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Abstract

Why the heart is like an orchestra and the uterus is like a soccer crowd TO THE EDITORS: Thank you for your interesting commentary on the mechanism of uterine activity leading to organized labor. 1 Your analogy of the soccer stadium (or perhaps football in an American context) for uterine contractility in labor as compared with the organized sequence of cardiac contractility is very apt. It is almost certainly true that organized uterine contractions (labor) are possible only because of the ability of electrical activity to propagate through gap junctions. Drs Mel Barclay, Carl Simon, and I investigated a computer model of uterine activity based on the concept of propagation via gap junctions. 2 The model demonstrated organized propagation of contractile activity when adequate connections were available between the cells of the computer model. 3 Dr Barclay and I had many conversations about the presence or absence of a pace-making function in the uterus. He believed that the anatomic studies of Toth and Toth 4 demonstrated a pacemaker region, whereas I am skeptical. The computer model, 5 admittedly simple, that we developed required a pacemaker function for prolonged contractile activity; however, we found some evidence that more accurate modeling of electrical characteristics of the cells would generate self-sustaining patterns. I suspect that regions of the myometrium with higher rates of contractility eventually take over the coordination of contraction patterns. Unfortunately, our studies did not continue after Dr Barclay's death in 2010. I continue to believe that further modeling of the uterus as a construction of cellular automata with connections governed by physiological and electrochemical processes that you summarize will advance our understanding of both organized and disorganized (dysfunctional) labor.