Presence Of Left Ventricular Non Compaction In Hypertrophic Cardiomyopathy Is Associated With Arrhythmia

Background

Cardiac magnetic resonance (CMR) imaging allows accurate assessment of ventricular compaction. We aimed to determine whether left ventricular non-compaction (LVNC) is related to increased incidence of arrhythmia in adults with Hypertrophic cardiomyopathy (HCM).

Methods

58 consecutive HCM patients referred for CMR between 2008-2014 were recruited. Only patients with intermediate ventricular thickness of 15-29 mm were included. Patients with apical HCM, severe LV outflow tract obstruction (resting gradient >50 mmHg) and significant loading conditions, such as aortic stenosis or hypertension, were excluded. LVNC was diagnosed as per Petersen's criteria.

Results

66% of the patients were male, mean age 52 ± 18 years, mean wall thickness was 19 ± 4 mm. Amongst the 9 patients with LVNC, 5 had VT/VF, 2 had SVT and 2 had syncope. Patients with LVNC had a significantly higher prevalence of ventricular arrhythmia than those without LVNC (56% vs 18%, p = 0.03), with a relative risk of 3.0 (95% CI 1.3 - 6.9). LV septal thickness (18.4 ± 5.6 mm vs 18.7 ± 3.5 mm, p = 0.9) and ejection fraction (70 ± 7.7 vs 70 ± 10.5%, p = 0.9) did not significantly differ between those with LVNC and those without. Presence of LV scar assessed by late gadolinium enhancement was similar between the groups (89% vs 73%, p = 0.7).

Conclusions

Presence of LVNC may be associated with ventricular tachyarrhythmia in HCM patients and may provide a new phenotypic marker for adverse prognosis, especially in the intermediate risk group. Further studies in larger populations are required to assess its possible prognostic value.