Modulation of Cardiac Arrhythmias by the Autonomic Nervous System

Previous studies have shown that automaticity and conduction in various cardiac tissues can be accelerated, decelerated, or suppressed completely (annihilated) by properly timed short bursts of vagal discharges [1, 12–15, 18, 23, 26, 28–30, 33]. Phase-resetting and annihilation of automaticity and conduction also can occur following the delivery of brief hyperpolarizing or depolarizing current pulses [3, 7–11]. These observations suggest that cardiac arrhythmias caused by automaticity or by conduction abnormalities may be modulated by phasic discharges of the autonomic nervous system.