It is intriguing that in the absence of an underlying disease process, such as tachycardia-induced cardiomyopathy, hypertrophy or ischemia, short-term pacing of the heart at rates just above that of normal sinus rhythm should produce significantly decreased Cx43 mRNA levels and intracellular redistribution of Cx43 protein. The gene discussed is GJA1; the disease is cardiomyopathy.