Hypercontractile esophagus (nicknamed jackhammer esophagus) is a recently 
defined disease within the esophageal motility disorders classification. 
Responses to treatments for jackhammer esophagus have been inconsistent in 
previous trials, possibly due to its heterogeneous manifestation. Thus, we 
reviewed 10 patients diagnosed with jackhammer esophagus and compared their 
clinical and manometric features at baseline. Additionally, manometric and 
symptomatic responses after treatment with known smooth muscle relaxants, 
including anticholinergic drugs (cimetropium bromide and scopolamine 
butylbromide) and a phosphodiesterase-5 inhibitor (sildenafil) were compared. We 
observed two distinct subgroups in the findings: one with hypercontractility and 
normal distal latencies ("classic jackhammer esophagus," n=7) and the other with 
hypercontractility and short distal latencies ("spastic jackhammer esophagus," 
n=3). The two types also differed in their responses to medications in that 
symptoms improved upon treatment with an anticholinergic agent in classic 
jackhammer esophagus patients, while spastic jackhammer esophagus was 
unresponsive to both the anticholinergic drugs and the phosphodiesterase-5 
inhibitor. In conclusion, hypercontractile esophagus may be a heterogeneous 
disease with different underlying pathophysiologies. We introduced two novel 
terms, "classic jackhammer esophagus" and "spastic jackhammer esophagus," to 
distinguish the two types.