Europace Advance Access published online on November 6, 2009
Europace, doi:10.1093/europace/eup347
CLINICAL RESEARCH
Value of right ventricular–left ventricular interlead electrical delay to predict reverse remodelling in cardiac resynchronization therapy: the INTER-V pilot study
1 Department of Cardiology, Bentivoglio Hospital, Azienda USL di Bologna, Via Marconi, 35 - 40010 Bentivoglio, Bologna, Italy; 2 Division of Cardiology, Casa di Cura Pederzoli, Peschiera, Verona, Italy; 3 Cardiovascular Institute, University of Ferrara, Ferrara, Italy; 4 Institute of Cardiology, University of Bologna, Bologna, Italy; 5 Department of Internal Medicine and Cardiology, University of Florence, Florence, Italy; 6 Cardiology Division, University of South Florida College of Medicine and Tampa Generale Hospital, Tampa, FL, USA
Aims: Few studies have systematically evaluated the value of intra-procedural parameters in predicting response to cardiac resynchronization therapy (CRT). We investigated whether intracardiac (electrogram) measurements of electrical delays between the positioned right ventricular (RV) and left ventricular (LV) leads at implantation could predict the mid-term CRT response.
Methods and results: Fifty-two patients underwent CRT implantation according to standard techniques and clinical indications. The RV–LV interlead electrical delay measured during spontaneous rhythm and the difference between the pacing-induced (
p) RV–LV interlead electrical delays measured during RV and LV pacing were defined intraoperatively using the electrical depolarizations registered at the ventricular leads on the device programmer. At 6 months, a reduction of LV end-systolic volume 
15% was used to define CRT responders. Responders (62%), when compared with non-responders, showed a higher proportion of ischaemic aetiology (P = 0.007) and a lower value of pRV–LV interlead electrical delay (22.1 ± 18.4 vs. 46.3 ± 15.0 ms, P = 0.0001). At multivariate analysis, the pRV–LV interlead electrical delay was the only independent predictor of response to CRT (P = 0.001). For such a parameter, the receiving operating characteristic curve analysis identified a cut-off value of 42 ms corresponding with the highest accuracy: sensitivity 90.6%; specificity 70%; positive and negative predictive value 83% and 82%, respectively. Conversely, no difference was ascertained between responders and non-responders when RV–LV interlead electrical delay was measured during spontaneous rhythm (76.1 ± 28.5 vs. 89.6 ± 21.2, P = 0.078).
Conclusion: Intraprocedural measuring of paced RV–LV interlead electrical delay obtained during RV and LV pacing predicts mid-term CRT response.
Key Words: Cardiac resynchronization therapy, Biventricular pacing, Heart failure, Pacing, Electrograms, Pacemaker lead position
* Corresponding author. Tel: +39 516 644 360, Fax: +39 516 644 383, Email: biagio.sassone{at}ausl.bologna.it
The Inter-Ventricular Lead Electrical Delay in Cardiac Resynchronization Therapy Study.
Manuscript submitted 10 August 2009. Accepted after revision 9 October 2009.