Patients with a DPP6 risk- haplotype for familial idiopathic ventricular fibrillation have normal left systolic function but abnormal deformation

Abstract

Type of funding sources: None. An aberrant DPP6 mutation haplotype on chromosome 7 is associated with familial idiopathic ventricular fibrillation in severely affected Dutch families with numerous cases of  sudden cardiac death (SCD) So far, no clinical parameters could be linked to predict SCD risk other than this genetic predisposition. In various other cardiac disease, global longitudinal strain (GLS) and mechanical dispersion (MD), both markers of left ventricular (LV) dysfunction, are predictive tools for patients at risk for ventricular arrhythmias (VA) and SCD. The goal of the current study was to investigate whether LV dysfunction, detected by GLS and MD, is present in patients with DPP6 haplotype. DPP6 risk-haplotype carriers with sufficient echocardiographic images were included as cases (n = 31, 15 males mean age 41 ± 11 years) and individuals evaluated during cascade screening who were tested but appeared not to be affected as controls (n = 14, 7 males, mean  age 39 ± 12 years). Echocardiographic bi-plane ejection fraction (LVEF), GLS and MD of the left ventricular were determined. LVEF was similar between DPP6 cases (57.3%) and controls (60.5%, p = 0.07). In contrast, the GLS of the LV (-18.0%) of DPP6 cases was significant lower compared to controls (-21.1%, p < 0.0001). MD in DPP6 cases (43.4ms) was significantly higher than in controls (26.7ms, p < 0.0001). DPP6 risk- haplotype carriers have similar LVEF, but significant lower LV-GLS and higher mechanical dispersion than controls. These findings can be used for clinical discrimination. Whether these markers can be used for prediction of clinical events has to be determined after a longer follow up. echocardiographic characteristics controls DPP6 p-value LVEF (%) 60.5 57.3 0.07 GLS LV (%) -21.2 -18.0 0.0001 MD ( ms) 26.7 43.4 0.0001