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Parchment heart (Osler)
PARCHMENT
HEART
HAROLD N.SEGALL,
(OSLER) M.D.
MONTREAL, QUE.
I
N REVISING the sixth edition (1905) of his textbook,2 Osler introduced the following brief paragraph in the chapter on dilatation of the heart: “Dilatation may be chronic, in which case it is associated with hypertrophy. Not always however; there is an extraordinary heart in the McGill College Museum showing a parchment-like thinning of the walls with uniform dilatation of all the chambers; in places in the right auricle and ventricle, only the epicardium remains.” This heart is now part of the Osler collection of specimens arranged by the late Dr. Maude E. Abbott during her curatorship of the museum. A recent thorough search of the museum records revealed no clue to the autopsy report concerned with this heart which represents a very rare abnormality, for no reference to such myocardial dilatation could be found in the ancient, the old, or the recent medical literature. As this heart is viewed, suspended in liquid, it resembles a large cyst, and its walls quiver when the jar is tapped or shaken gently. Indeed, only the demonstration of the four heart valves, the aorta and pulmonary artery, and the four cavities removes the initial doubt as to the specimen being that of a heart (Fig. 1). It now weighs 168 grams. The epicardium is thin. The cavities are greatI) dilated, the right more than the left. As Osler pointed out, the walls of the The interventricular auricles and ventricles are of “parchment-like” thinness. septum is the thickest portion and at its maximum measures 5 mm. If hypertrophy had developed commensurate with this degree of dilatation, the heart should have weighed about 1,000 grams. Judging by the two plaques of arteriosclerosis on the first portion of the aorta,it would seem that the person was in his forties or perhaps fifties. The coronary veins reveal no abnormalities. The Therecoronary arreries are patent, quite large, and free from arteriosclerosis. fore, the condition of the myocardium cannot be attributed to impairment in coronary circulation. The aorta and pulmonary artery are within the normal range in size, but somewhat thinner than expected in an adult. All valves are free from disease or congenital abnormality and seem adequate in size and shape to have performed their functions efficiently. The histological study* of the From
the Department
of Medicine,
McGill
University
and the Montreal
General
Hospital,
Mow
treal. Presented at Received for *I am greatly logical slides and Pathology, McGill
the Inter-American Congress of Cardiology, Chicago, Ill., June, 1948. publication Aug. 1. 1950. indebted to Professor Lyman G. Duff for his kindness in making studies of the histofor permitting me to report this heart, which is now in his rare in the Depart,ment of TJniversity. 94%
SEGALL:
PARCHMENT
HEART
(OSLER)
949
myocardium of the ventricular walls and of the interventricular septum revealed no satisfactory clue to the disease. The architecture of the myocardium seemed to be normal: the details of muscle fibers were, however, vague.
Fig. l.-Two views of the heart with walls of parchment-like thinness; one view shows the interior of the right ventricle with the pulmonary artery and its valves and a portion of the tricuspid valve. Note the flat thin papillary muscle and the thin ventricular wall which in some parts consists of epicardium alone. The view which shows the interior of the left and part of the right ventricle demonstrates Note fenestration of the aortic valve, and two arteriosclerotic plaques in the that the right is larger. intima of the first portion of the aorta. Most of the auricular walls, and the ventricular walls in the vicinity of the cardiac apex, are transparent.
Osler recognized and pointed out the main remarkable feature of this heart: there is an extreme degree of dilatation without the hypertrophy that usually occurs. The absence of hypertrophy in this parchment-like heart poses the salient question about its pathogenesis. Starling’s law of the heart may, in part, account for the dilatation, but it does not adequately explain the apparently long duration of life of the subject. Indeed, at present, no technique exists for reproducing such thin myocardium in an experimental animal. Among the various mechanisms that merit consideration, dystrophy of myocardium
in a person with generalised muscular dystrophy offers the possibility. of an esplanation. That the right auricle and ventricle are larger than the left suggests an element of car pulmonale which may have been due to impairment in function of respiratory muscles. It is very regrettable that this specimen is not accompanied by an adequate Dr. Maude Abbott found it among a clinical history and autopsy protocol. group of specimens donated to the Museum by Osler during his Montreal period, 1874 to 1884, and she included it in the special exhibit of Osler’s contributions which she arranged in 1920. Dr. Abbott had no records belonging to it but recalled vaguely that this heart had been found in a man who had died suddenly. while walking up a rather- steep hill in Montreal. Osler visited the McGill Museum in February, 19&S,* and may have seen the specimen on this occasion, for he first mentions it in the sixth edition of his book which appeared in that year. Thus we are confronted with the fact, inherent in this specimen, that the myocardium may stretch to “parchment-like” thinness and continue to function. The etiology and the story of the evolution of this degree of dilatation can only be conjectured. Perhaps some form of general muscular dystrophy played the chief role in the processes which resulted in this condition. We know of no other similar case, nor of any experimental technique b>. which an analagous condition could be produced in animals. This specimen provides striking evidence in answer to the theoretical question, “How far can the process of dilatation of a human heart progress?” REFERENCES 1. 2.
McDermott, H. E., and Abbott, Maude: pany of Canada, Ltd., p. 90. Osler, Wm.: The Principles and Practice 82 co., p. 820.
A Memoir, of Medicine,
Toronto,
1941,
ed. 6, New
The
York,
Macmillan 1905,
Com-
I). Appleton
HEART
HAROLD N.SEGALL,
(OSLER) M.D.
