Clinical significance of right ventricular dysfunction in left ventricular non-compaction cardiomyopathy

Left ventricular non-compaction (LVNC) is described as the persistence of trabeculated myocardium in the left ventricle (LV) and is optimally assessed by cardiac magnetic resonance (CMR). Right ventricular (RV) involvement in LVNC remains poorly studied. Consecutive patients (N = 14) diagnosed with LVNC by CMR were studied. Their clinical data were analyzed. In addition, CMR assessment included quantification of LV and RV volumes, mass, ejection fraction (EF), LV wall motion score, LV non-compacted segments and noncompacted to compacted myocardium ratios. Average age of presentation was 33.1 ± 17.6 years old, with 9 males (64%). Of these patients, 7 (50%) presented with acute heart failure and 3 (21%) with syncope, including 1 documented ventricular tachycardia. RV EF <35% was identified in 7 (50%) of these patients. Patients with RV EF <35% presented at a higher median New York Heart Association class (1 [IQR 1-2] vs. 3 [IQR 2-4], P = 0.021) and had significantly lower LV EF (50.7% ± 15.4 vs. 21.8% ± 19.9, P = 0.029), higher LV end diastolic (100.9 ml/m² ± 22.3 vs. 159.1 ml/m² ± 36.0, P = 0.002) and systolic volume indices (52.0 ml/m² ± 25.8 vs. 129.1 ml/m² ± 48.4, P = 0.002), higher LV wall motion score index (1.3 ± 0.5 vs. 2.2 ± 0.6, P = 0.004) and higher ratio of LV non-compacted to compacted myocardium (3.3 ± 0.6 vs. 4.1 ± 0.8, P = 0.026). All 4 patients that had ventricular tachycardia also had RV dysfunction. RV dysfunction was present in half of patients with LVNC. Significant RV dysfunction seems to be a marker of advanced LVNC and may carry a worse prognosis. Further studies in a larger sample of patients are needed to confirm those observations.