Cardiac resynchronization therapy: variations in echo-guided optimized atrioventricular and interventricular delays during follow-up.
BACKGROUND
Relatively few data are available on long-term echocardiographic optimization of atrioventricular (AV) and interventricular (VV) delay programming in cardiac resynchronization therapy (CRT). We assessed variations in optimized AV and VV delays during long-term follow-up.


METHODS
Thirty-seven consecutive heart failure patients received Doppler echocardiographic optimization of AV and VV delay within 48 hours from CRT device implantation, at 6 months and at 12 months (the last for the first enrolled 14 patients).


RESULTS
After implantation, median optimized AV delay was 100 ms (range, 45 ms); VV optimization led to simultaneous biventricular activation in 4 patients, left ventricular preactivation in 17 patients and right ventricular preactivation in 16 patients. At 12 months median AV delay decreased to 85 ms (23 ms) (P < 0.05 vs. baseline). With respect to previous assessment, VV delay variations > or =40 ms were observed in 41% of the patients at 6 months and in 57% of the tested patients at 12 months. A nonconcordance (by Kappa test) of optimized VV delays was found between each new assessment and the previous one. VV delay optimization was associated with significant (P < 0.001) increases in aortic velocity time integral both at baseline and during follow-up.


CONCLUSIONS
Echocardiographic optimization of AV and VV delay is associated with broad intraindividual variability during follow-up. A new assessment of optimized VV delays during long-term follow-up reveals a nonconcordance with previous values and provides increases in forward stroke volume.
Valzania
Cinzia
C
Institute of Cardiology, University of Bologna and Azienda Ospedaliera S.Orsola-Malpighi, Via Massarenti 9, 40138 Bologna, Italy. cinzia.valzania2@studio.unibo.it
Biffi
Mauro
M
Martignani
Cristian
C
Diemberger
Igor
I
Bertini
Matteo
M
Ziacchi
Matteo
M
Bacchi
Letizia
L
Rocchi
Guido
G
Rapezzi
Claudio
C
Branzi
Angelo
A
Boriani
Giuseppe
G
D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D013997:Time Factors; D016896:Treatment Outcome