Tracing Atrial Fibrillation — 100 Years
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《新英格兰医药杂志》
Today, there is talk about an epidemic of atrial fibrillation, and physicians caring for patients with this common arrhythmia face a bewildering array of treatment options. Contrast this situation with that of 1900, when no one understood the arrhythmia's mechanism or realized that it occurred in humans. One hundred years ago, in 1906, two publications — one from the Netherlands and the other from the United States — revealed that the arrhythmia, then called "auricular fibrillation," did indeed affect humans, that it was in fact common in patients with heart disease, and that it could be identified by means of a new instrument, the electrocardiograph. These two articles marked a turning point in the history of atrial fibrillation. Their publication, along with subsequent reports and the development of electrocardiography, helped clinical investigators begin to solve a perplexing problem that physicians soon came to recognize as a common one.1,2
Around 1900, a few clinical investigators, notably James Mackenzie in Scotland and Karel Wenckebach in Holland, were studying cardiac arrhythmias with the use of arterial and venous pulse tracings. Pulse tracings reflect the consequences of cardiac contractions; they do not document the actual electrical impulses that stimulate the atria and ventricles to contract in the first place. In 1906, Arthur Cushny and Charles Edmunds, pharmacologists at the University of Michigan, published an article on "paroxysmal irregularity of the heart and auricular fibrillation."3 They concluded that atrial fibrillation, known to develop acutely in dogs under certain (open-chest) experimental conditions, could occur in humans.
In their article, Cushny and Edmunds described experiments they had performed in animals during the previous decade. Like a few other medical scientists interested in the heart, they had observed that the atria in anesthetized open-chest dogs were sometimes dilated and motionless. On closer visual inspection, and by placing a "myograph" directly on the atrium, they noted that the walls were in a state of "fibrillary contraction." Their report was prompted by the case of a 64-year-old woman who had undergone surgery at the University of Michigan Hospital 5 years earlier. On palpation, her pulse was very irregular; this finding was documented by arterial pulse tracings. Cushny kept the tracings and acknowledged that he had gained new insight into the woman's arrhythmia by reading recent articles by Mackenzie and Wenckebach.
Cushny and Edmunds speculated that the woman's totally irregular pulse was a manifestation of the same arrhythmia they had observed in some dogs — atrial fibrillation. Still, their conclusion was tentative, relying as it did on an analogy and indirect evidence provided by pulse tracings. The proof of this hypothesis would come from a recent invention, the electrocardiograph. This instrument of precision would revolutionize the diagnosis of heart disease and catalyze the creation of cardiology as a specialty.
Willem Einthoven had first reported his invention of the electrocardiograph in 1902. The instrument was a complex combination of a string galvanometer, a light source, projecting microscope lenses, a timer, a glass-plate photographic recording apparatus, and wires leading to saline-filled buckets. There was very little interest in electrocardiography, however, until 1906 — the year the report by Cushny and Edmunds came out — when Einthoven published a review article on the clinical value of the technique.4 The article's title, "Le Télécardiogramme," reflected the fact that electrical signals recorded from a patient's limbs (submerged in buckets filled with saline solution) were transmitted over specially insulated telephone wires from the Leiden University Hospital to Einthoven's 600-lb electrocardiograph machine, located a mile away in his physiology laboratory (see photograph).
A Volunteer Sitting with His Arms in Saline-Filled Tubs with Wires Connected to Einthoven's Electrocardiograph.
From Einthoven.4
Einthoven's 32-page article included 26 single-lead electrocardiogram strips recorded from persons without known heart disease, patients with valvular and other forms of heart disease, and dogs in which deep chloroform anesthesia had been used to induce conduction defects. In addition to examples of ventricular premature contractions, ventricular bigeminy, atrial flutter, and atrial and ventricular hypertrophy, Einthoven included a tracing depicting what we now recognize as atrial fibrillation, which he termed "pulsus inaequalis et irregularis" (see tracing). He did not, however, speculate in the article about the mechanism that caused the irregular QRS complexes and chaotic undulating baseline, nor did he describe the arrhythmia's clinical importance. Einthoven's article, in a sense the first atlas of electrocardiography, was published 2 years before the instrument began to be sold commercially. The cost and complexity of the early electrocardiographic apparatus delayed the diffusion of the technique. Moreover, Einthoven published many of his articles in Dutch and so reached a rather small readership, although some of his reports were published in English, French, or German, or occasionally in two languages. Although the electrocardiographic tracings spoke for themselves — without regard to the language of the surrounding text — most physiologists and physicians were ill equipped to decipher them.
"Pulsus Inaequalis et Irregularis."
