RESUMO
<p><b>OBJECTIVE</b>The aim of the study is to evaluate the left ventricular (LV) dyssynchrony in chronic heart failure (HF) patients with normal and wide QRS duration.</p><p><b>METHODS</b>Time to peak velocity at peak systolic and early diastolic phase (Ts and Te) were determined in 12 segments of LV by echocardiography (GE Vivid 7) in 54 HF patients (28 with wide and 26 with normal QRS duration) and 15 normal controls to evaluate LV systolic and diastolic dyssynchrony. The risk factors related to LV dyssynchrony were also evaluated.</p><p><b>RESULTS</b>LV end systolic and diastolic volumes were significantly larger and 12 segmental mean Ts and maximal Te difference (Te-diff) were significantly higher in HF patients with wide QRS duration than HF patients with normal QRS duration. Using mean Ts >or= 182 ms as the cut-off value, systolic dyssynchrony was present in 46% HF patients with normal QRS and 71% HF patients with wide QRS. Using Te-diff >or= 79 ms as the cut-off value, diastolic dyssynchrony was seen in 58% HF patients with normal QRS and 89% HF patients with wide QRS. Combined systolic and diastolic dyssynchrony was seen in 31% HF patients with normal QRS and in 64% HF patients with wide QRS. Systolic dyssynchrony was significantly correlated to LV end systolic volume and diastolic dyssynchrony was correlated to end diastolic volume.</p><p><b>CONCLUSION</b>Percentage of LV dyssynchrony was significantly higher in HF patients with wide QRS, especially in HF patients with increased LV end systolic and diastolic volume.</p>