Abstract 3209: Cardiac Magnetic Resonance in Lamin A/C Cardiac Conduction and Myocardial Disease: Pattern of Fibrosis and Clinical Correlates
Background. Various forms of nonischemic cardiomyopathy result in distinct myocardial enhancement patterns on late post-gadolinium cardiac magnetic resonance imaging (LGE-CMR); the findings in lamin a/c cardiac conduction and myocardial disease (LCCMD) have not been described.
Methods and Results. Ten living genotype-positive family members without contraindication to magnetic resonance and sharing an identical frameshift mutation in LMNA were identified from a 150-member pedigree. 8 autopsy hearts from deceased relatives were reviewed in sections comparable to LGE imaging. Each patient underwent clinical, electrocardiographic, and CMR assessment. LGE was positive in 3 subjects, notably the 3 oldest patients in the cohort (age 45±7 years compared to 26±10 years for LGE-negative subjects, p = 0.02). The pattern of fibrosis, midmyocardial enhancement of the basal interventricular septum was identical to that seen in 6 autopsy specimens of related genotype-positive family members (Figure⇓). Systolic function was normal in all subjects. Diastolic function by mitral inflow velocities was abnormal in LGE-positive subjects and normal in LGE-negative subjects.
Conclusion. LGE-CMR can identify distinctive patterns of fibrosis under genetic control in vivo in patients with LCCMD that is similar in distribution to that observed by examination of the explanted heart. Myocardial fibrosis may form the substrate for diastolic dysfunction in these patients.