Quasi-trapezoidal pulses to selectively block the activation of intrinsic laryngeal muscles during vagal nerve stimulation.
The stimulation of the vagus nerve has been used as an anti-epileptic treatment for over a decade, and its use for depression and chronic heart failure is currently under investigation. Co-activation of the intrinsic laryngeal muscles may limit the clinical use of vagal stimulation, especially in the case of prolonged activation. To prevent this, the use of a selective stimulation paradigm has been tested in seven acute pig experiments. Quasi-trapezoidal pulses successfully blocked the population of the largest and fastest vagal myelinated fibers being responsible for the co-activation. The first response in the vagus compound action potential was reduced by 75 +/- 22% (mean +/- SD) and the co-activated muscle action potential by 67 +/- 25%. The vagal bradycardic effects remained unchanged during the selective block, confirming the leading role of thin nerve fibers for the vagal control of the heart. Quasi-trapezoidal pulses may be an alternative to rectangular pulses in clinical vagal stimulation when the co-activation of laryngeal muscles must be avoided.
Tosato
M
M
Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Aalborg University, Fredrik Bajersvej 7D, DK 9220, Aalborg East, Denmark. marco@hst.aau.dk
Yoshida
K
K
Toft
E
E
Struijk
J J
JJ
D000818:Animals; D004558:Electric Stimulation / Q000379:methods*; D005260:Female; D007821:Laryngeal Muscles / Q000294:innervation* / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology*; D009407:Nerve Block / Q000379:methods*; D013552:Swine; D014630:Vagus Nerve / Q000502:physiology*