Prevalence of Left Ventricular Diastolic Asynchrony in Patient with Systolic Heart Failure

Background: To study the occurrence of left ventricular (LV) diastolic asynchrony in patients with systolic heart failure (HF) and its relationship to diastolic function regardless of QRS duration. Recent work has demonstrated that intraventricular asynchrony is a common finding in patients with systolic heart failure. Little attention has been paid to diastolic asynchrony in patients with systolic heart failure. We have therefore decided to determine the extent to which patients with systolic heart failure have evidence of diastolic asynchrony and whether or not diastolic asynchrony is correlated with diastolic dysfunction. Patients and Methods: Tissue Doppler echocardiography was performed in 50 HF patients (LV EF=23 ± 8%). Diastolic and systolic asynchrony was determined by tissue synchronization imaging using a 6 basal, 6 mid-segmental model. Systolic and diastolic asynchrony were assessed by the maximal difference in time to peak systolic and early diastolic velocities between any two of 12 LV segments, and the standard deviation of time to peak systolic and early diastolic velocities of the 12 LV segments. Results: The mean ± SD maximal difference in time to peak systolic velocity (controls: 17.2± 9.6 ms versus narrow QRS: 66.7 ± 38.0 ms versus wide QRS: 76.5± 34.6 ms, both P < 0.05 versus controls) and in standard deviation of time to peak systolic velocity of 12 LV segments (controls: 15± 6.1 ms versus narrow QRS: 25.9± 15.3 ms versus wide QRS: 28.6±14.4ms, both P < 0.05 versus controls) was prolonged in both the narrow and wide QRS groups compared with normal controls. Similarly, the maximal difference in time to peak diastolic velocity (controls: 39± 16.8 ms versus narrow QRS: 73.1± 58ms versus wide QRS: 108.5± 168 ms, both P < 0.05 versus controls) and in standard deviation of time to peak early diastolic velocity of 12 LV segments (controls: 15.3±5.8ms versus narrow QRS: 25.1± .13.8ms versus wide QRS: 25.5± 14.9ms, both P < 0.05 versus controls) was prolonged in both the narrow and wide QRS groups. The respective prevalence of systolic and diastolic asynchrony was 31.4% and 20%, in the narrow QRS group, and 40% and 28.6%, in the wide QRS group respectively. Stepwise multiple regression analysis showed that low ejection fraction and low mitral annular early diastolic velocity were independent predictors of both systolic and diastolic asynchrony. QRS complex duration was found to correlate only with diastolic asynchrony. Conclusion: LV systolic and diastolic mechanical asynchrony is common in patients with HF regardless of QRS duration. Selection for cardiac resynchronization treatment should also be based on information about systolic and diastolic synchronicity.