Howat [Footnote: Howat: Am. Jour. Physiol., February, 1916.] has shown that nicotin causes serious disturbances of the reflexes of the skin of frogs.
Edmunds and Smith [Footnote: Edmunds and Smith: Jour. Lab. and Clin.
Med., February, 1916.] of Ann Arbor find that the livers of dogs have some power of destroying nicotin, but their studies did not show how tolerance to large doses of nicotin is acquired.
Neuhof [Footnote: Neuhof, Selian: Sino-Auricular Block Due to Tobacco Poisoning, Arch. Int. Med., May, 1916, p. 659.] describes a case of sino-auricular heart block due to tobacco poisoning.
Intermittent claudication has been noted from the overuse of tobacco, as well as cramps in the muscles and of the legs.
A long series of investigations of the action of tobacco on high school boys and students of colleges seems to show that the age of graduation of smokers is older than that of nonsmokers, and that smokers require disciplinary measures more frequently than nonsmokers.
Some years ago investigation was made by Torrence, of the Illinois State Reformatory, in which there were 278 boys between the ages of 10 and 15 years. Ninety-two percent of these boys had the habit of smoking cigaretes, and 85 percent were cla.s.sed as cigarete fiends.
The most important action of nicotin is on the circulation. Except during the stage when the person is becoming used to the tobacco habit, in which stage the heart is weakened and the vasomotor pressure lowered by his nausea and prostration, the blood pressure is almost always raised during the period of smoking.
The heart is frequently made more rapid and the blood pressure is certainly raised in an ordinary smoker, while even a novice may get at first an increase, but soon he may become depressed and have a lowering of the pressure. While a moderate smoker may have an increase of 10 mm. in blood pressure, an excessive smoker may show but little change. Perhaps this is because his heart muscle has become weakened. If the person"s blood pressure is high, the heart may not increase in rapidity during smoking, and if he is nervous beforehand and is calmed by his tobacco, the pulse will be slowed.
It has been shown that the blood pressure and pulse rate may be affected in persons sitting in a smoke-filled room, even though they themselves do not smoke. The length of time the increased pressure continues depends on the person, and it is this diminishing pressure that causes many to take another smoke. The heart is slowed by the action of nicotin on the vagi, as these nerves are stimulated both centrally and peripherally. An overdose of nicotin will paralyze the vagi. The heart action then becomes rapid and perhaps irregular. The heart muscle is first stimulated, and if too large a dose is taken, or too much in twenty-four hours, the muscle becomes depressed and perhaps debilitated. The consequence of such action on the heart muscle, sooner or later, is a dilation of the left ventricle if the overuse of the tobacco is continued.
There is, then, no possible opportunity for any discussion as to the action of tobacco on the circulation. Its action is positive, constantly occurs, and it is always to be considered. The only point at this issue is as to whether or not such an activity is of consequence to the individual. The active principle of tobacco is nicotin, besides which it contains an aromatic camphor-like substance, cellulose, resins, sugar, etc. Other products developed during combustion are carbon monoxid gas, a minute amount of prussic acid and in some varieties a considerable amount of furfurol, a poison. From any one cigar or cigaret but little nicotin is absorbed, else the user would be poisoned. It is generally considered that the best tobacco comes from Cuba, and in the United States from Virginia. While it has not been definitely shown that any stronger narcotic drug occurs in cigarets sold in this country, it still is of great interest to note that a user who becomes habituated to one particular brand will generally have no other, and the excessive cigaret-smoker will generally select the strongest brand of cigarets. The same is almost equally true of cigar smokers.
Besides the effect on the circulation, no one who uses tobacco can deny that it has a soothing, narcotic effect. If it did not have this quieting effect on the nervous system, the increased blood pressure would stimulate the cerebrum. Following a large meal, especially if alcohol has been taken, the blood vessels of the abdomen are more or less dilated by the digestion which is in process. During this period of la.s.situde it is possible that tobacco, through its contracting power, by raising the blood pressure in the cerebrum to the height at which the patient is accustomed, will stimulate him and cause him to be more able to do active mental work. On the other hand, if a person is nervously tired, irritable, or even muscularly weary, a cigar or several cigarets will increase his blood pressure, take away his circulatory tire, soothe his irritability, and stop temporarily his muscular pains or aches and muscle weariness. If the user of the tobacco has thorough control of his habit, is not working excessively, physically or mentally, has his normal sleep at night and therefore does not become weary from insomnia, he may use tobacco with sense and in the amount and frequency that is more or less harmless as far as he is concerned. If such a man, however, is sleepless, overworked or worried, if he has irregular meals or goes without his food, and has a series of "dinners," or drinks a good deal of alcohol, which gives him vasomotor relaxation, he finds a constantly growing need for a frequent smoke, and soon begins to use tobacco excessively. Or the young boy, stimulated by his a.s.sociates, smokes cigarets more and more frequently until he uses them to excess.
