Although the clinical syndrome, known as angina pectoris, has been carefully studied by many observers it seems fair to assert that the exact condition of the heart or the sequence of events occurring during an anginal attack is unknown. It is true that theories have been promulgated, but their very multiplicity is good evidence that there is no general agreement in the profession as to the cause of angina pectoris. It is my purpose in this paper to offer a conception of angina pectoris which seems, may I say, to contain a more satisfactory explanation of this dread condition. I hasten to deny that I hold as original all aspects of the theory to be presented below.
It is well at this point to pause to define what is meant by the term angina pectoris. Typical angina pectoris is characterized1 by paroxysmal attacks of pain over the sternum, often