title: Relation of left ventricular systolic dyssynchrony in patients with heart failure to left ventricular ejection fraction and to QRS duration.
abstract: Left ventricular (LV) systolic dyssynchrony is an important pathologic mechanism in patients with heart failure (HF). However, the prevalence of intraventricular dyssynchrony in patients with different LV ejection fractions (EFs) is unknown. This study evaluated 402 consecutive patients with HF (mean age 64.99 +/- 13.15 years, 72.4% men) and 120 healthy controls. Dyssynchrony indexes included the SD of the time to peak systolic velocity (Ts) in ejection phase in the 12-segmental model (Ts-SD) and the difference in Ts between basal septal and basal lateral segments (Ts-Septal-Lateral) using tissue Doppler imaging. Patients were divided into 3 groups according to LVEF (LVEF <20%, >20% to 35%, and >35% to 50%) and compared with healthy controls. Both indexes were significantly higher in all 3 LVEF groups compared with controls (p <0.0001). Based on the established cut-off values, systolic dyssynchrony was equally prevalent in all 3 LVEF groups and was 67%, 62%, and 55% using Ts-SD and 38%, 36%, and 35% using Ts-Septal-Lateral, respectively. However, the prevalence of systolic dyssynchrony was higher using Ts-SD than Ts-Septal-Lateral (chi-square = 94.43, p <0.001). Conversely, the prevalence of electrical dyssynchrony, defined as a >120-ms QRS duration, decreased significantly with increasing LVEF (44%, 35%, and 16%; chi-square 5.60, p <0.001). In conclusion, the prevalence of mechanical systolic dyssynchrony was independent of severity of LV systolic dysfunction. This may implicate the potential role of cardiac resynchronization therapy for those with LVEF of 35% to 50%, in particular when systolic dyssynchrony is present.
authors: Department of Medicine and Therapeutics, Division of Cardiology, Li Ka Shing Institute of Health Science, Institute of Vascular Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, People's Republic of China.
authors: Chin-Pang
authors: CP
authors: Chan
authors: Qing
authors: Q
authors: Zhang
authors: Gabriel Wai-Kwok
authors: GW
authors: Yip
authors: Jeffery Wing-Hong
authors: JW
authors: Fung
authors: Yat-Yin
authors: YY
authors: Lam
authors: Pui-Wai
authors: PW
authors: Lee
authors: Eugene B
authors: EB
authors: Wu
authors: Qing
authors: Q
authors: Shang
authors: Yujia
authors: Y
authors: Liang
authors: Cheuk-Man
authors: CM
authors: Yu
mesh_terms: D000368:Aged; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005260:Female; D054143:Heart Failure, Systolic / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*