and Stroke Work (SW) during CRT.


METHODS
Thirty-four CRT candidates were haemodynamically evaluated by pressure-volume loop analysis during biventricular pacing.


RESULTS
Mean dP/dt(max) and SW at baseline were 854 +/- 198 and 5186 +/- 2349, and displayed an increase during pacing of 106 +/- 117 mmHg/s (13% +/- 14%) and 1303 +/- 3039 mL/mmHg (30% +/- 52%), respectively. No correlation was found between the percentage change in dP/dt(max) and SW (R = 0.06, P = ns). When defining response an augmentation of 10% relative to baseline for both parameters, 16 patients demonstrated an ambiguous response.


CONCLUSIONS
Although both parameters display an average increase during pacing, the change relative to baseline values of SW and dP/dt(max) is not related.
de Roest
Gerjan
G
Department of Cardiology, VU University Medical Center, 1081 HV Amsterdam, The Netherlands. gj.deroest@vumc.nl
Knaapen
Paul
P
Götte
Marco
M
Hendriks
Thijs
T
Allaart
Cor
C
de Cock
Carel
C
van Rossum
Albert
A
D000368:Aged; D002304:Cardiac Pacing, Artificial; D002311:Cardiomyopathy, Dilated / Q000503:physiopathology* / Q000628:therapy*; D005260:Female; D006352:Heart Ventricles / Q000294:innervation; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011446:Prospective Studies; D013223:Statistics as Topic; D013318:Stroke Volume / Q000502:physiology*; D013599:Systole / Q000502:physiology; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology / Q000628:therapy