Cardiovascular magnetic resonance findings in a pediatric population with isolated left ventricular non-compaction

Abstract

Background: Isolated left ventricular non-compaction (LVNC) is an uncommon disorder characterized by the presence of increased trabeculations and deep intertrabecular recesses. In adults, it has been found that ejection fraction (EF) decreases significantly as non-compaction severity increases. In children however, there are a few data describing the relation between anatomical characteristics of LVNC and ventricular function. We aimed to find correlations between morphological features and ventricular performance in children and young adolescents with LVNC using cardiovascular magnetic resonance (CMR).

Methods: 15 children with LVNC (10 males, mean age 9.7 y.o., range 0.6-17 y.o.), underwent a CMR scan. Different morphological measures such as the compacted myocardial mass (CMM), non-compaction (NC) to the compaction (C) distance ratio, compacted myocardial area (CMA) and non-compacted myocardial area (NCMA), distribution of NC, and the assessment of ventricular wall motion abnormalities were performed to investigate correlations with ventricular performance. EF was considered normal over 53%.

Results: The distribution of non-compaction in children was similar to published adult data with a predilection for apical, mid-inferior and mid-lateral segments. Five patients had systolic dysfunction with decreased EF. The number of affected segments was the strongest predictor of systolic dysfunction, all five patients had greater than 9 affected segments. Basal segments were less commonly affected but they were affected only in these five severe cases.

Conclusion: The segmental pattern of involvement of non-compaction in children is similar to that seen in adults. Systolic dysfunction in children is closely related to the number of affected segments.

Figure 1

Linear regression and correlations between EF and different morphological measurements. There was a low correlation between all these parameters and EF. None of these measurements are a good indicator of ventricular performance in children with isolated LVNC. (Compacted mass is in g/m² and measures of areas are in cm²/m²).

Figure 2

Linear regression and correlations. Linear regression and correlations between myocardial compacted mass, non compacted area, and compacted area with ESV and EDV were higher than those found in for EF (Figure 1). However, linear regression plots were also scattered indicating a poor linear relationship between these morphological indexes and ESV or EDV. (LV-ESV and LV-EDV are in cc/m², compacted mass in g/m² and measures of area are in cm²/m²).

Figure 3

Distribution of segments with LVNC in all patients. Those patients with more than 9 affected segments were the only ones with compromise of left ventricular performance. Basal segment involvement tended to occur in more severe cases.

Figure 4

A five years old female with EF 41.5%. Steady-state free precession magnetic resonance imaging in a Long Axis (a), four-chamber (b) and short-axis (c, d, e) views demonstrate extensive trabeculations of the LV wall in the basal (e), mid (d) and apical segments (c).

Figure 5

Result of the 17-segment analysis of wall motion abnormality and non compation (numbers indicate degree of wall motion abnormalities according to text). These patient were the only ones who had wall motion abnormalities and and Ejection Fraction (EF) < 53%. Interestingly, in the more severe cases there were wall motion abnormalities in septal segments non-affected by no compaction.