In patients with dilated cardiomyopathy, a QRS duration ≥120 ms was associated with a loss of correlation between global wasted work and global longitudinal strain (r=-0.022, p=0.9483).
Observational (n=29)
Does QRS duration modify the relationship between myocardial work indices and global longitudinal strain in patients with dilated cardiomyopathy?
In patients with dilated cardiomyopathy, a prolonged QRS duration (≥120 ms) disrupts the correlation between global wasted work and both global longitudinal strain and global work index, indicating that electrical dyssynchrony leads to uncoupled mechanical inefficiency.
Abstract Background Myocardial work (MW) has emerged as an innovative echocardiographic parameter for the comprehensive evaluation of myocardial performance, with utility in the clinical assessment of patients with dilated cardiomyopathy (DCM). However, the influence of electrical conduction delays on the relationship between myocardial work and deformation has not been fully elucidated. Objective To assess whether QRS duration modifies the relationship between myocardial work indices and global longitudinal strain (GLS) in patients with DCM. Methods 29 patients with non-ischemic DCM underwent echocardiographic assessment of GLS and myocardial work indices-including global constructive work (GCW), global wasted work (GWW), global work index (GWI), global work efficiency (GWE)-as well as a 12-lead ECG. Patients were stratified into two groups based on QRS duration: 120 ms and ≥120 ms. Correlations between myocardial work indices and GLS were analysed within each group. Results 29 patients meeting echocardiographic criteria for DCM - characterized by left ventricular enlargement (mean indexed end-diastolic volume EDVi 102ml; mean indexed end-systolic volume ESVi 71ml), accompanied by reduced systolic function (mean ejection fraction EF 28.1 +/- 10.6), in the absence of underlying coronary artery disease - were included. The mean age was 57.8 +/- 15.3 years. Patients were further classified into two groups based on QRS duration; 41.4% had a QRS duration ≥120 ms. Compared to those with a QRS 120ms, patients with a prolonged QRS showed significaly lower GCW, GWI, GWE and GLS, while no significant difference was observed in GWW. In the narrow QRS group, both GLS and GWI were strongly and inversely correlated with GWW (r=-0.652, p=0.0046 and r=-0.698, p=0.0018, respectively). However, these correlations were not significant in the wide QRS group GLS and GWW: r=-0.022, p=0.9483; GWI and GWW: r=0.222, p=0.4875. Conclusion In the patients with DCM and narrow QRS, GWW correlated strongly with both GLS and GWI, indicating synchronised deterioration of function and efficiency. However, in those with QRS ≥120 ms, these correlations were lost, suggesting that electrical dyssynchrony leads to disorganized and uncoupled mechanical inefficiency. This highlights a novel mechanistic link between QRS duration and the interpretability of myocardial work metrics in DCM.MW indices stratified by QRS duration QRS based MW-GLS correlations
Hart-Foia et al. (2026) conducted an observational in Dilated cardiomyopathy (DCM) (n=29). Prolonged QRS duration (≥120 ms) vs. Narrow QRS duration (<120 ms) was evaluated on Correlation between global wasted work (GWW) and global longitudinal strain (GLS). In patients with dilated cardiomyopathy, a QRS duration ≥120 ms was associated with a loss of correlation between global wasted work and global longitudinal strain (r=-0.022, p=0.9483).