Three-dimensional echocardiographic characterization of patients with left ventricular noncompaction

Despite several efforts using two-dimensional echocardiography and cardiac magnetic resonance in the diagnosis of left ventricular noncompaction (LVNC), there are no universally accepted diagnostic criteria. The aim of this study was to describe the extent of noncompacted myocardium using a new three-dimensional echocardiographic parameter.

Seventeen patients with diagnoses of LVNC on the basis of two-dimensional echocardiographic and clinical criteria, 26 Olympic rowing athletes, and 49 healthy volunteers underwent three-dimensional echocardiography. By offline analysis, left ventricular volumes, mass, ejection fraction, and sphericity index were calculated. Trabeculated left ventricular volume (TLV) was calculated as the difference between left ventricular end-diastolic volume obtained including and excluding the trabeculae in the cavity contour. TLV was also normalized by left ventricular end-diastolic volume (TLV%).

TLV and TLV% were significantly higher in patients with LVNC (33.7 ± 10.9 mL and 24 ± 7%) as opposed to controls (7.1 ± 2.2 mL, P < .001, and 6 ± 2%, P < .001, respectively) and athletes (8.0 ± 3.0 mL, P < .001, and 5 ± 2%, P < .001, respectively). In detail, on receiver operating characteristic curve analysis, optimal cutoff values of 15.8 mL for TLV and 12.8% for TLV% were determined for the identification of LVNC (area under the curve, 1.00; P < .001). Mild positive correlations of TLV and TLV% were found with sphericity index (r = 0.294, P = .004, and r = 0.301, P = .004, respectively), and mild negative correlations were found with ejection fraction (r = -0.454, P < .001, and r = -0.217, P = .038, respectively).

Because of high spatial resolution and accuracy in volumetric quantification, three-dimensional echocardiography allows accurate measurement of the extent of noncompacted myocardium and identification of patients with LVNC.