Is echo-guided optimization of biventricular devices time practical?

Abstract

The number of patients referred for cardiac resynchronization therapy (CRT) continues to grow. Nevertheless, 30% of CRT patients do not respond to this form of therapy, leaving few alternatives [ 1 Beshai J.F. Khunnawat C. Lin A.C. Mechanical dyssynchrony from the perspective of a cardiac electrophysiologist. Curr Opin Cardiol. 2008; 23: 447-451 Crossref PubMed Scopus (21) Google Scholar , 2 Reynolds M.R. Joventino L.P. Investigators. Relationship of baseline electrocardiographic characteristics with the response to cardiac resynchronization therapy for heart failure. Pacing Clin Electrophysiol. 2004; 27: 1513-1518 Crossref PubMed Scopus (31) Google Scholar , 3 Santos J.F. Parreira L. Madeira J. et al. Predictors of response to cardiac resynchronization therapy—importance of left ventricular dyssynchrony. Rev Port Cardiol. 2006; 25: 569-581 PubMed Google Scholar , 4 Van de Veire N.R. Bleeker G.B. De Sutter J. et al. Tissue synchronisation imaging accurately measures left ventricular dyssynchrony and predicts response to cardiac resynchronisation therapy. Heart. 2007; 93: 1034-1039 Crossref PubMed Scopus (49) Google Scholar ]. Atrioventricular optimization (AVO) has emerged as a promising tool for enhancing patient response to CRT. The premise of this technique is to improve diastolic filling by adjusting the AV-delay according to mitral valve inflow patterns. These timing intervals can impact CRT programming as nominal program settings for AV delays are typically very short and may in turn impair cardiac output by fusing early filling with atrial contraction or truncating atrial transport. The ability to program selective ventricular activation (e.g. V–V adjustments) is under further study. Published data suggest that there exists substantial individual variability, such that some patients will exhibit improvement in systolic function and stroke volume by correcting left ventricular dyssynchrony [ 5 Burri H. Sunthorn H. Shah D. Lerch R. Optimization of device programming for cardiac resynchronization therapy. Pacing Clin Electrophysiol. 2006; 29: 1416-1425 Crossref PubMed Scopus (39) Google Scholar , 7 Hardt S.E. Yazdi S.H. Bauer A. et al. Immediate and chronic effects of AV-delay optimization in patients with cardiac resynchronization therapy. Int J Cardiol. 2007; 115: 318-325 Abstract Full Text Full Text PDF PubMed Scopus (51) Google Scholar , 8 Ellenbogen K. Gold M. Meyer T. Primary results from the SmartDelay determined AV optimization: a comparison to other AV delay methods used in cardiac resynchronization therapy (SMART-AV) trial. Circulation. 2010; 122 (Supp.) Crossref Scopus (315) Google Scholar ]. An inherent limitation to this approach is the time spent to image and reprogram which is a precious commodity in clinical practice. The purpose of this report is to quantify the time spent performing echo-guided AV (AVO) and VV optimization (VVO).