Is there a relationship between the helical pattern of hypertrophy and atrial fibrillation in patients with hypertrophic cardiomyopathy?

Purpose: Atrial fibrillation (AF) is commonly seen in patients with hypertrophic cardiomyopathy (HCM) and is associated with left atrial enlargement, fibrosis and diastolic dysfunction. Cardiac magnetic resonance (CMR) imaging provides important information about the geometric pattern of hypertrophy that may related to worse clinical outcomes such as arrhythmic events. The purpose of this study was to determine whether helical pattern is associated with increased risk for AF and diastolic dysfunction in patients with HCM. Methods: : A total of 50 consecutive patients with HCM referred for CMR imaging were enrolled into the study. The helical pattern was evaluated by measurement of the maximal left ventricle wall thickness (LVWT) for each of the 17 classical LV segments. Results: : A spiral pattern was observed in 20 patients (40%). We found significantly higher incidence of AF in patients who detected helical distribution than in those who did not (40% vs. 10%, p = 0.012). Left atrial volume index (LAVI) was also higher in patients with helical pattern compared to non-helical pattern (32.5 mL/m2 ± 16.9 vs. 23.7 mL/m2 ± 5.8; p < 0.001). Conclusion: Our study suggests that presence of helical pattern is associated with significantly increased risk of development AF and LAVI in HCM patients.