Effect of adrenoblockers on slow (LF) waves in rabbit heart rate.

Propranolol and atenolol were used to examine the role of the adrenergic system in the genesis of slow HR variations (waves) in rabbits, the animals characterized by pronounced sympathetic influences. The control experiments were performed with physiological solution and long-term records in intact rabbits. The harmonic (spectrum) analysis was performed with fast Fourier transform. The adrenoblockers produced no decrease in the power of slow waves. The study did not found the sympathetic genesis of slow variations in rabbit HR.