Synonyms:—Synchopexia; rapid heart; tachycardia paroxysmalis.

Definition:—A condition of rapid heart action due either to paralysis of the vaso-motor nerves, which results in deficient control of the motor apparatus, through imperfect action of the vagus, or, to undue stimulation of the sympathetic, which results in exalted or increased nerve influence and consequent violent action.

Etiology:—The condition occurs independently of organic disease of the heart. It is functional in character, and usually reflex in its origin, following those conditions which irritate the nervous system, and which induce palpitation; chronic indigestion, or taking of too large a quantity of nitrogenous food, or use of tea, coffee and tobacco. It is not uncommon to hysterical women, and will occur as a result of extreme grief, or fright, anger, or other cause of agitation, and from protracted muscular exercise. Irritation of the genito-urinary organs or reproductive system are common causes, as it is apt to occur at the menopause, or in either sex, from masturbation. Disease of the medulla, or spinal cord, tumors, aneurisms, or other serious chronic lesions may exercise an exciting influence.

Symptomatology:—While the condition may be paroxysmal, and occur suddenly, similar to attacks of palpitation, it is much more apt to develop somewhat gradually, not being observed until the heart is beating regularly at from one hundred to perhaps one hundred and twenty pulsations per minute. In typical cases there are no intermissions, or remissions, for days at a time; often running into weeks, with no cessation of the regular rapid beating. There may be no pain, but a general precordial distress, or sense of oppression in the chest and an inclination to press upon the chest, or to hold it with the hands. There is increased weakness, with trembling of- the limbs, and, perhaps, ultimate prostration. Sooner or later, vertigo occurs with some nausea and perhaps vomiting, tennitus aureum and some disturbances of vision. The patient at first is anxious and soon becomes restless and greatly disturbed over the condition; in severe cases there is a sense of impending dissolution and fear, with rcmch pallor. In paroxysmal cases the pulse is apt to be more rapid than in the form above described. In these it may begin with a pulse rate of one hundred and fifty beats per minute, increased later to, perhaps, two hundred or more. The oppression of the chest induces difficult breathing, and there may be some cyanosis, although pallor is not uncommon. Patients suffering from anemia or chlorosis are more liable to attacks of the paroxysmal form of the disease. In those cases resulting from overstimulation of the sympathetic, the pulse is small, hard, and inclined to be wiry and steadily rapid. In cases where paralysis of the vagus is the cause the pulse is small, easily compressible, rapid, and often very feeble, many times scarcely distinguishable. This condition is not necessarily accompanied with palpitation. It is often the case that the patient will describe a sensation of slowness of the heart action in tachycardia while by actual count it may be beating two hundred beats per minute.

Prognosis:—The condition is not necessarily a serious one. It may disappear spontaneously when the cause of its occurrence is removed, with no permanent impairment of the health or changes in the heart structure. In other cases, where the cause is not well defined, or remains undiscovered, the condition may last for several years. Death occurs from complications.

Treatment:—General attention to those conditions which induce tachycardia must be conducted in like manner to that suggested for palpitation. The two conditions, however, must, in direct treatment, have careful consideration. Those resulting from paralysis and deficient nerve action must be treated with stimulants and tonics; while those induced by sthenia, by undue stimulation, or exalted nerve action, must be treated by sedatives. I treated at one time a case of tachycardia in a hysterical young woman, in otherwise excellent health, strong, active and vigorous, in which the regular uniform pulsation at one hundred and forty beats per minute continued for eighteen months, and did not materially interfere with her daily occupation. In prescribing cactus for this case, it exercised its characteristic tonic and stimulating action and it thus increased the condition, although the dose given was small. It became necessary to put the patient upon gelsemium, an active nerve sedative, and the bromids. This class of patients will stand aconite and veratrum in physiological doses for protracted periods, if the appetite and digestion remain undisturbed. I have a case under observation at the present time in which there is exaltation of nerve force, the patient being strong and vigorous, in which this class of remedies is prescribed with satisfactory results. Where there is deficiency of nerve force that class of heart remedies which increase the strength of the nervous system and improve its nutrition must be selected. This class of cases will stand some stimulation also. Cactus will work nicely here, and small doses of nux vomica, or the strychnin arsenate, in frequently repeated doses of about 1/134 of a grain may be given. Those measures suggested for palpitation, with weakness, are applicable in this case and need not be reiterated in detail.

The Eclectic Practice of Medicine with especial reference to the Treatment of Disease, 1910, was written by Finley Ellingwood, M.D.