Table 1.

Esophageal contractile patterns, their defining characteristics, and their codes after analysis of the ten component test swallows for input to the CART model. These differ from the final Chicago Classification diagnoses in that in some cases they could be modified to an achalasia subtype or EGJ outflow obstruction depending on the corresponding IRP value. For instance, absent peristalsis could be modified to type I achalasia.

Contractile pattern	Code	Definition
Absent Peristalsis	AP	100% failed peristalsis with minimal (<3 cm) integrity of the 20 mmHg IBC† distal to the proximal pressure trough (P)
Frequent Failed Peristalsis	FFP	Greater than 3 but less than 10 swallows with failed peristalsis
Panesophageal Pressurization	PP	≥20% of swallows with uniform pressurization of 30 mmHg from the UES to the EGJ
Premature Contraction	PC	≥20% of swallows with DL ≤4.5 s
Jackhammer	JH	Swallow with DL >4.5 s and DCI >8000 mmHg-s-cm
Rapid Contraction	RC	≥20% of swallows with contractile front velocity (CFV) >9 cm/s and DL > 4.5 seconds
Hypertensive	HT	Mean DCI greater than 5000 but no swallow with value >8,000 mmHg-s-cm
Weak Peristalsis	WP	> 20% swallows with large breaks in the 20 mmHg IBC (>5 cm in length) or >30% swallows with small breaks in the 20 mmHg IBC (2–5 cm in length)
Normal Peristalsis	NP	≥60% of swallows with an intact 20 mmHg IBC (or no break >2 cm) not meeting any other code

^†IBC = Isobaric contour