Cardiac resynchronization therapy optimization by finger plethysmography.
OBJECTIVE
We tested a simple noninvasive method for cardiac resynchronization therapy (CRT) optimization using standard finger photoplethysmography (FPPG).


BACKGROUND
CRT can increase left ventricular cardiac output in patients with heart failure and ventricular conduction delay. Optimal therapy delivery depends on an appropriate AV delay. Multiple invasive and noninvasive methods have been attempted to identify patients and the best AV delay for CRT, but all suffer from a combination of high patient risk, cost, complexity, and low reproducibility.


METHODS
FPPG and invasive aortic pressure data were simultaneously collected from 57 heart failure patients during intrinsic rhythm alternating with very brief periods of pacing at 4 to 5 AV delays. After correcting data for artifacts, the median percentage responses for each AV delay were classified as positive, negative, or neutral compared to baseline (Wilcoxon rank test).


RESULTS
FPPG correctly identified positive aortic pulse pressure responses with 71% sensitivity (95% CI: 60-80%) and 90% specificity (95% CI: 84-94%) and negative aortic pulse pressure responses with 57% sensitivity (95% CI: 44-69%) and 96% specificity (95% CI: 91-98%). The magnitude of FPPG changes were strongly correlated with positive aortic pulse pressure changes (R(2) = 0.73, P < .0001) but less well correlated with negative aortic pulse pressure changes (R(2) = 0.43, P < .0001). FPPG selected 78% of the patients having positive aortic pulse pressure changes to CRT and identified the AV delay giving maximum aortic pulse pressure change in all selected patients.


CONCLUSIONS
FPPG can provide a simple noninvasive method for identifying significant changes in aortic pulse pressure with high specificity, including identifying patients in whom aortic pulse pressure increases with CRT and the AV delay giving the maximum aortic pulse pressure.
Butter
Christian
C
Department of Cardiology, German Heart Institute Berlin. c.butter@immanuel.de
Stellbrink
Christoph
C
Belalcazar
Andres
A
Villalta
Don
D
Schlegl
Michael
M
Sinha
Anil
A
Cuesta
Francisca
F
Reister
Craig
C
D001011:Aorta / Q000503:physiopathology*; D001283:Atrioventricular Node / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination / Q000379:methods; D002304:Cardiac Pacing, Artificial; D005260:Female; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D017156:Photoplethysmography / Q000379:methods*; D012680:Sensitivity and Specificity