Transdermal scopolamine increases heart rate variability by selective parasympathetic stimulation

Summary form only given. It was hypothesized that the transdermal application of low-dose scopolamine using the unique therapeutic system Transderm Scop would selectively augment parasympathetic cardiac reflex activity and increase heart rate variability. The authors tested several indices of heart rate variability in 31 healthy adults (age: 31+or-7 years) after 234 hours of exposure to one patch of transdermal scopolamine. It was confirmed that transdermal scopolamine markedly increases heart rate variability in healthy human adults. Power spectrum analysis of R-R intervals appears to be a very sensitive measure of changes occurring within the autonomic nervous system. Changes in the power of the 0.25-Hz band, in particular, reliably indicate changes in parasympathetic nervous system activity. Transdermal scopolamine thus holds promise as a therapeutic intervention for selectively enhancing abnormally decreased vagal tone in patients after myocardial infarction, whose reduced heart rate variability may be restored to normal.<>