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Aims: Biventricular (BiV) pacing was superior to right ventricular apical (RVA) pacing at extended follow-up in the Pacing to Avoid Cardiac Enlargement (PACE) trial. Early pacing-induced systolic dyssynchrony (DYS) might be related to mid-term result. However, it remains unknown whether early pacing-induced DYS can predict long-term reduction of left ventricular (LV) systolic function.Methods and Results: Patients with standard pacing indications and normal LV ejection fraction (LVEF) were randomized either to BiV (n = 89) or RVA (n = 88) pacing. Seventy-four patients in the RVA group and 72 in the BiV pacing group completed follow-up longer than 2 years. Serial echocardiography was performed with DYS assessed by tissue Doppler imaging, and the early pacing-induced DYS was defined as >33 ms by using standard deviation of the time to peak systolic velocity (Dyssynchrony Index) in a 12-segment model of LV at 1 month. There were 46 (32%) patients having early pacing-induced DYS that was more prevalent in the RVA pacing group than that in the BiV pacing group (50.7 vs. 12.3%, χ(2) = 25.1, P < 0.001) despite the similar DYS between the two groups at baseline (30 ± 13 vs. 26 ± 11 ms, P = 0.051). At a median follow-up of 4.8 years, patients developing early DYS had lower LVEF (53.2 ± 9.4 vs. 60.9 ± 8.0%, P < 0.001) and larger LV end-systolic volume (40.3 ± 23.7 vs. 29.3 ± 13.4 mL, P < 0.001) than those without DYS. Significant EF reduction (defined as ≥5%) occurred in 71.7% (33 in 46) of patients with DYS, but only in 30% (30 in 100) in those without DYS (χ(2) = 22.4, P < 0.001). Further analysis showed that both DYS at 1 month [odds ratio (OR): 3.113, P = 0.013] and RVA pacing (OR: 7.873, P < 0.001) independently predicted the deterioration of LV systolic function with pacing period of 4.8 years.Conclusion: Early pacing-induced DYS is a significant predictor of reduction of LV systolic function for long-term pacing, which could be prevented by BiV pacing at relatively long-period follow-up.Clinical Trial Registration: Centre for Clinical Trials number, CUHK_CCT00037 (URL: http://www.cct.cuhk.edu.hk/Registry/publictrialrecord.aspx?trialid=CUHK_CCT00037). [ABSTRACT FROM AUTHOR]

Aims: Biventricular (BiV) pacing was superior to right ventricular apical (RVA) pacing at extended follow-up in the Pacing to Avoid Cardiac Enlargement (PACE) trial. Early pacing-induced systolic dyssynchrony (DYS) might be related to mid-term result. However, it remains unknown whether early pacing-induced DYS can predict long-term reduction of left ventricular (LV) systolic function., Methods and Results: Patients with standard pacing indications and normal LV ejection fraction (LVEF) were randomized either to BiV (n = 89) or RVA (n = 88) pacing. Seventy-four patients in the RVA group and 72 in the BiV pacing group completed follow-up longer than 2 years. Serial echocardiography was performed with DYS assessed by tissue Doppler imaging, and the early pacing-induced DYS was defined as >33 ms by using standard deviation of the time to peak systolic velocity (Dyssynchrony Index) in a 12-segment model of LV at 1 month. There were 46 (32%) patients having early pacing-induced DYS that was more prevalent in the RVA pacing group than that in the BiV pacing group (50.7 vs. 12.3%, χ(2) = 25.1, P < 0.001) despite the similar DYS between the two groups at baseline (30 ± 13 vs. 26 ± 11 ms, P = 0.051). At a median follow-up of 4.8 years, patients developing early DYS had lower LVEF (53.2 ± 9.4 vs. 60.9 ± 8.0%, P < 0.001) and larger LV end-systolic volume (40.3 ± 23.7 vs. 29.3 ± 13.4 mL, P < 0.001) than those without DYS. Significant EF reduction (defined as ≥5%) occurred in 71.7% (33 in 46) of patients with DYS, but only in 30% (30 in 100) in those without DYS (χ(2) = 22.4, P < 0.001). Further analysis showed that both DYS at 1 month [odds ratio (OR): 3.113, P = 0.013] and RVA pacing (OR: 7.873, P < 0.001) independently predicted the deterioration of LV systolic function with pacing period of 4.8 years., Conclusion: Early pacing-induced DYS is a significant predictor of reduction of LV systolic function for long-term pacing, which could be prevented by BiV pacing at relatively long-period follow-up., Clinical Trial Registration: Centre for Clinical Trials number, CUHK&#95;CCT00037 (URL: http://www.cct.cuhk.edu.hk/Registry/publictrialrecord.aspx?trialid=CUHK&#95;CCT00037)., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)

Unlabelled: OBEJCTIVE: To compare left ventricular (LV) systolic performance and contractility in patients with heart failure and normal ejection fraction (HFNEF), compared with patients with heart failure and reduced ejection fraction (HFREF) and healthy subjects using newer echocardiographic techniques., Design: A case-control trial., Setting: University teaching hospital (tertiary referral centre)., Patients: Sixty healthy control subjects (53 ± 10 years), 112 patients with HFNEF (74 ± 12 years) and 175 patients with HFREF (67 ± 13 years)., Interventions: All underwent standard two-dimensional, Doppler and speckle-tracking echocardiography., Main Outcome Measures: Effective arterial (Ea) and LV end-systolic elastance (Ees), stress-corrected mid-wall shortening, preload recruitable stroke work, two-dimensional strain and torsion. Comparisons were adjusted for age, gender and body size., Results: Besides diastolic dysfunction, patients with HFNEF had impaired load-independent ventricular contractility with a progressive decrease of the corrected Ees from controls (2.9 ± 0.8 mm Hg/g) to HFNEF (2.2 ± 0.9 mm Hg/g) followed by HFREF (0.8 ± 0.3 mm Hg/g; all p<0.001). Ventricular-arterial coupling ratio was preserved in the HFNEF subgroup (normal 0.48 ± 0.09 vs 0.65 ± 0.16; p = NS) at the expense of both increased LV systolic stiffness and Ea. In addition, there was progressive decrease of global 2D circumferential, radial and longitudinal strain as well as torsion from normal, HFNEF to HFREF groups, even after adjustment for LV end-systolic wall stress or end-diastolic volume (all p<0.01). About 50% of patients with HFNEF had ≥ 1 global strain or torsion parameter depressed below normal after correction for LV end-systolic wall stress, with >85% falling below their corresponding stress-corrected mean., Conclusions: Impaired myocardial contractility is evident in many patients with HFNEF and this may contribute towards pathophysiology of HFNEF more than previously thought.