The electrocardiogram showed no obvious abnormalities in the waveforms of Vasn+/+ and Vasn+/− mice (Figure 1A1), but the Vasn−/− mice showed common PCH waveforms such as atrioventricular block, left atrial hypertrophy, ST segment depression, T‐wave inversion, and ST‐T changes (Figure 1A2). This evidence concerns the gene VASN and atrioventricular block.