Several studies have shown that, before the onset of AF, shorter atrial ERPs and a longer IACT are associated with higher inducibility of AF in HF patients and animals.37, 38, 39 Moreover, earlier work from our group showed that MD1 deletion can increase the AF induction rate in the setting of HFD.18 Therefore, a deficiency in MD1 can increase vulnerability to AF caused by aldosterone‐induced HFpEF. This evidence concerns the gene LY86 and hydrops fetalis.