Lactate sensitivity and cardiac cholinergic function in panic disorder.

Using spectral analysis of the continuous time series signal before and during lactate and placebo infusions, the authors studied heart rate variability in six patients with panic disorder and nine normal comparison subjects. The decrease in high-frequency (0.20-0.50 Hz) power and the increase in sympathovagal ratios (mid-frequency [0.07-0.15 Hz] to high-frequency powers) after the administration of intravenous sodium lactate were significantly greater in the patients than in the normal subjects after correction of the values for the amount of lactate infused. This result suggests an exaggerated cardiac vagal withdrawal in patients with panic disorder during lactate infusions.