Analysis of left ventricular systolic function in patients with isolated ventricular noncompaction by cardiac MRI

Abstract

Objective To compare cardiac magnetic resonance imaging (MRI) features between patients with normal and decreased left ventricular (LV) systolic function in isolated ventricular noncompaction (IVNC) and to analyze the related factors of LV systolic function. Methods In a retrospective blinded study, 62 IVNC patients were divided into two subgroups: those with normal LV systolic function [LV ejection fraction (LVEF) ≥55%) ] and those with decreased LV systolic function (LVEF< 55%). A total of 30 healthy volunteers were enrolled as controls. The LVEF, LV volume, number of non-compacted segments, ratio of non-compacted to compacted myocardium (NC/C ratio) , and delayed enhancement were assessed using cardiac MRI. One-way analysis of variance, independent t test and χ2 test were used. The correlation between LVEF and the number of non-compacted segments or NC/C ratio were calculated with Spearman and Pearson correlation analysis. Results The LVEF of patients with normal LVEF [ (58.8±3.8) %] and patients with decreased LVEF [ (31.1±11.1) %] were less than that of control group [ (66.1±6.0) %], which demonstrated significant differences (F=140.789, P 0.05). The patients with decreased LVEF had significantly greater LV volume compared with patients with normal LVEF and control group (P<0.05). The number of non-compacted segments in patients with decreased LVEF (7.5±1.0) was more than that of the patients with normal LVEF (5.6± 1.0) , and the NC/C ratio in patients with decreased LVEF (4.4±0.9) was higher than that of patients with normal LVEF (3.4±0.7) , which demonstrated significant differences (t=7.248, 4.472, P<0.01). There was significant difference in the rate of delayed enhancement between patients with decreased LVEF (18/42) and patients with normal LVEF (1/20) (χ2=9.136, P<0.01). The non-compacted segments were more common in apex, apical and mid lateral segments in two IVNC groups, and there were no involvement of basal septal, mid septal and mid inferior segments. Some basal segments were involved in patients with decreased LVEF, while there were no basal segments involved in patients with normal LVEF. The number of non-compacted segments and NC/C ratio were correlated negatively with LVEF (r=- 0.690, - 0.591, respectively,P<0.01). Conclusions The dilation, remodeling and myocardial delayed enhancement of LV in IVNC patients can lead to decreased LV systolic function. In addition, the extent and severity of non-compacted myocardium in IVNC patients are correlated negatively with LVEF. Key words: Cardiomypathies; Ventricular dysfunction, left; Magnetic resonance imaging