Background: Post-mortem studies in patients with achalasia reveal degenerative changes in the vagus and its dorsal motor nuclei suggesting the possibility of widespread autonomic dysfunction.
Aims: To study a broad range of autonomic function in patients with achalasia and nutcracker oesophagus and in asymptomatic volunteers.
Subjects: Patients with a manometric diagnosis of achalasia and nutcracker oesophagus and age- and sex-matched asymptomatic volunteers.
Methods: Subjects underwent measurement of: (1) pupil cycle time estimation; (2) heart rate response to the Valsalva manoeuvre, standing and deep breathing; (3) systolic blood pressure response to standing; (4) diastolic response to sustained handgrip; (5) spectral analysis of heart rate variability; and (6) heart rate and blood pressure during the Valsalva manoeuvre.
Results: No significant differences were found between patients with achalasia and asymptomatic volunteers. Patients with nutcracker oesophagus, however, had longer pupil cycle times (1.2 (0.9-1.4) s versus 0.9 (0.8-1.2) s, P= 0.02) and had attenuation of both the rise in the low frequency peak of heart rate variability and the fall in the high frequency peak on standing (rise in low frequency peak - patients 26.6 (10.4-52.3)% to 42.2 (15.5-54.0)%, P = 0.46, volunteers 16.9 (8.4-37.2)% to 47.4 (21.1-66.3)%, P = 0.03; fall in high frequency peak - patients 18.1 (0.9-43.3)% to 10.1 (0.5-26.6)%, P= 0.46, volunteers 24.8 (8.5-44.4)% to 9.3 (2.6-35.6)%, P= 0.03). The rise in blood pressure during the Valsalva manoeuvre was also attenuated in patients with nutcracker oesophagus compared with asymptomatic volunteers (6.9 (1.0-9.3) mmHg versus 12.9 (11 -23.0) mmHg, P < 0.01).
Conclusions: Whereas tests of cardiovascular and pupillary autonomic function are normal in patients with achalasia, patients with nutcracker oesophagus show defects in both parasympathetic and sympathetic function.