RYR2 and atrial standstill: However, carriers of exon3 deletions of RYR2 have been reported to show a distinct phenotype of CPVT characterized by concomitant SND, AVB, atrial fibrillation, atrial standstill, dilated cardiomyopathy, and LVNC/hypertrabeculation.(Bhuiyan et al., 2007; Marjamaa et al., 2009; Medeiros‐Domingo et al., 2009; Ohno et al., 2014; Szentpali et al., 2013).