GJA1 and cardiac arrhythmia: The distribution of CX43 also changed from the end-to-end junction located at the leap disc to the side-to-side junction parallel to the long axis of cardiac fibers, and the arrangement of CX43 was disordered or even disappeared, resulting in abnormal conduction of impulses and changes in synchronization and coordination of cardiac electrical activity, eventually resulting in arrhythmia.