BACKGROUND: Recent clinical trials have challenged the clinical applicability of mechanical dyssynchrony in predicting cardiac resynchronisation therapy response. OBJECTIVE: To evaluate whether mechanical dyssynchrony has an additional benefit over QRS duration in predicting cardiac events in patients with systolic heart failure. METHODS: A total 167 patients admitted to hospital with heart failure (age 65+/-12, ejection fraction <35%) were followed up prospectively. Using tissue Doppler imaging (TDI), the time to peak systolic velocity during the ejection phase was measured in the basal septal and lateral segments. A temporal difference between the septal to lateral wall (Ts-l) of > or =65 ms was defined as a mechanical dyssynchrony. RESULTS: After 33 months of follow-up, 70 patients (41.9%) had cardiac events, including 42 (25.1%) with cardiac death. The event-free survival time decreased as Ts-l or QRS duration increased. Patients with QRS > or =120 ms had increased risks of cardiac events by multivariate Cox proportional hazard analysis (HR=1.88, 95% CI 1.07 to 3.29, p = 0.028). The presence of mechanical dyssynchrony also predicted an increased risk of cardiac events (HR=2.37, 95% CI 1.39 to 4.04, p = 0.002). Those with both electrical and mechanical dyssynchrony had a HR of 3.98 (95% CI 2.02 to 7.86, p <0.001) when compared with those with normal QRS duration and absence of mechanical dyssynchrony. The addition of mechanical dyssynchrony significantly improved the prognostic power of a model containing echocardiographic parameters and QRS duration. CONCLUSIONS: TDI-derived mechanical dyssynchrony is an important prognosticator and independently associated with QRS duration in predicting adverse events in patients with systolic heart failure.
BACKGROUND: Recent clinical trials have challenged the clinical applicability of mechanical dyssynchrony in predicting cardiac resynchronisation therapy response. OBJECTIVE: To evaluate whether mechanical dyssynchrony has an additional benefit over QRS duration in predicting cardiac events in patients with systolic heart failure. METHODS: A total 167 patients admitted to hospital with heart failure (age 65+/-12, ejection fraction <35%) were followed up prospectively. Using tissue Doppler imaging (TDI), the time to peak systolic velocity during the ejection phase was measured in the basal septal and lateral segments. A temporal difference between the septal to lateral wall (Ts-l) of > or =65 ms was defined as a mechanical dyssynchrony. RESULTS: After 33 months of follow-up, 70 patients (41.9%) had cardiac events, including 42 (25.1%) with cardiac death. The event-free survival time decreased as Ts-l or QRS duration increased. Patients with QRS > or =120 ms had increased risks of cardiac events by multivariate Cox proportional hazard analysis (HR=1.88, 95% CI 1.07 to 3.29, p = 0.028). The presence of mechanical dyssynchrony also predicted an increased risk of cardiac events (HR=2.37, 95% CI 1.39 to 4.04, p = 0.002). Those with both electrical and mechanical dyssynchrony had a HR of 3.98 (95% CI 2.02 to 7.86, p <0.001) when compared with those with normal QRS duration and absence of mechanical dyssynchrony. The addition of mechanical dyssynchrony significantly improved the prognostic power of a model containing echocardiographic parameters and QRS duration. CONCLUSIONS: TDI-derived mechanical dyssynchrony is an important prognosticator and independently associated with QRS duration in predicting adverse events in patients with systolic heart failure.
Authors: Yinbo Li; Christopher D Garson; Yaqin Xu; Patrick A Helm; John A Hossack; Brent A French Journal: Ultrasound Med Biol Date: 2011-06-02 Impact factor: 2.998
Authors: T Stan Gregory; Ehud J Schmidt; Shelley Hualei Zhang; Raymond Y Kwong; William G Stevenson; Jonathan R Murrow; Zion Tsz Ho Tse Journal: Ann Biomed Eng Date: 2014-09-16 Impact factor: 3.934