Thus, all Kcne2‐/‐ mice (15 out of 15, P = 0.0006 vs. Kcne2+/+ mice) developed arrhythmias throughout reperfusion including ventricular tachycardia (VT), atrioventricular block (AVB), polymorphic ventricular tachycardia (PVT), or sustained ventricular tachycardia (SVT) exceeding 10 sec duration. The gene discussed is KCNE2; the disease is atrioventricular block.