Reflexes from the Gall Bladder to the Heart.

The sudden release of bile obtained by incising the gall bladder of a decerebrated or ether-anesthetized frog is almost invariably attended by an abrupt change in the rate and character of beating of the heart. The first event is a transient arrest of the entire heart lasting between 1 and 10 sec., almost always followed by a sinus bradycardia lasting from 1/2 to 10 min. Subsequently there is a return to the initial rate of beating although in a few instances progressive slowing, leading to excessive dilatation and permanent arrest, have been observed. Not infrequently the first event to be noted is a transient acceleration which precedes the slowing. The heart appears to beat much more forcibly with the inception of the slower rate. The latent interval for the reflex is a fraction of a second to a second or more. Electrocardiograms made from base-apex leads show the cessation of activity of the sinus and ventricular portions of the heart followed by increased amplitude of R and a rather characteristic inversion of T. That the changes in the initial and final ventricular complexes are not directly associated with the reflex are to be found in the repetition of electrical effects, following an occasional sinus block which appears spontaneously after the resumption of a normal rate of beating. Such an effect is quite comparable to aberrant complexes following premature beats in mammalian electrocardiograms. Prolongation of the PR interval does not occur and an extra-systolic arrythmia cannot definitely be determined in the electrograms. In the frog there is a specific reflex from the gall bladder to the heart which appears to have a vagal origin.