Stokes-Adams Disease: Heart Block

Disturbances of the Heart
by Oliver T. Osborne, M.D.

(Page 17 of 21)

Stokes-Adams disease, or the Stokes-Adams syndrome, is a name applied to a combination of symptoms which was described by Stokes in 1846, and had been observed by Adams in 1827. The disease is characterized by bradycardia and cerebral attacks, either syncope or pseudo-apoplectic or convulsive attacks.

To understand the phenomena of this disease, it will be well to refer to the first chapter of this book. Until 1893, when His described the bundle of muscle fibers which is now known by his name, the transmission of the cardiac stimulus to contraction was not understood. It has been found, by studying the pathology of Stokes-Adams disease, as well as by clinically noting with instruments the contractions of different parts of the heart, that these slow heart beats are really due to interruptions of the impulse passing from auricle to ventricle through the bundle of His, and degeneration in this region is generally the cause of Stokes- Adams disease. The auricles often beat many times more frequently than the ventricles, even two or three times as frequently, and, of course, these auricular contractions are not transmitted to the arterial system, and the radial pulse notes only the contractions of the ventricles. The phrase that is used to describe this nontransmission of the auricular stimulus to the ventricles is "heart block."

While this disease almost invariably has a pathology, cases have occurred in which no lesion of the heart could be found, but it generally occurs coincidently with arteriosclerosis, in which the coronary arteries are more or less involved and the arterial system of the brain may be diseased. It occurs more frequently in men than in women, and in them mostly after middle, or in advanced, life. The previous history of the patient has often disclosed syphilis. The intermittence of the pulse may be regular or irregular, and may not be constant in the early stages of the disease; but when the disease is established, the rate of the pulse may be reduced to forty, thirty, or even twenty beats a minute, and it has been known to be even less. When these intermittences are regular, perhaps two beats to one intermittence, or three beats to one intermittence are the most frequent types. When the auricles also beat slowly, perhaps the vagiare for some reason overstimulated and thus inhibit the heart's activity.

The attacks of syncope are doubtless due to anemia of the medulla, because of the infrequent ventricular contractions. This anemia of the medulla and of the brain may also cause an epileptic seizure, or a partial paralytic seizure without any apparent paralysis. It is probable, however, that in these cases there may be coincident arterial disease in the brain. These sudden syncopal attacks are likely to occur when a patient suddenly rises from a reclining posture, especially if he has been asleep. Many persons whose circulation is none too strong may feel faint on suddenly rising, but in a person whose pulse is slow and the circulation weak the danger of causing anemia of the brain by the sudden erect posture is much increased. Slight faint turns are of frequent occurrence with these patients; or the faintness may be so rapid and so intense that the patient may drop in his tracks. Venous pulsation in the neck is generally marked, showing an impeded contraction of tile right auricle.

If the auricles are heard or found by instrumental readings to contract more frequently than the ventricles, the trouble is quite likely to be a heart block from disease in the heart itself, in the bundle of His. If the heart is slowed as a whole, the trouble might be due to diseased arteries or pressure from a growth, a gumma, perhaps, or other brain tumor in the region of the pons Varolii or medulla oblongata; or a hemorrhage into the fourth ventricle, causing pressure, could be the cause.

Treatment

The treatment of true Stokes-Adams disease is unsuccessful. If general arteriosclerosis is present, that condition should be treated. Digitalis would seem almost invariably contraindicated, although it is of value in extrasystoles without heartblock, or in conditions which are not Stokes-Adams disease; but if this disease was considered present, digitalis would probably do harm. Sometimes strychnin is of benefit.

Atropin has sometimes caused stimulation of the heart to more normal rapidity. Its benefit is generally only temporary, as most patients cannot take atropin regularly without having it cause a disagreeable drying of the throat and skin, a stimulation of the brain, and an undesired raising of the blood pressure, to say nothing of its action on the eyes.

The only value of the nitrites is when the blood pressure is high and the nitrite action is desired on that account.

Coffee or caffein often causes these hearts to become irritable; it certainly raises the blood pressure, and therefore is not generally advisable. Both tea and coffee should generally be prohibited.

During the acute faint attack, camphor is one of the best stimulants. Alcohol may be of benefit. If syphilis is a cause of the condition, iodids are always valuable. If syphilis is not a cause and arteriosclerosis is present, small doses of iodid given for a long period are beneficial, although it may not much reduce the blood pressure or decrease the plasticity of the blood. Iodid is a stimulant to the thyroid gland, and therefore it is on this account valuable.

An excellent stimulant to the heart is thyroid secretion or thyroid extract. Theoretically thyroid extracts should be the treatment for a slow-acting heart. It sometimes seems of benefit to these patients, but it often causes such nervous excitation and irritability as to preclude its use. The dose of thyroid for this purpose would be small, about one-fourth to one-half grain of the active substance three times a day. To be of any value, the preparation must be good.

Epinephrin has been shown by Hirtz to overcome experimental heart block. It is not clear just how it acts, but it could well be tried in heart block when the blood pressure is not too high. A few drops of an epinephrin solution 1:1,000 may be placed on the tongue, and repeated three times a day, or from 5 to 10 minims of a weaker solution may be given hypodermically.

The usual precautions against overeating, overdrinking, severe physical exercise, sudden movements, overuse of tobacco, etc., should all be urged on the patient. The disease is sooner or later fatal, although the patient may live some years. Death is generally sudden.

It is understood that this disease must he separated from the condition of bradycardia inherent in a few persons who have a slow pulse throughout their life, without any untoward symptoms.