Just what creates the intense desire for tobacco to the habitue has not been quite decided, but probably it is a combination of the irritation in the throat, especially in inhalers; of the desire for the rhythmic puffing which is a general cerebral and circulatory stimulant; for the increased vasomotor tension which many a patient feels the need of; for the narcotic, sedative, quieting effect on his brain or nerves; for the alluring comfort of watching the smoke curl into the air or for the quiet, contented sociability of smoking with a.s.sociates. Probably all of these factors enter into the desire to continue the tobacco habit in those who smoke, so to speak, normally.
The abnormal smokers, or those who use tobacco excessively, have a more and more intense nervous desire or physical need of the narcotic or the circulatory stimulant effect of the tobacco, and, consequently, smoke more and more constantly. They are largely inhalers, and frequently cigaret fiends.
It is probable that tobacco smoked slowly and deliberately, when the patient is at rest, and when he is leading a lazy, inactive, nonhustling life, such as occurs in the warmer climates, is much less harmful than in our colder climates, where life is more active.
Something at least seems to demonstrate that cigaret smoking is more harmful in our climate than in the tropics.
It has been shown by athletic records and by physicians"
examinations of boys and young men in gymnasiums that perfect circulation, perfect respiration and perfect normal growth of the chest are not compatible with the use of tobacco during the growing period. It is also known that tobacco, except possibly in minute quant.i.ties, prevents the full athletic power, circulatorily and muscularly, of men who compete in any branch of athletics that requires prolonged effort.
The chronic inflammation of the pharynx and subacute or chronic irritation of the lingual tonsil, causing the tickling, irritating, dry cough of inhalers of tobacco, is too well known, to need description.
Many patients who oversmoke lose their appet.i.tes, have disturbances from inhibition of the gastric digestion, and may have an irregular action of the bowels from overstimulation of the intestines, since nicotin increases peristalsis. Such patients look sallow, grow thin and lose weight. These are the kind of patients who smoke while they are dressing in the morning, on the way to their meals, to and from their business, and not only before going to bed, but also after they are in bed. It might be a question as to whether such patients do not need conservators. The use of tobacco in that way is absolutely inexcusable, if the patient is not mentally warped.
Cancer of the mouth caused by smoking, blindness from the overuse of tobacco, muscular trembling, tremors, muscle cramps and profuse perspiration of the hands and feet are all recognized as being caused by tobacco poisoning, but such symptoms need not be further described here.
The reason for which physicians most frequently must stop their patients from using tobacco, however, is that the heart itself has become affected by the nicotin action. The heart muscle is never strengthened by nicotin, but is always weakened by excessive indulgence in nicotin, the nerves of the heart being probably disturbed, if not actually injured. The positive symptoms of the overuse of tobacco on the heart are attacks of palpitation on exertion lasting perhaps but a short time, sharp, stinging pains in the region of the heart, less firmness of the apex beat, perhaps irregularity of the heart, and cold hands and feet. Clammy perspiration frequently occurs, more especially on the hands. Before the heart muscle actually weakens, the blood pressure has been increased more or less constantly, perhaps permanently, until such time as the left ventricle fails. The left ventricle from tobacco alone, without any other a.s.signable cause, may become dilated and the mitral valve become insufficient. Before the heart has been injured to this extent the patient learns that he cannot lie on his left side at night without discomfort, that exertion causes palpitation, and that he frequently has an irregularly acting heart and an irregular pulse. He may have cramps in his legs, leg-aches and cold hands and feet from an imperfect systemic circulation. In this condition if tobacco is entirely stopped, and the patient put on digitalis and given the usual careful advice as to eating, drinking, exertion, exercise and rest, such a heart will generally improve, acquire its normal tone, and the mitral valve become again sufficient, and to all intents and purposes the patient becomes well.
On the other hand, a heart under the overuse of tobacco may show no signs of disability, but its reserve energy is impaired and when a serious illness occurs, when an operation with the necessary anesthesia must be endured or when any other sudden strain is put on this heart, it goes to pieces and fails more readily than a heart that has not been so damaged.
If a patient does not show such cardiac weakness but has high tension, the danger of hypertension is increased by his use of tobacco, and certainly in hypertension tobacco should be prohibited.
The nicotin is doing two things for him that are serious: first, it is raising his blood pressure, and second, it will sooner or later weaken his heart, which may be weakened by the high blood pressure alone. Nevertheless a patient who is a habitual user of tobacco and has circulatory failure noted more especially about or during convalescence from a serious illness, particularly pneumonia, may best be improved by being allowed to smoke at regular intervals and in the amount that seems sufficient. Such patients sometimes rapidly improve when their previous circulatory weakness has been a subject of serious worry. Even such patients who were actually collapsed have been saved by the use of tobacco.