From Einthoven.4
But the puzzle pieces were gradually being assembled. When Cushny returned to his native Scotland in 1906, he visited Mackenzie. A few years later, Mackenzie credited Cushny with suggesting to him that atrial fibrillation might be a distinct and clinically important arrhythmia. Together, the 1906 articles had provided clues that led clinical investigators on both sides of the English Channel to propose, 3 years later, that atrial fibrillation was a common arrhythmia in patients with cardiac disease. Carl Rothberger and Heinrich Winterberg, in Vienna, and Thomas Lewis, in London, came to this conclusion independently at about the same time. Lewis, a pioneer of electrocardiography in the English-speaking world, had become interested in the technique when he read "Le Télécardiogramme." In 1909, he installed an electrocardiograph in his laboratory at University College Hospital, London, and visited Einthoven's laboratory in Leiden.
Lewis was convinced that the electrocardiograph provided unique and useful information about cardiac function in health and disease. He used the new tool to dissect arrhythmias in ways that were not possible with the use of pulse tracings. In 1909, he published a preliminary report of his electrocardiographic studies in patients whose pulses were "continuously and extremely irregular."5 On the basis of his research, Lewis concluded that atrial fibrillation was "a common clinical condition." This brief report was followed by a long article published the next year in his new journal, Heart. Although Cushny published another article on atrial fibrillation in 1911, he then returned to his main interest of pharmacology. Rothberger and Winterberg continued to contribute to the development of electrocardiography and knowledge of arrhythmias. Einthoven, for his part, continued to publish articles demonstrating the value of the electrocardiograph as a research and clinical tool, contributing to the creation of cardiology as a specialty.
The history of any medical problem or technique consists of a series of observations, innovations, and inventions that lead to the recognition of a distinct disease or the development and manufacture of a new piece of equipment. The history of atrial fibrillation underscores the importance of collaboration among medical scientists, clinical investigators, and physicians in the discovery, refinement, and clinical application of new knowledge. Although there are now many options for treating atrial fibrillation, we still rely on the electrocardiogram to confirm the diagnosis.
Source Information
Dr. Fye is a professor of medicine and the history of medicine and the director of the Mayo Clinic Center for the History of Medicine, Mayo Clinic College of Medicine, Rochester, MN.
References
Fye WB. Disorders of the heartbeat: a historical overview from antiquity to the mid-20th century. Am J Cardiol 1993;72:1055-1070.
Fye WB. A history of the origin, evolution, and impact of electrocardiography. Am J Cardiol 1994;73:937-949.
Cushny AR, Edmunds CW. Paroxysmal irregularity of the heart and auricular fibrillation. In: Bulloch W, ed. Studies in pathology. Aberdeen, Scotland: University of Aberdeen, 1906:95-110.
Einthoven W. Le télécardiogramme. Arch Int Physiol 1906;4:132-164.
Lewis T. Auricular fibrillation: a common clinical condition. BMJ 1909;2:1528-1528.(W. Bruce Fye, M.D.)
Around 1900, a few clinical investigators, notably James Mackenzie in Scotland and Karel Wenckebach in Holland, were studying cardiac arrhythmias with the use of arterial and venous pulse tracings. Pulse tracings reflect the consequences of cardiac contractions; they do not document the actual electrical impulses that stimulate the atria and ventricles to contract in the first place. In 1906, Arthur Cushny and Charles Edmunds, pharmacologists at the University of Michigan, published an article on "paroxysmal irregularity of the heart and auricular fibrillation."3 They concluded that atrial fibrillation, known to develop acutely in dogs under certain (open-chest) experimental conditions, could occur in humans.
In their article, Cushny and Edmunds described experiments they had performed in animals during the previous decade. Like a few other medical scientists interested in the heart, they had observed that the atria in anesthetized open-chest dogs were sometimes dilated and motionless. On closer visual inspection, and by placing a "myograph" directly on the atrium, they noted that the walls were in a state of "fibrillary contraction." Their report was prompted by the case of a 64-year-old woman who had undergone surgery at the University of Michigan Hospital 5 years earlier. On palpation, her pulse was very irregular; this finding was documented by arterial pulse tracings. Cushny kept the tracings and acknowledged that he had gained new insight into the woman's arrhythmia by reading recent articles by Mackenzie and Wenckebach.
Cushny and Edmunds speculated that the woman's totally irregular pulse was a manifestation of the same arrhythmia they had observed in some dogs — atrial fibrillation. Still, their conclusion was tentative, relying as it did on an analogy and indirect evidence provided by pulse tracings. The proof of this hypothesis would come from a recent invention, the electrocardiograph. This instrument of precision would revolutionize the diagnosis of heart disease and catalyze the creation of cardiology as a specialty.
