According to recent electrophysiological discoveries, atrial fibrillation is triggered by ectopic beats which in most cases originate in the pulmonary veins, in extensions of left atrial myocardium upon these veins, so called myocardial sleeves. In the relevant literature it is stated that this anatomical structure was first described by Ferdinand Raeuschel in 1836 in the publication “De arteriarum et venarum structura“. This publication appeared as Raeuschel’s dissertation thesis at the faculty of medicine in Breslau (now Polish Wroclaw) at the department of physiology under the leadership of Jan Ev. Purkyně. In the introduction, the author thanks his tutor for introducing him into the problematic and for the continuous help, stating that all new discoveries in the dissertation should be ascribed to Purkyně. Thus, the description of myocardial sleeves of pulmonary veins appears as a yet further priority of the great Czech scientist.

        Key words: myocardial sleeves, J. Ev. Purkyně, atrial fibrillation, priorities, pulmonary veins.