MONTREAL, QUE.
I
N REVISING the sixth edition (1905) of his textbook,2 Osler introduced the following brief paragraph in the chapter on dilatation of the heart: “Dilatation may be chronic, in which case it is associated with hypertrophy. Not always however; there is an extraordinary heart in the McGill College Museum showing a parchment-like thinning of the walls with uniform dilatation of all the chambers; in places in the right auricle and ventricle, only the epicardium remains.” This heart is now part of the Osler collection of specimens arranged by the late Dr. Maude E. Abbott during her curatorship of the museum. A recent thorough search of the museum records revealed no clue to the autopsy report concerned with this heart which represents a very rare abnormality, for no reference to such myocardial dilatation could be found in the ancient, the old, or the recent medical literature. As this heart is viewed, suspended in liquid, it resembles a large cyst, and its walls quiver when the jar is tapped or shaken gently. Indeed, only the demonstration of the four heart valves, the aorta and pulmonary artery, and the four cavities removes the initial doubt as to the specimen being that of a heart (Fig. 1). It now weighs 168 grams. The epicardium is thin. The cavities are greatI) dilated, the right more than the left. As Osler pointed out, the walls of the The interventricular auricles and ventricles are of “parchment-like” thinness. septum is the thickest portion and at its maximum measures 5 mm. If hypertrophy had developed commensurate with this degree of dilatation, the heart should have weighed about 1,000 grams. Judging by the two plaques of arteriosclerosis on the first portion of the aorta,it would seem that the person was in his forties or perhaps fifties. The coronary veins reveal no abnormalities. The Therecoronary arreries are patent, quite large, and free from arteriosclerosis. fore, the condition of the myocardium cannot be attributed to impairment in coronary circulation. The aorta and pulmonary artery are within the normal range in size, but somewhat thinner than expected in an adult. All valves are free from disease or congenital abnormality and seem adequate in size and shape to have performed their functions efficiently. The histological study* of the From
the Department
of Medicine,
McGill
University
and the Montreal
General
Hospital,
Mow
treal. Presented at Received for *I am greatly logical slides and Pathology, McGill
the Inter-American Congress of Cardiology, Chicago, Ill., June, 1948. publication Aug. 1. 1950. indebted to Professor Lyman G. Duff for his kindness in making studies of the histofor permitting me to report this heart, which is now in his rare in the Depart,ment of TJniversity. 94%
SEGALL:
PARCHMENT
HEART
(OSLER)
949
myocardium of the ventricular walls and of the interventricular septum revealed no satisfactory clue to the disease. The architecture of the myocardium seemed to be normal: the details of muscle fibers were, however, vague.
Fig. l.-Two views of the heart with walls of parchment-like thinness; one view shows the interior of the right ventricle with the pulmonary artery and its valves and a portion of the tricuspid valve. Note the flat thin papillary muscle and the thin ventricular wall which in some parts consists of epicardium alone. The view which shows the interior of the left and part of the right ventricle demonstrates Note fenestration of the aortic valve, and two arteriosclerotic plaques in the that the right is larger. intima of the first portion of the aorta. Most of the auricular walls, and the ventricular walls in the vicinity of the cardiac apex, are transparent.
Osler recognized and pointed out the main remarkable feature of this heart: there is an extreme degree of dilatation without the hypertrophy that usually occurs. The absence of hypertrophy in this parchment-like heart poses the salient question about its pathogenesis. Starling’s law of the heart may, in part, account for the dilatation, but it does not adequately explain the apparently long duration of life of the subject. Indeed, at present, no technique exists for reproducing such thin myocardium in an experimental animal. Among the various mechanisms that merit consideration, dystrophy of myocardium
in a person with generalised muscular dystrophy offers the possibility. of an esplanation. That the right auricle and ventricle are larger than the left suggests an element of car pulmonale which may have been due to impairment in function of respiratory muscles. It is very regrettable that this specimen is not accompanied by an adequate Dr. Maude Abbott found it among a clinical history and autopsy protocol. group of specimens donated to the Museum by Osler during his Montreal period, 1874 to 1884, and she included it in the special exhibit of Osler’s contributions which she arranged in 1920. Dr. Abbott had no records belonging to it but recalled vaguely that this heart had been found in a man who had died suddenly. while walking up a rather- steep hill in Montreal. Osler visited the McGill Museum in February, 19&S,* and may have seen the specimen on this occasion, for he first mentions it in the sixth edition of his book which appeared in that year. Thus we are confronted with the fact, inherent in this specimen, that the myocardium may stretch to “parchment-like” thinness and continue to function. The etiology and the story of the evolution of this degree of dilatation can only be conjectured. Perhaps some form of general muscular dystrophy played the chief role in the processes which resulted in this condition. We know of no other similar case, nor of any experimental technique b>. which an analagous condition could be produced in animals. This specimen provides striking evidence in answer to the theoretical question, “How far can the process of dilatation of a human heart progress?” REFERENCES 1. 2.
McDermott, H. E., and Abbott, Maude: pany of Canada, Ltd., p. 90. Osler, Wm.: The Principles and Practice 82 co., p. 820.
A Memoir, of Medicine,
Toronto,
1941,
ed. 6, New
The
York,
Macmillan 1905,
Com-
I). Appleton