Volume 9, Issue 8, Pages S3-S13 (August 2012) Cardiac resynchronization therapy (CRT): Clinical trials, guidelines, and target populations  Cecilia Linde, MD, PhD, Kenneth Ellenbogen, MD, FHRS, Finlay A. McAlister, MD  Heart Rhythm  Volume 9, Issue 8, Pages S3-S13 (August 2012) DOI: 10.1016/j.hrthm.2012.04.026 Copyright © 2012 Heart Rhythm Society Terms and Conditions

Figure 1 Uncertainty of link between interventricular and intraventricular dyssynchrony, and QRS morphology. %DLC = extent of myocardium showing delayed longitudinal contraction; Inter-V = interventricular dyssynchrony; SD-12 = standard deviation of TP of the 12 left ventricular segments; TO-6base = maximal difference in TO between any two of six basal left ventricular segments; TP-6base = maximal difference in TP between any two of six basal segments; TP-sep-lat = difference between TP of septobasal and laterobasal segments. Reproduced with permission from Ghio S, Constantin C, Klersy C, et al. Eur Heart J 2004. Heart Rhythm 2012 9, S3-S13DOI: (10.1016/j.hrthm.2012.04.026) Copyright © 2012 Heart Rhythm Society Terms and Conditions

Figure 2 A: As shown in several clinical trials, for patients with moderate-to-severe heart failure (HF; New York Heart Association [NYHA] class III–IV), cardiac resynchronization therapy (CRT) provides very consistent improvements in NYHA functional class ranking, exercise capacity (measured by 6-minute hall walk distance), and peak oxygen consumption. B: As shown in several clinical trials, for patients with moderate-to-severe HF (NYHA class III–IV), CRT provides very consistent improvements in NYHA functional class ranking, exercise capacity (measured by 6-minute hall walk distance), and peak oxygen consumption. Heart Rhythm 2012 9, S3-S13DOI: (10.1016/j.hrthm.2012.04.026) Copyright © 2012 Heart Rhythm Society Terms and Conditions

Figure 3 MADIT-CRT—significant reduction in relative risk of sustaining a primary endpoint with CRT-D. CRT = cardiac resynchronization therapy; HF = heart failure. Adapted from Moss et al.20 Heart Rhythm 2012 9, S3-S13DOI: (10.1016/j.hrthm.2012.04.026) Copyright © 2012 Heart Rhythm Society Terms and Conditions

Figure 4 REVERSE—time to first hospitalization for management of congestive heart failure (HF) or to death from any cause was significantly delayed. CRT = cardiac resynchronization therapy. Adapted from Linde et al.19 Heart Rhythm 2012 9, S3-S13DOI: (10.1016/j.hrthm.2012.04.026) Copyright © 2012 Heart Rhythm Society Terms and Conditions

Figure 5 RAFT—primary endpoint. CRT = cardiac resynchronization therapy; ICD = implantable cardioverter-defibrillator. Adapted from Tang et al.21 Heart Rhythm 2012 9, S3-S13DOI: (10.1016/j.hrthm.2012.04.026) Copyright © 2012 Heart Rhythm Society Terms and Conditions

Figure 6 Composite clinical score from MIRACLE-ICD II. CRT = cardiac resynchronization therapy. Adapted from Abraham et al.14 Heart Rhythm 2012 9, S3-S13DOI: (10.1016/j.hrthm.2012.04.026) Copyright © 2012 Heart Rhythm Society Terms and Conditions

Figure 7 Composite clinical score from PROSPECT. Adapted from Chung et al.33 Heart Rhythm 2012 9, S3-S13DOI: (10.1016/j.hrthm.2012.04.026) Copyright © 2012 Heart Rhythm Society Terms and Conditions