Methods and apparatus for stimulating the right vagal nerve within a living
body via positioning an electrode portion of a lead proximate to the portion of
the vagus nerve where the right cardiac branch is located (e.g., near or within
an azygos vein, or the superior vena cava near the opening of the azygos vein)
and delivering an electrical signal to an electrode portion adapted to be implanted
therein. Stimulation of the right vagus nerve and/or the cardiac branch thereof
act to slow the atrial heart rate. Exemplary embodiments include deploying an expandable
or self-oriented electrode (e.g., a basket, an electrode umbrella, and/or an electrode
spiral electrode, electrode pairs, etc). Various dedicated and single-pass leads
are disclosed, as well as, various electrodes, and stabilization means. The methods
include preserving sinus rhythm, avoiding asystole, preserving A-V synchrony, automatically
determining parameter combinations that achieve these features, and further (in
one embodiment) automatically determining parameter combinations achieve these
features and reduce current drain.