CLINICAL ESSAYS.

ESSAY I.

ON SUBCLAVIAN MURMUR.

IN conducting auscultatory examinations of the chest, the physician now and then meets with a passing murmur under one or both clavicles. To the inexperienced, it is difficult to determine whether the sound is connected with respiration or with the circulation; for it obtains in many cases that the sound, which seems arterial, is so peculiarly associated with the respiratory act, that its source assumes a double character. The sound has been described by few authors, but it is known to most persons who are extensively engaged in stethoscopic inquiries. I once heard Dr. Kirkes read a concise paper on the subject; Dr. Sibson has also referred to the murmur in explanation of its origin; and Dr. Thorburn, in the British Medical Journal for June 18th, 1859, has entered into a description of it in a paper entitled "A Peculiar Auscultatory Phenomenon". Dr. Thorburn, in certain doubts which he offers as to the origin of the

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sound, expresses what is, I believe, a general feeling. I shall endeavour in the succeeding observations to clear up the obscurities of the phenomenon, and to exhibit it in its true and simple light. The importance of the labour, in a diagnostic sense, I cannot better explain than by stating the fact that, within the last three years, four cases have been referred to me as cases of aneurism in the thorax, which have proved on further examination to be nothing more than well marked examples of subclavian murmur; cases, as we shall hereafter see, very innocent in their nature when compared with aneurismal disease.

I will follow out the description of subclavian murmur from its history, as it is written in the natural facts.

OBSERVED FACTS AND ANALYSES.

In 1856, a young man came before me at the Royal Infirmary for Diseases of the Chest, complaining of great lassitude, thirst, flatulency, depression of spirits, and palpitation of the heart. He was a tall, thin, anæmic man, by trade a cabinet-maker, and evidently of an irritable and what is popularly called "nervous" temperament. On examining his chest, I was surprised to hear under each clavicle a sharp loud murmur, synchronous with the systole of the heart, and resembling closely an aneurismal bruit. Tracing the murmur downwards towards the heart, I found it becoming reduced; whilst over the heart it was absent altogether. Each cardiac sound was clear, well defined, and natural. I followed out the courses of

the carotid, axillary, and femoral arteries with the stethoscope, and found in them no murmur. Percussing the chest in the subclavian regions, I discovered perfect resonance; but, on placing my fingers over the subclavian artery on each side, there was a distinct fremitus with each pulsation of the vessel. The patient himself was conscious of this fremitus, describing it as a gentle thrill beneath the fingers. On returning to the stethoscope, and divesting the ear of the murmur, the pure respiratory sounds were audible at every point; but now a further fact came out, viz., that whenever a long inspiration was made and the breath was retained, or whenever a long expiration was made, then the specific arterial sound was lost. I brought this patient to many medical friends, who expressed various opinions as to the nature of the disease; ultimately, however, the evidence became conclusive that the murmur was produced by posterior pressure on the subclavian artery.

The case being for a long time under my care, I made many observations upon it. Amongst these, it was distinguishable that the murmur underwent modification, according to the position of the arm corresponding to the side examined. When the arm was brought down close to the body, the murmur was lost; as the limb was raised towards a right angle, the sound recurred; at a perfect right angle, it rose to its acme; but at an acute angle, made by raising the limb towards the head, the sound declined; and when the limb was quite vertical, it was nearly lost.

From the time I have named, until the present year, the patient was under observation. He recovered his health on the administration of steel and quinine, and followed his business until 1859; but the murmur was always present, being specially developed after any excitement, as after a sharp walk, or mental worry. The last time I saw this man, he was suffering from distinct indications of tubercular deposit in the apex of each lung. He left London for the country; and has returned, I am informed, so much improved, that he is able to follow his work.

The occurrence of this case led me carefully to investigate other patients for the same symptom. I soon found that the murmur was an accompaniment of certain special diseased conditions, more or less severe. Thus in 2,000 patients of all ages, 1,011 of whom were females, and 989 males, who came under my care at the Royal Infirmary for Diseases of the Chest, from the 11th of November, 1858, to the 17th of August, 1860, and each of whom underwent careful examination for the murmur, I found it well marked in 51 cases, i. e. in 2.55 per cent. Among the 51, the murmur was found in enormous preponderance in males; there being 48 of the male sex presenting it, and 3 only of the female. The youngest patient in whom the murmur was heard was one John Clark, a coppersmith by trade, eighteen years old; he was suffering from simple dyspepsia : the oldest patient was one Edward Butler, a carpenter, seventy-four years old; he was labouring under subacute bronchitis.

The 2,000 patients to whom reference has been made, came with various diseases; there were cases of phthisis, of chronic bronchitis, of anæmia, chronic pleurisy, different forms of heart-disease, thoracic aneurism, stricture of the oesophagus, dyspepsia, diabetes, empyema, spasmodic asthma, morbus Brightii, cirrhosis of the liver, and a long list more. But the murmur itself was met with in five diseased states only; viz., in chronic bronchitis; in phthisis (during the first and second stages); in anæmia; in dyspepsia; and in valvular disease of the heart.

The cases of bronchitis, chronic and subacute, in the total of 2,000, were 610 in number, males and females together. Subclavian murmur was well marked in 18 of these; viz., in 16 males, and in 2 females. The bronchial affection was generally of long standing, and the mischief wide spread. The marked signs of disease were not always in the lung of the side on which the murmur was most distinct. There were three cases of subacute bronchitis.

The total cases of phthisis subjected to examination were 669. Of this number, 431 were males, and 238 were females. The murmur was presented in 12 of these patients, all of them being males. The tubercular disease, at the period when the murmur was well marked, was situated in the apex of the lung on one or both sides; the murmur was most distinct in the early stages of tuberculosis.

There was one mixed case, in a man aged 23, in whom, with old standing bronchial disease, there was evidence of tubercular deposit in the apex of the