Objectives

To investigate myocardial contractility in patients with severe excessive trabeculation but normal left ventricular ejection fraction (LVEF) through feature tracking strain analysis, and the correlation between the extent of excessive trabeculation assessed by fractal dimension (FD) and myocardial contractility in patients with left ventricular noncompaction (LVNC) and normal LVEF.

Methods

Forty-one LVNC patients with normal LVEF (≥50%) and 41 healthy controls were retrospectively included. All patients fulfilled three available diagnostic criteria on MRI: 1) the presence of noncompacted and compacted LV myocardium with a two-layered appearance, with at least involvement of the LV apex; 2) end-diastolic NC/C ratio >2.3 on long-axis views and ≥3 on short-axis views; 3) noncompacted mass >20% of the global LV mass. No pathologic (pressure/volume load, e.g., hypertension) or physiologic (e.g., pregnancy and vigorous physical activity) remodelling factors leading to excessive trabeculation existed. Cardiac MRI feature tracking was performed on cine images to determine left ventricular (LV) peak strains in three directions: global radial strain (GRS), global circumferential strain (GCS) and global longitudinal strain (GLS). The complexity of excessive trabeculation was quantified by fractal analysis on short-axis cine stacks.

Results

Compared with controls, patients with LVNC had impaired GRS, GCS and GLS (GRS, 31.06% [27.36%, 33.84%] versus 35.92% [31.27%, 41.21%]; GCS, -18.11 ± 2.67% versus -20.24 ± 2.16%; GLS, -15.20 ± 2.25% versus -16.28 ± 2.36%; all p<0.05). The global, maximal and regional FD values of the LVNC population were all significantly higher than those of the controls (Figure 1, all p<0.05). Global FD was positively correlated with the end-diastolic volume index, end-systolic volume index and stroke volume index (r =0.483, 0.505 and 0.335, respectively, all p<0.05), but negatively correlated with GRS and GCS (r= -0.458 and 0.508, respectively, both p<0.001). Moreover, apical FD was also weakly associated with LVEF and GLS (r=-0.249 and 0.252 respectively, both p<0.05).

Conclusion

In patients with LVNC, LV systolic dysfunction was detected early by cardiac MRI feature tracking despite the presence of normal LVEF and was associated with excessive trabecular complexity assessed by FD.

Acknowledgements

No acknowledgement found.

References

No reference found.