Whether the tobacco in a given patient shall be withdrawn absolutely, or only modified in amount, depends entirely on the individual case. As stated above, no rule can be laid down as to what is enough and what is too much. Theoretically, two or three cigars a day is moderate, and anything more than five cigars a day is excessive; even one cigar a day may be too much.
MISCELLANEOUS DISTURBANCES
SIMPLE HYPERTROPHY
Like any other muscular tissue, the heart hypertrophies when it has more work to do, provided this work is gradually increased and the heart is not strained by sudden exertion. To hypertrophy properly the heart must go into training. This training is necessary in valvular lesions after acute endocarditis or myocarditis, and is the reason that the return to work must be so carefully graduated. When the heart is hypertrophied sufficiently and compensation is perfect, a reserve power must be developed by such exercise as represented by the Nauheim, Oertel or Schott methods. Anything that increases the peripheral resistance causes the left ventricle to hypertrophy.
Anything that increases the resistance in the lungs causes the right ventricle to hypertrophy. The right ventricle hypertrophy caused by mitral lesions has already been sufficiently discussed. The right ventricle also hypertrophies in emphysema, after repeated or prolonged asthma attacks, perhaps generally in neglected pleurisies with effusion, in certain kinds of tuberculosis, and whenever there is increased resistance in the lung tissue or in the chest cavity.
The term "simple hypertrophy" is generally restricted to hypertrophy of the left ventricle without any cardiac excuse--the hypertrophy by hypertension and hard physical labor. It is well recognized that it hypertrophies with hypertension and with chronic interst.i.tial nephritis. It also becomes hypertrophied when the subject drinks largely of liquid--water or beer--and overloads his blood vessels and increases the work the heart must do. This kind of hypertrophy develops slowly because the resistance in the circulation is gradual or intermittent. In athletes and in soldiers who are required to march long distances, hypertrophy generally occurs. This hypertrophy, if slowly developed by gradual, careful training, is normal and compensatory. In effort too long sustained, especially in those untrained in that kind of effort, and even in the trained if the effort is too long continued, the left ventricle will become dilated and the usual symptoms of that condition occur. Such dilatation is always more or less serious. It may be completely recovered from, and it may not be. Therefore it proper understanding of the physics of the circulation by the medical trainer of young men to decide whether or not one should compete in a prolonged effort, as a rowing race, for instance, is essential. It is wrong for any young athlete to have an incurable condition occur from compet.i.tion.
Sometimes simple hypertrophy of the left ventricle occurs from various kinds of conditions that increase the peripheral circulation. It may occur from oversmoking, from the mertisc of coffee aid tea, from certain kinds of physical labor, or from high tension mental work. It is a part of the story of hypertension. Many times such patients, as well as occasionally trained athletes, and sometimes patients with arteriosclerosis or chronic interst.i.tial nephritis complain of unpleasant throbbing sensations of the heart added to these sensations are a feeling of fulness in the head, flushing of the face, and possibly dizziness--all symptoms not only of hypertension but of too great cardiac activity. Various drugs used to stimulate the heart may cause this condition; when digitalis is given and is not indicated or is given in overdosage, these symptoms occur.
The treatment is simply to lower the diet, cause catharsis, give hot baths, stop the tobacco, tea and coffee, stop the drinking of large amounts of liquid at any one time, and administer bromids and perhaps nitroglycerin, when all the symptoms of simple hypertrophy will, temporarily at least, disappear.
If the heart is enlarged from hypertrophy, if it is the right ventricle that is the most hypertrophied, the apex is not only pushed to the left, but the beat may be rather diffuse, as the enlarged right ventricle will prevent the apex from acting close to the surface of the chest. If the left ventricle is the most hypertrophied, the apex is also to the left, but the impact is very decided and the aortic closure is accentuated.
SIMPLE DILATATION
The term "simple dilatation" may be applied to the dilatation of one or both ventricles when there is no valvular lesion and when the condition may not be called broken compensation. The compensation has been sufficiently discussed. Dilatation of the heart occurs when there is increased resistance to the outflow of the blood front the ventricle, or when the ventricle is overfilled with blood and the muscular wall is unable to compete with the increased work thrown on it. In other words, it may be weakened by myocarditis or fatty degeneration; or it may be a normal heart that has sustained a strain; or it may be a hypertrophied heart that has become weakened.
Heart strain is of frequent occurrence. It occurs in young men from severe athletic effort; it occurs in older persons from some severe muscle strain, and it may even occur from so simple an effort as rapid walking by one who is otherwise diseased and whose heart is unable to sustain even this extra work. All of the conditions which have been enumerated as causing simple hypertrophy may have dilatation as a sequence.
