HOME SUBSCRIPTIONS CURRENT ISSUE PAST ISSUES CARDIOSOURCE SEARCH HELP FEEDBACK		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (36) Citing Articles via Google Scholar Google Scholar Articles by Sweeney, M. O. Articles by Prinzen, F. W. Search for Related Content PubMed PubMed Citation Articles by Sweeney, M. O. Articles by Prinzen, F. W.

A New Paradigm for Physiologic Ventricular Pacing

Michael O. Sweeney, MD^_*,_* and Frits W. Prinzen, PhD

^_* Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, the Netherlands.

View larger version (27K): [in a new window]   Figure 1 Effect of asynchronous ventricular activation on left ventricular (LV) pressure (upper tracing) and regional strain (lower tracings). During ventricular pacing, strain in different regions becomes asynchronous, as can be judged from the difference in onset of shortening (negative deflection of the curve). Asynchronous contraction causes reduction in ejection time and slows rates of increase and decrease of LV pressure and increases duration of isovolumic contraction (ic) and isovolumic relaxation (ir).

View larger version (27K): [in a new window]   Figure 2 Mechanisms of ventricular remodeling and progressive reduction in pump function during right ventricular apex pacing. For details, see text. P-V = pressure-volume.

View larger version (27K): [in a new window]   Figure 3 Paradigm for physiological pacing. For details, see text. BiV = biventricular pacing; LV = left ventricular; RV = right ventricular; RVA = right ventricular apex.

View larger version (24K): [in a new window]   Figure 4 Relationship between duration of mechanical asynchrony and heart failure development, as derived from various randomized clinical trials. This relationship indicates that attempts to avoid asynchronous activation may decrease the risk for developing heart failure most in patients requiring pacing for a longer time (children) and in patients with already-reduced pump function. A.U. = arbitrary units; RVA = right ventricular apex; Cum%VP = cumulative percent ventricular pacing.