Possible vagal effect of lidocaine: investigation by HR spectral analysis

Spectral analysis of heart rate (HR) fluctuations was applied to investigate the effect of lidocaine on autonomic control of human sinus rate both in normal volunteers and in patients in the acute phase of myocardial infarction. Integrating the HR power spectrum over a predetermined frequency band, the authors focused mainly on the respiratory frequency band, known to predominantly reflect parasympathetic control. The administration of lidocaine resulted in an overall increase in mean HR. The findings consistently indicate that lidocaine has a significant parasympatholytic effect on the human heart, in healthy volunteers as well as in patients in the acute phase of myocardial infarction