Owing to the recent advances in the methods of investigation of the physiology of the heart, many interesting studies have been recorded and numerous hitherto doubtful phenomena have been explained. Special attention has been paid to the disturbances of the heart in those conditions known as "heart block," "arrhythmia" and "hemisystole."
It is our intention to present briefly a clinical study showing the relation between the so-called dropped beat and pseudohemisystole. Hemisystole is a condition allied to cardia bigemina, in which, during the second beat of the heart, the left ventricle fails to contract. This phenomenon was first described by V. Leyden;1 Unverricht2 next showed the relation between cardia bigemina, hemisystole and systolia alternans. The relationship of these conditions is shown in the following outline taken from Sahli.3
Although hemisystole has been observed in the exposed hearts of animals, most authors deny the possibility of its occurrence