Mice, rats, rabbits, finches, pigeons, and roosters were exposed to +Gz, minus Gz, and minus Gx inertial forces due to acceleration. The range of body weight of all animals was from 14 g to 1.6 kg. The magnitude of G and duration of exposure time were within 130 G and 20 min and the average rate of changes of G was 2.8 G/s. The G tolerances of these animals were compared with one another at 50% mortality. The tolerance of each species was expressed as the area under the tolerance curve. Changes of tolerance were obtained by the changes of direction of G force. The tolerance ratio of minus Gz to +Gz force was 0.58 and that of minus Gx to +Gz was 2.12. Body weight was inversely related to the threshold G-value at which animals are resistant to the prolonged acceleration.
Arrhythmias are abnormalities in heart rhythms, which can be either too fast or too slow. They can result from abnormalities of the initiation of an impulse or impulse conduction or a combination of both. Here is the latest research on arrhythmias.