Addition of specific antigen to the isolated atria of sensitized guinea pigs and of histamine to those of nonsensitized animals resulted in an increase of both frequency and amplitude of contraction and in the appearance of rhythmic activity in the isolated left atrium. On a quantitative basis the anaphylactic response looks like the effects of histamine in concentrations between 10~ and 10~ mM...

CONGENITAL cardiac defects involving the venous return to the heart and those affecting the partitioning of the atria should probably be considered as a group. The most commonly encountered and simplest to correct are defects in the interatrial septum of the ostium secundum type. Due to the lower resistance to emptying into the right ventricle from the two communicating atria, the shunt in such...

We used cytochalasin D to reduce contraction-related optical signals by inhibiting muscle contraction for the optical monitoring of action potentials, using a voltage-sensitive dye in isolated rat atrium preparations. The suppression of contraction-related signals was so strong that we concluded that this chemical is suitable for this purpose.

CONGENITAL cardiac defects involving the venous return to the heart and those affecting the partitioning of the atria should probably be considered as a group. The most commonly encountered and simplest to correct are defects in the interatrial septum of the ostium secundum type. Due to the lower resistance to emptying into the right ventricle from the two communicating atria, the shunt in such...

background recently, assessment of the atrial motion and deformation indices obtained via doppler myocardial imaging (dmi) has been proposed as a new method of exploring the atrial function. objective our aim was to assess the right atrial (ra) regional function using myocardial velocities, strain, and strain rate imaging (sri) and compare it with the function of the inter-atrial septum (ias) a...

To characterize the pump function of the left atrium, we determined the instantaneous pressure-volume relation of the isolated supported left atrium. A physiologic after-loading system for the low-pressure atrium was created by coupling it to a real-time computer-simulated ventricle and a simulated venous impedance network via a volume servo-pump. In 10 atria loaded with such systems, multiple ...