Electrophysiological effects of ajmaline in isolated cardiac tissue.
The electrophysiological effects of increasing molar concentrations of ajmaline were studied in isolated cardiac tissue, including sino-atrial node and Purkinje fibre. Ajmaline produced significant shortening of the plateau of Purkinje fibre action potential associated with marked depression of dV/dt and directly measured conduction velocity. A negative chronotropic effect was noted both in the sinus node and in spontaneously beating Purkinje fibres. Ajmaline's major electrophysiological effect appears to be depression of Purkinje fibre conduction velocity.
D000200:Action Potentials / Q000187:drug effects*; D000404:Ajmaline / Q000494:pharmacology*; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects; D005260:Female; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D008297:Male; D009206:Myocardium / Q000166:cytology; D009431:Neural Conduction / Q000187:drug effects; D011690:Purkinje Fibers / Q000187:drug effects; D012032:Refractory Period, Electrophysiological / Q000187:drug effects; D012849:Sinoatrial Node / Q000187:drug effects; D013997:Time Factors
D000404:Ajmaline