Etymologically tachycardia means rapid heart. There are two forms of rapid heart, that which is constant and that which occurs in periodical attacks. It is for this latter that the term tachycardia has been more particularly used, though occasionally the adjective paroxysmal is attached to it to indicate the intermittent character of the affection. With regard to the persistent type of rapid heart something deserves to be said, however, because patients' minds are often seriously disturbed by them. Often it has existed for years, sometimes is known to be a family trait and probably has existed from childhood, yet the discovery of it may be delayed until some pathological condition develops, calling for the attendance of a physician who may be needlessly alarmed and in turn alarm his patient by his recognition of it. The cause for this persistent rapid pulse is not well known and is difficult to determine. Heredity, as has been suggested, sometimes plays an important role in it. Certain families have one or more members in each generation with rapid hearts. Whenever persistent rapid heart is a family trait the patient can be assured, as a rule, without hesitation, that the general prognosis of the case is that of the lives of the rest of the family. Usually the symptom seems to mean nothing as regards early mortality or any special tendency to morbidity.

Favorable Prognosis.—While a rapid pulse often and indeed usually has some serious significance, it must not be forgotten that it may be an individual peculiarity and be quite compatible with long life and hard work. One of the first patients that I saw as a physician had a pulse between ninety-six and one hundred. As there was a slight tendency to irregular heart action also, I was inclined to think that there must be some cardiac muscle trouble. There was apparently no valve lesion. He told me that a physician ten years before had noted his rapid pulse and had made many inquiries about it which rather seriously disturbed him. He had been an extremely healthy man during his fifty-five years of life and there seemed no reason to conclude, since his rapid pulse had been in existence for ten years, that it meant anything serious. He has now lived well beyond the age of seventy and still has a pulse always above ninety. Contrary to what might be thought, he is an extremely placid, unexcitable individual, who, under ordinary circumstances, will probably live for many years to come. He has no family history of tachycardia, though there is a history of rather nervous irritable hearts in other members for two generations.

An interesting case of this kind came under my observation about fifteen years ago in a clergyman whose pulse was never below ninety, and who on slight excitement, or after a rapid walk, or after a heavy meal, would have a pulse of 120. He knew that it was a family trait, his father having had it yet living to be past seventy. He gave a history of its having been recognized in his own person more than twenty years before. His general health, however, was excellent. He took long walks and, indeed, pedestrian excursions {341} were his favorite exercise. He was able to go up flights of stairs rather rapidly without discomfort. He was the pastor in a tenement house district so he had plenty of opportunity for such exertion. Infections of any kind, colds and the like, disturbed his pulse very much, if the ordinary standard was taken, but it was not irregular and the increase in rapidity was probably only proportionate to the original height of the pulse in his case. After all, as the normal pulse of sixty to seventy rises to between ninety and one hundred even in a slight fever, it is not surprising if a pulse normally above ninety should rise fifty per cent. to one hundred and thirty-five under similar conditions. He is now well past sixty, after over thirty-five known years—and probably longer—of a pulse above ninety, yet he is in excellent general health and promises, barring accident, to live beyond seventy.

Some ten years ago I first saw another of these cases of fast heart, with a family history of the affection in a preceding generation. He was a man who had not taken good care of himself and had been especially over-indulgent in alcohol. This indulgence consisted not in rare sprees but in the persistent daily taking of large quantities of straight whiskey. In spite of warnings, he has not given up this habit; yet at the age of sixty-five he is apparently in good health and is able to fulfill the duties of a rather exacting occupation.

Persistent rapid pulse often occurs in connection with some disturbance of the thyroid gland. The larval forms of Graves' disease occur particularly in young persons, though they are sometimes seen in those beyond middle life. They seem to be due to a lack of development of the thyroid in consonance with the rest of the tissues, though occasionally, especially after the menopause, they seem to be connected with some degenerative process out of harmony for the moment with other forms of degeneration. When they occur in young persons they may, of course, represent the beginning of incipient Graves' disease, but they are often only functional and the symptoms may pass away entirely. The rapid heart action may come and go, though usually the attacks last for some days and oftener for a week or more at a time.

Paroxysmal Tachycardia.—A rapid heart may not only exist continuously in an individual for many years without any impairment of general health or shortening of life, but there may be spasmodic attacks of this condition with the pulse running up so high as to deserve the name of paroxysmal tachycardia; yet the patient may live for many years and die from some affection not connected with his heart. Perhaps the most remarkable case of this kind on record is that reported by Prof. H. C. Wood of Philadelphia. The patient was a physician in his later eighties when he came under Dr. Wood's observation. His first attack of paroxysmal tachycardia came in his thirty-seventh year. These attacks had apparently always been similar to those he then suffered and were abrupt in onset and the pulse would rise rapidly to 200 a minute. The original prognosis had been, of course, very unfavorable. The physician had outlived all the prophets of evil in his case, however. When large numbers of these cases were studied, it was found that they always last more than ten years, and, while heart failure in such cases is reported, it is doubtful if this occurs with more frequency in these patients as the result of strong reflexes than in the general run of patients, for it must not be forgotten that there is a certain average number of deaths from so-called heart failure in people supposed to be in good health.{342}

In connection with these attacks of paroxysmal tachycardia, there often come intense feelings of depression and even local disturbances of circulation. It is probable that in many cases there is a serious factor at work. MacKenzie has suggested that they are due to nodal rhythm of the heart in which the heart beat does not start at the root of the sinus as is usual, but in some other portion of the musculature and as a consequence there is serious interference with the regular rhythmic action. In a number of cases of heart failure, tachycardia becomes a prominent feature and it is probably due to some such disturbance as this. Such cases often look very serious for a time, yet frequently recover completely after a brief interval. This must not disguise the fact, however, that many of these cases, especially where acute dilatation of the heart can be demonstrated, are extremely dangerous and may end in a sudden fatal termination. The patient seems so much prostrated that occasionally the physician may doubt whether it is worth while to put him to the bother necessary in order to diagnose the acute dilatation of the heart. It always is, however. If it were nothing else but the occupation of the patient's attention with the doctor's manipulations, as far as that is possible, the effect would be good, besides whatever irritation may be caused to the heart muscle itself by percussion of the heart area will probably do mechanical good.

The most important element evidently is that the patient shall not be allowed to lose courage or to think that nothing can be done for him. Something must be done, and a combination of swallowing movements and deep breathing, as far as that is possible, with counter-irritation through the chest wall should be carried out. Drugs also should be employed and the aroma of strong coffee with the irritating effect of ammonia upon the nostrils should be employed. These act upon the vagus so as to stimulate the heart, but above all they act upon the mind, and nothing so stimulates the heart as reawakened hope.