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. Author manuscript; available in PMC: 2015 Oct 1.
Published in final edited form as: Gastrointest Endosc Clin N Am. 2014 Aug 1;24(4):545–561. doi: 10.1016/j.giec.2014.07.001

Figure 4.

Figure 4

Premature contraction is defined as a distal latency (DL) <4.5 s (Panels A and B); in conjunction with normal EGJ relaxation they are the defining features of distal esophageal spasm. The contractile front velocity (CFV) of a premature contraction might be elevated (>9 cm/s) (Panel A) or normal (Panel B). The clinical significance of rapid contraction with normal DL (Panel C) remains to be determined. A weak contraction (DCI <450 mmHg-s-cm) with a reduced distal latency is considered failed (Panel D).