Of the recognized disorders of the cardiac mechanism, none possess greater interest than the paroxysmal tachycardias. This affection has been recognized as a clinical entity for more than thirty years, and the condition has been produced experimentally by various means. Two questions have recently been revived; one, concerning sites of origin, especially the possibility of a paroxysm arising at the sinoatrial node (nomotopic tachycardia) and the other, concerning the rôle of the extrinsic nerves of the heart. Herewith I wish to report six cases1 of paroxysmal tachycardia which illustrate the moot points and the variety of clinical conditions in which the disorder occurs.
REPORT OF CASES
—J. W., aged 19 years, student. This patient was first seen Dec. 30, 1919, when he came for examination because of unduly rapid and forceful heart action which frequently occurred following exercise. He says they have been present as long as he