Degeneration and disturbance of the heart muscle and cardiac dilatation are found more and more frequently at an earlier age than such conditions should normally occur. Several factors are at work in causing this condition. In the first place, infants and children are now being saved though they may have inherited, or acquired, a diminished withstanding power against disease and against the strain and vicissitudes of adult life. Other very important factors in causing the varied fortes of cardiac disturbances are the rapidity and strenuousness of a business and social life, and compet.i.tive athletics in school and college, to say nothing of the oversmoking and excessive dancing of many.
The symptoms of heart strain, if the condition is acute, are those of complete prostration, lowered blood pressure, and a sluggishly, insufficiently acting heart. The heart is found enlarged, the apex beat diffuse and there may be a systolic blow at the mitral or tricuspid valve. Sometimes, although the patient recognizes that he has hurt himself and strained his heart, he is not prostrated, and the full symptoms do not occur for several hours or perhaps several days, although the patient realizes that he is progressively growing weaker and more breathless.
The treatment of this acute or gradual dilatation is absolute rest, with small doses of digitalis gradually but slowly increased, and when the proper dosage is decided on, administered at that dosage but once a day. Cardiac stimulants should not be given, except when faintness or syncope has occurred, and if strychnin is used, it should be in small closes. The heart nay completely recover its usual powers, but subsequently it is more readily strained again by any thoughtless laborious effort. The patient must be warned as carefully as though he had a valvular lesion and had recovered from a broken compensation, and his life should be regulated accordingly, at least for some months. If he is young, and the heart completely and absolutely recovers, the force of the circulation may remain as strong as ever.
Sometimes the heart strain is not so severe, and after a few hours of rest and quiet the patient regains complete cardiac power and is apparently as well as ever; but for some time subsequently his heart more easily suffers strain.
Chronic dilatation of the heart, However, perhaps not sufficient to cause edema, slowly and insidiously develops from persistent strenuosity, or from the insidious irritations caused by absorbed toxins due to intestinal indigestion. A fibrosis of the heart muscle and of the arterioles gradually develops, and the heart muscle sooner or later feels the strain.
It is now very frequent for the physician, in his office, to hear the patient say, "Doctor, I am not sick, but just tired," or, "I get tired on the least exertion." We do not carefully enough note the condition of the heart in our patients who are just "weary," or even when they show beginning cardiovascular-renal trouble.
The primary symptoms of this condition of myocardial weakening are slight dyspnea on least exertion; slight heart pain; slight edema above the ankles; often some increased heart rapidity, sometimes without exertion; after exertion the heart does not immediately return to its normal frequency; slight dyspnea on least exertion after eating; flushing of the face or paleness around the mouth, and more or less dilatation of the veins of the hands. All of these are danger signals which may not be especially noted at first by the individual; but, if he presents himself to his physician, such a story should cause the latter not only to make a thorough physical examination, but also to note particularly the size of the heart.
It a roentgenographic and fluoroscopic examination cannot be made, careful percussion, noting the region of the apex beat, noting the rapidity and action of the heart on sitting, standing and lying, and noting the length of time it takes while resting, after exertion, for the speed of the heart to slacken, will show the heart strength.
Slight dilatation being diagnosed, the treatment is as follows
1. Rest, absolute if needed, and the prohibition of all physical exercise and of all business cares.
2. Reduction in the amount of food, which should be of the simplest.
Alcohol should be stopped, and the amount of tea, coffee and tobacco reduced.
3. If medication is needed, strychnin sulphate, 1/40, or 1/30 grain three times a day, acid the tincture of digitalis in from 5 to 10 drop doses twice a day will aid the heart to recover its tone.
Such treatment, when soon applied to a slowly dilating and weakening heart, will establish at least a temporary cure and will greatly- prolong life.
If these hearts are not diagnosed and properly treated, such patients are liable to die suddenly of "heart failure," of acute stomach dilatation, or of angina pectoris. Furthermore, unsuspected dilated hearts are often the cause of sudden deaths during the first forty-eight hours of pneumonia.
Small doses of digitalis are sufficient in these early cases. If more heart pain is caused, the dose of digitalis is too large, or it is contraindicated. Digitalis need not be long given in this condition, especially as Cohen, Fraser and Jamison [Footnote: Cohen, Fraser and Jamison: Jour. Exper. Med., June, 1915.] have shown by the electrocardiograph that its effect on the heart may last twenty- two days, and never lasts a shorter time than five days. They also found that when digitalis is given by the mouth, the electrocardiograph showed that its full activity was not reached until from thirty-six to forty-eight hours after it had been taken.