Willem Einthoven had first reported his invention of the electrocardiograph in 1902. The instrument was a complex combination of a string galvanometer, a light source, projecting microscope lenses, a timer, a glass-plate photographic recording apparatus, and wires leading to saline-filled buckets. There was very little interest in electrocardiography, however, until 1906 — the year the report by Cushny and Edmunds came out — when Einthoven published a review article on the clinical value of the technique.4 The article's title, "Le Télécardiogramme," reflected the fact that electrical signals recorded from a patient's limbs (submerged in buckets filled with saline solution) were transmitted over specially insulated telephone wires from the Leiden University Hospital to Einthoven's 600-lb electrocardiograph machine, located a mile away in his physiology laboratory (see photograph).
A Volunteer Sitting with His Arms in Saline-Filled Tubs with Wires Connected to Einthoven's Electrocardiograph.
From Einthoven.4
Einthoven's 32-page article included 26 single-lead electrocardiogram strips recorded from persons without known heart disease, patients with valvular and other forms of heart disease, and dogs in which deep chloroform anesthesia had been used to induce conduction defects. In addition to examples of ventricular premature contractions, ventricular bigeminy, atrial flutter, and atrial and ventricular hypertrophy, Einthoven included a tracing depicting what we now recognize as atrial fibrillation, which he termed "pulsus inaequalis et irregularis" (see tracing). He did not, however, speculate in the article about the mechanism that caused the irregular QRS complexes and chaotic undulating baseline, nor did he describe the arrhythmia's clinical importance. Einthoven's article, in a sense the first atlas of electrocardiography, was published 2 years before the instrument began to be sold commercially. The cost and complexity of the early electrocardiographic apparatus delayed the diffusion of the technique. Moreover, Einthoven published many of his articles in Dutch and so reached a rather small readership, although some of his reports were published in English, French, or German, or occasionally in two languages. Although the electrocardiographic tracings spoke for themselves — without regard to the language of the surrounding text — most physiologists and physicians were ill equipped to decipher them.
"Pulsus Inaequalis et Irregularis."
From Einthoven.4
But the puzzle pieces were gradually being assembled. When Cushny returned to his native Scotland in 1906, he visited Mackenzie. A few years later, Mackenzie credited Cushny with suggesting to him that atrial fibrillation might be a distinct and clinically important arrhythmia. Together, the 1906 articles had provided clues that led clinical investigators on both sides of the English Channel to propose, 3 years later, that atrial fibrillation was a common arrhythmia in patients with cardiac disease. Carl Rothberger and Heinrich Winterberg, in Vienna, and Thomas Lewis, in London, came to this conclusion independently at about the same time. Lewis, a pioneer of electrocardiography in the English-speaking world, had become interested in the technique when he read "Le Télécardiogramme." In 1909, he installed an electrocardiograph in his laboratory at University College Hospital, London, and visited Einthoven's laboratory in Leiden.
Lewis was convinced that the electrocardiograph provided unique and useful information about cardiac function in health and disease. He used the new tool to dissect arrhythmias in ways that were not possible with the use of pulse tracings. In 1909, he published a preliminary report of his electrocardiographic studies in patients whose pulses were "continuously and extremely irregular."5 On the basis of his research, Lewis concluded that atrial fibrillation was "a common clinical condition." This brief report was followed by a long article published the next year in his new journal, Heart. Although Cushny published another article on atrial fibrillation in 1911, he then returned to his main interest of pharmacology. Rothberger and Winterberg continued to contribute to the development of electrocardiography and knowledge of arrhythmias. Einthoven, for his part, continued to publish articles demonstrating the value of the electrocardiograph as a research and clinical tool, contributing to the creation of cardiology as a specialty.
The history of any medical problem or technique consists of a series of observations, innovations, and inventions that lead to the recognition of a distinct disease or the development and manufacture of a new piece of equipment. The history of atrial fibrillation underscores the importance of collaboration among medical scientists, clinical investigators, and physicians in the discovery, refinement, and clinical application of new knowledge. Although there are now many options for treating atrial fibrillation, we still rely on the electrocardiogram to confirm the diagnosis.
Source Information
Dr. Fye is a professor of medicine and the history of medicine and the director of the Mayo Clinic Center for the History of Medicine, Mayo Clinic College of Medicine, Rochester, MN.
References
Fye WB. Disorders of the heartbeat: a historical overview from antiquity to the mid-20th century. Am J Cardiol 1993;72:1055-1070.
Fye WB. A history of the origin, evolution, and impact of electrocardiography. Am J Cardiol 1994;73:937-949.
Cushny AR, Edmunds CW. Paroxysmal irregularity of the heart and auricular fibrillation. In: Bulloch W, ed. Studies in pathology. Aberdeen, Scotland: University of Aberdeen, 1906:95-110.
Einthoven W. Le télécardiogramme. Arch Int Physiol 1906;4:132-164.
Lewis T. Auricular fibrillation: a common clinical condition. BMJ 1909;2:1528-1528.(W. Bruce Fye, M.D.)