Although hiccups may increase vagal discharges by modulating changes in respiratory stretch receptors or atrial filling, it is more likely that a hiccup-induced Valsalva maneuver was responsible for abolishing ventricular bigeminy in our patient. This would explain the delay that was shown on the ECG between the occurrence of the hiccup artifacts and the termination of the extrasystoles. The patient's critical condition prevented our determining the effect of altering parasympathetic activity, but our observations led us to believe that the relationship between the occurrence of hiccups and the disappearance of ventricular extrasystoles was more than coincidental.