European Journal of Cardio-Thoracic Surgery, Vol 12, 75-81, Copyright © 1997 by European Association for Cardio-thoracic Surgery
Temporary loss of cardiac autonomic innervation after the maze procedure
PR Vogt, HP Brunner La Rocca, R Candinas, J Gasser, G Zund, M Schonbeck, M Genoni and MI Turina
Division of Cardiovascular Surgery, University Hospital, Zurich, Switzerland.
OBJECTIVE: Blunted sinus node response to exercise has been reported after
the maze operation. We suggested the autonomic vegetative function of the
heart to be disturbed after the maze procedure. METHODS: 17 patients, mean
age 63 +/- 15 years, with chronic atrial fibrillation for 49 +/- 46 months
(range 5-65) underwent the maze procedure during mitral valve surgery.
Bicycle stress test, 24-h electrocardiography and heart rate variability
were analysed in 11 patients after three and in six after 14 +/- 3 months.
Spectral analysis within two frequency bands, vector analysis of the main
circular resultant and influence of orthostasis and Valsalva manoeuvre on
different R-R intervals were calculated. RESULTS: One patient died from a
perioperative ischaemic stroke. At follow-up, all patients were in sinus
rhythm. Heart rate reached 84 +/- 14%, the mean circular resultant was 60
+/- 48%, the ratio of the longest to the shortest R-R interval during the
Valsalva manoeuvre was 92 +/- 8% and the ratio of maximal to minimal R-R
interval after orthostasis was 98 +/- 4% of the age-adjusted normal value.
Maximal workload was 116 +/- 31 watts. All patients had abnormal heart rate
variability. Heart rate variability was significantly more blunted after
three months, than after 14 months (P < 0.05). The minimal heart rate
and the difference between the maximal and the minimal heart rate during
the 24-h electrocardiography were significantly correlated to the number of
normal physiological tests (r = -0.52; P < 0.05; r = 0.71; P <
0.005); for the maximal heart rate, there was a positive trend only (r =
0.44; P = 0.07). CONCLUSIONS: Early after the maze procedure, a nearly
total denervation of the sinus node is present, similar as seen after heart
transplantation, with partial restoration of the autonomic function after
one year. The exercise capacity of the patients was satisfactory.