High prevalence of left ventricular systolic and diastolic asynchrony in patients with congestive heart failure and normal QRS duration

Abstract

Objective: To study the possible occurrence of left ventricular (LV) systolic and diastolic asynchrony in patients with systolic heart failure (HF) and narrow QRS complexes.

Design: Prospective study.

Setting: University teaching hospital.

Patients: 200 subjects were studied by echocardiography. 67 patients had HF and narrow QRS complexes (< or = 120 ms), 45 patients had HF and wide QRS complexes (> 120 ms), and 88 served as normal controls.

Interventions: Echocardiography with tissue Doppler imaging was performed using a six basal, six mid-segmental model.

Main outcome measures: Severity and prevalence of systolic and diastolic asynchrony, as assessed by the maximal difference in time to peak myocardial systolic contraction (T(S)) and early diastolic relaxation (T(E)), and the standard deviation of T(S) (T(S)-SD) and of T(E) (T(E)-SD) of the 12 LV segments.

Results: The mean (SD) maximal difference in T(S) (controls 53 (23) ms v narrow QRS 107 (54) ms v wide QRS 130 (51) ms, both p < 0.001 v controls) and in T(S)-SD (controls 17.0 (7.8) ms v narrow QRS 33.8 (16.9) ms v wide QRS 42.0 (16.5) ms, both p < 0.001 v controls) was prolonged in the narrow QRS group compared with normal controls. Similarly, the maximal difference in T(E) (controls 59 (19) ms v narrow QRS 104 (71) ms v wide QRS 148 (87) ms, both p < 0.001 v controls) and in T(E)-SD (controls 18.5 (5.8) ms v narrow QRS 33.3 (27.7) ms v wide QRS 48.6 (30.2) ms, both p < 0.001 v controls) was prolonged in the narrow QRS group. The prevalence of systolic and diastolic asynchrony was 51% and 46%, respectively, in the narrow QRS group, and 73% and 69%, respectively, in the wide QRS group. Stepwise multiple regression analysis showed that a low mean myocardial systolic velocity from the six basal LV segments and a large LV end systolic diameter were independent predictors of systolic asynchrony, while a low mean myocardial early diastolic velocity and QRS complex duration were independent predictors of diastolic asynchrony.

Conclusions: LV systolic and diastolic mechanical asynchrony is common in patients with HF with narrow QRS complexes. As QRS complex duration is not a determinant of systolic asynchrony, it implies that assessment of intraventricular synchronicity is probably more important than QRS duration in considering cardiac resynchronisation treatment.

Figure 1

Scatterplot showing (A) the distribution of the standard deviation of the time to peak myocardial sustained systolic velocity (T_S-SD) and (B) early diastolic velocity (T_E-SD) of all 12 left ventricular segments in normal controls, in patients with heart failure and narrow QRS complexes, and in patients with heart failure and wide QRS complexes. *p < 0.001 v controls; †p = 0.009 v normal QRS group; ‡p = 0.002 v normal QRS group.

Figure 2

Regional myocardial velocity curves obtained by tissue Doppler imaging at the basal septal (yellow) and basal lateral (green) segments. In the left hand panels the systolic movement of the myocardium is encoded by colour Doppler with movement towards the probe shown in red and that away from the probe in blue. (A) In the normal control, there is simultaneous peaking of systolic contraction (S_M) and early diastolic relaxation (E_M) in the basal septal and basal lateral segments in the apical four chamber view. Tissue colour tracking shows systolic contraction in red in both regions. (B) In patients with heart failure and normal QRS duration, there is a dramatic reduction in the amplitude of peak S_M and peak E_M in both regions. In addition, there is delay in reaching peak S_M in the basal lateral segment E_M of 120 ms. A difference in peak early diastolic relaxation of 60 ms is also seen. Tissue tracking in early systole shows a delayed systolic movement in the basal and mid-lateral segments, shown in blue (arrow heads).