But all the elements of Copland's group are not of equal importance; two of them, at least, are pathognomonic. "The two constituent elements of the paroxysm," says Latham, are "the sense of dissolution and the pain." "Pain with one awful accompaniment may be everything." "This mixture of the sharpest pain with a feeling of instant death." According to Fothergill "the two prominent subjective phenomena are pain in the chest and a sense of impending death." Eulenburg and Guttmann include another element: "We regard the substernal pain, the feeling of anxiety, and the disturbance of the heart's action, as the essential symptoms of angina pectoris." Romberg notes the companionship of these two elements: "The patient attacked with angina pectoris is suddenly seized with a pain under the sternum in the neighborhood of the heart, accompanied by a sense of anxiety so intense as to induce a belief in the approach of death."
We have laid the emphasis of these various citations on the "essential symptoms" in order to assert, with equal emphasis, that their analogues occur in not only one case of _Latrodectus mactans_ poisoning. The præcordial pain is noted in Cases 1, 3, 4 and 5, and the sense of impending dissolution in Cases 1, 4 and 5. And that disturbance of the heart's action which Eulenburg and Guttmann consider an essential element is found in Cases 1, 2, 4 and 5; so that the _tout ensemble_ presented by Case 4 is corroborated.
Another important element, though it is one subject to variations, is the direction of the extension of the pain. It most generally extends to the left axilla, and down the arm to the fingers; as variations it sometimes affects the right axilla and the back of the head. In Cases 1 and 4 the spider poison followed the direction of the disease, and in Cases 4 and 5 it also affected the back of the head. In Case 1 it produced the numbness of the arm and hand that is sometimes observed in the diseases.
Copland includes "difficulty of breathing" amongst the elements of angina pectoris. Trousseau does not regard this difficulty as real. "Although patients think they are going to be suffocated during a paroxysm, the chest is normally resonant on percussion, and if it be auscultated as they draw in breath again vesicular breathing is heard everywhere." Watson says, "the patient is not necessarily out of breath. It is not dyspnoea that oppresses him; for he can, and generally does, breathe freely and easily." Stokes is decided: "Respiration is _secondarily_ affected; there may be slight dyspnoea or orthopnoea, with lividity of the face, yet by an effort of the will (if the patient dares to encounter the pang this commonly produces) the chest may be pretty freely expanded, and the breathing relieved for a brief space; dyspnoea is not a primary symptom of angina." Eulenburg and Guttmann say, "Our own experience leads us to adopt Parry's conclusion, that the changes in the respiration are principally, perhaps even solely, due to the pain." Bristowe speaks of the sufferer as "fearing to breathe." We can readily see that the "apnæa" observed by Dr. Semple in Cases 1 and 5 had physical origin, but in Case 4 he says "apnæa was extreme; the respiration only occasional--gasping." This shows to what an extreme extent the action of the spider poison had gone--even to implicating the diaphragm; and it is noteworthy that Anstie records a case of angina pectoris (_Neuralgia and its Counterfeits_, p. 67, London, 1871), in which "there was so marked a catching of the breath as to make it almost certain that there was a diaphragmatic spasm."