Title: A New Paradigm in Cardiac Resynchronization Therapy?
Abstract: We have read the report by Sassone et al 1 Sassone B. Gambetti S. Bertini M. Beltrami M. Mascioli G. Bressan S. Fucà G. Pacchioni F. Pedaci M. Michelotti F. Bacchi Reggiani M.L. Padeletti L. Relation of QRS duration to response to cardiac resynchronization therapy. Am J Cardiol. 2015; 115: 214-219 Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar in a recent issue of the Journal. In a retrospective, single-center study, they observed that patients with left bundle branch block (LBBB) and QRS duration (QRSd) ≥178 ms who were treated by cardiac resynchronization therapy (CRT) had worse 6-month echocardiographic response and greater likelihood of adverse clinical events during a mean follow-up of 32 months compared with the rest of the LBBB population. This observation was interpreted that there is an upper limit of QRSd above which CRT benefit starts to decrease. Although the study can be viewed as a new paradigm in CRT, we would like to challenge authors' conclusions. Relation of QRS Duration to Response to Cardiac Resynchronization TherapyAmerican Journal of CardiologyVol. 115Issue 2PreviewLeft bundle branch block (LBBB) is the most reliable electrocardiographic predictor of responsiveness to cardiac resynchronization therapy (CRT). However, not all patients with LBBB will respond to CRT. Our aim was to investigate the interaction between QRS duration, LBBB-type morphology, and the responsiveness to CRT. We retrospectively analyzed electrocardiograms of 243 patients who underwent CRT implantation according to current clinical indications. A 6-month reduction of left ventricular end-systolic volume >15% was used to identify CRT responders. Full-Text PDF ReplyAmerican Journal of CardiologyVol. 115Issue 12PreviewWe thank Polasek et al for the opportunity to clarify some crucial points of our study.1 First, our study is observational and retrospective, thus needing further confirmation by prospective ad hoc studies as stated in the report. Obviously, given the retrospective and observational nature of the study, a control group cannot be expected unless we performed cardiac resynchronization therapy (CRT) device implantation disregarding the guidelines and it is not our case. Accordingly, we just commented on reported results, but we did not discourage CRT implantation in these patients. Full-Text PDF
Publication Year: 2015
Publication Date: 2015-04-20
Language: en
Type: letter
Indexed In: ['crossref', 'pubmed']
Access and Citation
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot