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A Concise History of the ECG: Difference between revisions
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[[Image:einthoven.jpg|thumb|Willem Einthoven]] | [[Image:einthoven.jpg|thumb|Willem Einthoven]] | ||
[[Image:Einthoven_ECG.jpg|thumb|An electrocardiograph as used by Einthoven]] | [[Image:Einthoven_ECG.jpg|thumb|An electrocardiograph as used by Einthoven]] | ||
'''1895''' Einthoven, using an improved electrometer and a correction formula developed independently of Burch, distinguishes five deflections which he names P, Q, R, S and T. <cite> | '''1895''' Einthoven, using an improved electrometer and a correction formula developed independently of Burch, distinguishes five deflections which he names P, Q, R, S and T. <cite>Einthoven2</cite> | ||
Why PQRST and not ABCDE? The four deflections prior to the correction formula were labelled ABCD and the 5 derived deflections were labelled PQRST. The choice of P is a mathematical convention (as used also by Du Bois-Reymond in his galvanometer's 'disturbance curve' 50 years previously) by using letters from the second half of the alphabet. N has other meanings in mathematics and O is used for the origin of the Cartesian coordinates. In fact Einthoven used O ..... X to mark the timeline on his diagrams. P is simply the next letter. A lot of work had been undertaken to reveal the true electrical waveform of the ECG by eliminating the damping effect of the moving parts in the amplifiers and using correction formulae. If you look at the diagram in Einthoven's 1895 paper you will see how close it is to the string galvanometer recordings and the electrocardiograms we see today. The image of the PQRST diagram may have been striking enough to have been adopted by the researchers as a true representation of the underlying form. It would have then been logical to continue the same naming convention when the more advanced string galvanometer started creating electrocardiograms a few years later. | Why PQRST and not ABCDE? The four deflections prior to the correction formula were labelled ABCD and the 5 derived deflections were labelled PQRST. The choice of P is a mathematical convention (as used also by Du Bois-Reymond in his galvanometer's 'disturbance curve' 50 years previously) by using letters from the second half of the alphabet. N has other meanings in mathematics and O is used for the origin of the Cartesian coordinates. In fact Einthoven used O ..... X to mark the timeline on his diagrams. P is simply the next letter. A lot of work had been undertaken to reveal the true electrical waveform of the ECG by eliminating the damping effect of the moving parts in the amplifiers and using correction formulae. If you look at the diagram in Einthoven's 1895 paper you will see how close it is to the string galvanometer recordings and the electrocardiograms we see today. The image of the PQRST diagram may have been striking enough to have been adopted by the researchers as a true representation of the underlying form. It would have then been logical to continue the same naming convention when the more advanced string galvanometer started creating electrocardiograms a few years later. | ||
'''1897''' Clement Ader, a French electrical engineer, reports his amplification system for detecting Morse code signals transmitted along undersea telegraph lines. It was never intended to be used as a galvanometer. Einthoven later quoted Ader's work but seems to have developed his own amplification device independently. Ader | '''1897''' Clement Ader, a French electrical engineer, reports his amplification system for detecting Morse code signals transmitted along undersea telegraph lines. It was never intended to be used as a galvanometer. Einthoven later quoted Ader's work but seems to have developed his own amplification device independently. <cite>Ader</cite> | ||
'''1899''' Karel Frederik Wenckebach publishes a paper "On the analysis of irregular pulses" describing impairment of AV conduction leading to progressive lengthening and blockage of AV conduction in frogs. This will later be called Wenckebach block (Mobitz type I) or Wenckebach phenomenon. | '''1899''' Karel Frederik Wenckebach publishes a paper "On the analysis of irregular pulses" describing impairment of AV conduction leading to progressive lengthening and blockage of AV conduction in frogs. This will later be called Wenckebach block (Mobitz type I) or Wenckebach phenomenon. | ||
'''1899''' Jean-Louis Prevost, Professor of Biochemistry, and Frederic Batelli, Professor of Physiology, both of Geneva discover that large electrical voltages applied across an animal's heart can stop ventricular fibrillation. Prevost | '''1899''' Jean-Louis Prevost, Professor of Biochemistry, and Frederic Batelli, Professor of Physiology, both of Geneva discover that large electrical voltages applied across an animal's heart can stop ventricular fibrillation. <cite>Prevost</cite> | ||
'''1901''' Einthoven invents a new galvanometer for producing electrocardiograms using a fine quartz string coated in silver based on ideas by Deprez and d'Arsonval (who used a wire coil). His "string galvanometer" weighs 600 pounds. Einthoven acknowledged the similar system by Ader but later (1909) calculated that his galvanometer was in fact many thousands of times more sensitive. | '''1901''' Einthoven invents a new galvanometer for producing electrocardiograms using a fine quartz string coated in silver based on ideas by Deprez and d'Arsonval (who used a wire coil). His "string galvanometer" weighs 600 pounds. Einthoven acknowledged the similar system by Ader but later (1909) calculated that his galvanometer was in fact many thousands of times more sensitive. <cite>Einthoven3</cite> | ||
'''1902''' Einthoven publishes the first electrocardiogram recorded on a string galvanometer. Einthoven W. Galvanometrische registratie van het menschilijk electrocardiogram. In: Herinneringsbundel Professor S. S. Rosenstein. Leiden: Eduard Ijdo, 1902:101-107 | '''1902''' Einthoven publishes the first electrocardiogram recorded on a string galvanometer. Einthoven W. Galvanometrische registratie van het menschilijk electrocardiogram. In: Herinneringsbundel Professor S. S. Rosenstein. Leiden: Eduard Ijdo, 1902:101-107 | ||
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'''1920''' Hubert Mann of the Cardiographic Laboratory, Mount Sinai Hospital, describes the derivation of a 'monocardiogram' later to be called 'vectorcardiogram'. Mann H. A method of analyzing the electrocardiogram. Arch Int Med 1920;25:283-294 | '''1920''' Hubert Mann of the Cardiographic Laboratory, Mount Sinai Hospital, describes the derivation of a 'monocardiogram' later to be called 'vectorcardiogram'. Mann H. A method of analyzing the electrocardiogram. Arch Int Med 1920;25:283-294 | ||
'''1920''' Harold Pardee, New York, publishes the first electrocardiogram of an acute myocardial infarction in a human and describes the T wave as being tall and "starts from a point well up on the descent of the R wave". Pardee | '''1920''' Harold Pardee, New York, publishes the first electrocardiogram of an acute myocardial infarction in a human and describes the T wave as being tall and "starts from a point well up on the descent of the R wave". <cite>Pardee</cite> | ||
'''1924''' Willem Einthoven wins the Nobel prize for inventing the electrocardiograph. | '''1924''' Willem Einthoven wins the Nobel prize for inventing the electrocardiograph. | ||
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'''1926''' A doctor from the Crown Street Women's Hospital in Sydney, who wished to remain anonymous, resuscitates a new-born baby with an electrical device later called a 'pacemaker'. The doctor wanted to remain anoymous because of the controversy surrounding research that artificially extended human life. | '''1926''' A doctor from the Crown Street Women's Hospital in Sydney, who wished to remain anonymous, resuscitates a new-born baby with an electrical device later called a 'pacemaker'. The doctor wanted to remain anoymous because of the controversy surrounding research that artificially extended human life. | ||
'''1928''' Ernstine and Levine report the use of vacuum-tubes to amplify the electrocardiogram instead of the mechanical amplification of the string galvanometer. Ernstine | '''1928''' Ernstine and Levine report the use of vacuum-tubes to amplify the electrocardiogram instead of the mechanical amplification of the string galvanometer. <cite>Ernstine</cite> | ||
'''1928''' Frank Sanborn's company (founded 1917 and acquired by Hewlett-Packard in 1961 and since 1999, Philips Medical Systems) converts their table model electrocardiogram machine into their first portable version weighing 50 pounds and powered by a 6-volt automobile battery. | '''1928''' Frank Sanborn's company (founded 1917 and acquired by Hewlett-Packard in 1961 and since 1999, Philips Medical Systems) converts their table model electrocardiogram machine into their first portable version weighing 50 pounds and powered by a 6-volt automobile battery. | ||
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'''1930''' Wolff, Parkinson and White report an electrocardiographic syndrome of short PR interval, wide QRS and paroxysmal tachycardias. Wolff L, Parkinson J, White PD. Bundle branch block with short P-R interval in healthy young people prone to paroxysmal tachycardia. Am Heart J 1930;5:685. Later, when other published case reports were examined for evidence of pre-excitation, examples of 'Wolff Parkinson White' syndrome were identified which had not been recognised as a clinical entity at the time. The earliest example was published by Hoffmann in 1909. Von Knorre GH. The earliest published electrocardiogram showing ventricular preexcitation. Pacing Clin Electrophysiol. 2005 Mar;28(3):228-30 | '''1930''' Wolff, Parkinson and White report an electrocardiographic syndrome of short PR interval, wide QRS and paroxysmal tachycardias. Wolff L, Parkinson J, White PD. Bundle branch block with short P-R interval in healthy young people prone to paroxysmal tachycardia. Am Heart J 1930;5:685. Later, when other published case reports were examined for evidence of pre-excitation, examples of 'Wolff Parkinson White' syndrome were identified which had not been recognised as a clinical entity at the time. The earliest example was published by Hoffmann in 1909. Von Knorre GH. The earliest published electrocardiogram showing ventricular preexcitation. Pacing Clin Electrophysiol. 2005 Mar;28(3):228-30 | ||
'''1930''' Sanders first describes infarction of the right ventricle. Sanders | '''1930''' Sanders first describes infarction of the right ventricle. <cite>Sanders</cite> | ||
'''1931''' Charles Wolferth and Francis Wood describe the use of exercise to provoke attacks of angina pectoris. They investigated the ECG changes in normal subjects and those with angina but dismissed the technique as too dangerous "to induce anginal attacks indiscriminately". Wood | '''1931''' Charles Wolferth and Francis Wood describe the use of exercise to provoke attacks of angina pectoris. They investigated the ECG changes in normal subjects and those with angina but dismissed the technique as too dangerous "to induce anginal attacks indiscriminately". <cite>Wood</cite> | ||
'''1931''' Dr Albert Hyman patents the first 'artificial cardiac pacemaker' which stimulates the heart by using a transthoracic needle. His aim was to produce a device that was small enough to fit in a doctor's bag and stimulate the right atrial area of the heart with a suitably insulated needle. His experiments were on animals. His original machine was powered by a crankshaft (it was later prototyped by a German company but was never successful). "By March 1, 1932 the artificial pacemaker had been used about 43 times, with a successful outcome in 14 cases." It was not until 1942 that a report of its successful short term use in Stokes-Adams attacks was presented. Hyman AS. Resuscitation of the stopped heart by intracardial therapy. Arch Intern Med. 1932;50:283 | '''1931''' Dr Albert Hyman patents the first 'artificial cardiac pacemaker' which stimulates the heart by using a transthoracic needle. His aim was to produce a device that was small enough to fit in a doctor's bag and stimulate the right atrial area of the heart with a suitably insulated needle. His experiments were on animals. His original machine was powered by a crankshaft (it was later prototyped by a German company but was never successful). "By March 1, 1932 the artificial pacemaker had been used about 43 times, with a successful outcome in 14 cases." It was not until 1942 that a report of its successful short term use in Stokes-Adams attacks was presented. Hyman AS. Resuscitation of the stopped heart by intracardial therapy. Arch Intern Med. 1932;50:283 | ||
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'''1944''' Young and Koenig report deviation of the P-R segment in a series of patients with atrial infarction. Young EW, Koenig BS. Auricular infarction. Am Heart J. 1944;28:287. | '''1944''' Young and Koenig report deviation of the P-R segment in a series of patients with atrial infarction. Young EW, Koenig BS. Auricular infarction. Am Heart J. 1944;28:287. | ||
'''1947''' Gouaux and Ashman describe an observation that helps differentiate aberrant conduction from ventricular tachycardia. The 'Ashman phenomenon' occurs when a stimulus falls during the relative or absolute refractory period of the ventricles and the aberrancy is more pronounced. In atrial fibrillation with aberrant conduction this is demonstrated when the broader complexes are seen terminating a relatively short cycle that follows a relatively long one. The QRS terminating the shorter cycle is conducted 'more aberrantly' because it falls in the refractory period. The aberrancy is usually of a RBBB pattern. Gouaux | '''1947''' Gouaux and Ashman describe an observation that helps differentiate aberrant conduction from ventricular tachycardia. The 'Ashman phenomenon' occurs when a stimulus falls during the relative or absolute refractory period of the ventricles and the aberrancy is more pronounced. In atrial fibrillation with aberrant conduction this is demonstrated when the broader complexes are seen terminating a relatively short cycle that follows a relatively long one. The QRS terminating the shorter cycle is conducted 'more aberrantly' because it falls in the refractory period. The aberrancy is usually of a RBBB pattern. <cite>Gouaux</cite> | ||
'''1947''' Claude Beck, a pioneering cardiovascular surgeon in Cleveland, successfully defibrillates a human heart during cardiac surgery. The patient is a 14 year old boy - 6 other patients had failed to respond to the defibrillator. His prototype defibrillator followed experiments on defibrillation in animals performed by Carl J. Wiggers, Professor of Physiology at the Western Reserve University. Beck CS, Pritchard WH, Feil SA: Ventricular fibrillation of long duration abolished by electric shock. JAMA 1947; 135: 985-989. | '''1947''' Claude Beck, a pioneering cardiovascular surgeon in Cleveland, successfully defibrillates a human heart during cardiac surgery. The patient is a 14 year old boy - 6 other patients had failed to respond to the defibrillator. His prototype defibrillator followed experiments on defibrillation in animals performed by Carl J. Wiggers, Professor of Physiology at the Western Reserve University. Beck CS, Pritchard WH, Feil SA: Ventricular fibrillation of long duration abolished by electric shock. JAMA 1947; 135: 985-989. | ||
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Rune Elmqvist, Swedish engineer who had trained as a doctor but never practiced, introduces the first ink jet printer for the transcription of analog physiological signals. He demonstrates its use in the recording of ECGs at the First International Congress of Cardiology in Paris in 1950. The machine (the mingograph) was developed by him at the company that later became Siemens. (Luderitz, 2002) | Rune Elmqvist, Swedish engineer who had trained as a doctor but never practiced, introduces the first ink jet printer for the transcription of analog physiological signals. He demonstrates its use in the recording of ECGs at the First International Congress of Cardiology in Paris in 1950. The machine (the mingograph) was developed by him at the company that later became Siemens. (Luderitz, 2002) | ||
'''1949''' Montana physician Norman Jeff Holter develops a 75 pound backpack that can record the ECG of the wearer and transmit the signal. His system, the Holter Monitor, is later greatly reduced in size, combined with tape / digital recording and used to record ambulatory ECGs. Holter | '''1949''' Montana physician Norman Jeff Holter develops a 75 pound backpack that can record the ECG of the wearer and transmit the signal. His system, the Holter Monitor, is later greatly reduced in size, combined with tape / digital recording and used to record ambulatory ECGs. <cite>Holter</cite> | ||
'''1949''' Sokolow and Lyon propose diagnostic criteria for left ventricular hypertrophy i.e. LVH is present if the sum of the size of the S wave in V1 plus the R wave in V6 exceeds 35 mm. Sokolow M, Lyon TP. The ventricular complex in left ventricular hypertrophy as obtained by unipolar precordial and limb leads. Am Heart J 1949;37:161 | '''1949''' Sokolow and Lyon propose diagnostic criteria for left ventricular hypertrophy i.e. LVH is present if the sum of the size of the S wave in V1 plus the R wave in V6 exceeds 35 mm. Sokolow M, Lyon TP. The ventricular complex in left ventricular hypertrophy as obtained by unipolar precordial and limb leads. Am Heart J 1949;37:161 | ||
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'''1958''' Professor Ake Senning, of Sweden, places the first implantable cardiac pacemaker designed by Rune Elmqvist into a 43-year-old patient with complete heart block and syncope (Arne Larsson). | '''1958''' Professor Ake Senning, of Sweden, places the first implantable cardiac pacemaker designed by Rune Elmqvist into a 43-year-old patient with complete heart block and syncope (Arne Larsson). | ||
'''1959''' Myron Prinzmetal describes a variant form of angina in which the ST segment is elevated rather than depressed. Prinzmetal | '''1959''' Myron Prinzmetal describes a variant form of angina in which the ST segment is elevated rather than depressed. <cite>Prinzmetal</cite> | ||
'''1960''' Smirk and Palmer highlight the risk of sudden death from ventricular fibrillation particularly when ventricular premature beats occur at the same time as the T wave. The 'R on T' phenomenon. Smirk FH, Palmer DG. A myocardial syndrome, with particular reference to the occurrence of sudden death and of premature systoles interrupting antecedent T waves. Am J Cardiol 1960;6:620. | '''1960''' Smirk and Palmer highlight the risk of sudden death from ventricular fibrillation particularly when ventricular premature beats occur at the same time as the T wave. The 'R on T' phenomenon. Smirk FH, Palmer DG. A myocardial syndrome, with particular reference to the occurrence of sudden death and of premature systoles interrupting antecedent T waves. Am J Cardiol 1960;6:620. | ||
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#Gussak pmid=11173780 | #Gussak pmid=11173780 | ||
#Clemmensen pmid=16226101 | #Clemmensen pmid=16226101 | ||
#Ader Ader C. ''Sur un nouvel appareil enregistreur pour cables sous-marins.'' C R Acad Sci (Paris) 1897;124:1440-1442 | |||
#Prevost Prevost JL, Batelli F: ''Sur quelques effets des descharges electriques sur le coeur des mammiferes.'' Acad. Sci. Paris, FR.: 1899; 129:1267-1268. | |||
#Holter Holter NJ, Generelli JA. ''Remote recording of physiologic data by radio.'' Rocky Mountain Med J. 1949;747-751. | |||
#Ernstine Ernstine AC, Levine SA. ''A comparison of records taken with the Einthoven string galvanomter and the amplifier-type electrocardiograph.'' Am Heart J 1928;4:725-731 | |||
#Dubois Du Bois-Reymond, E. ''Untersuchungen über thierische Elektricität''. Reimer, Berlin: 1848. | #Dubois Du Bois-Reymond, E. ''Untersuchungen über thierische Elektricität''. Reimer, Berlin: 1848. | ||
#Waller2 Waller AD. ''Introductory Address on The Electromotive Properties of the Human Heart''. Brit. Med J, 1888;2:751-754 | #Waller2 Waller AD. ''Introductory Address on The Electromotive Properties of the Human Heart''. Brit. Med J, 1888;2:751-754 | ||
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#Hoffa Hoffa M, Ludwig C. 1850. ''Einige neue versuche uber herzbewegung''. Zeitschrift Rationelle Medizin, 9: 107-144 | #Hoffa Hoffa M, Ludwig C. 1850. ''Einige neue versuche uber herzbewegung''. Zeitschrift Rationelle Medizin, 9: 107-144 | ||
#Waller Waller AD. ''A demonstration on man of electromotive changes accompanying the heart's beat.'' J Physiol (London) 1887;8:229-234 | #Waller Waller AD. ''A demonstration on man of electromotive changes accompanying the heart's beat.'' J Physiol (London) 1887;8:229-234 | ||
#Wood Wood FC, Wolferth CC, Livezey MM. ''Angina pectoris.'' Archives Internal Medicine 1931;47:339 | |||
#Pardee Pardee HEB. ''An electrocardiographic sign of coronary artery obstruction.'' Arch Int Med 1920;26:244-257 | |||
#Sanders Sanders, A.O. ''Coronary thrombosis with complete heart block and relative ventricular tachycardia: a case report,'' American Heart Journal 1930;6:820-823. | |||
#Einthoven Einthoven W. ''Le telecardiogramme''. Arch Int de Physiol 1906;4:132-164 | #Einthoven Einthoven W. ''Le telecardiogramme''. Arch Int de Physiol 1906;4:132-164 | ||
# | #Einthoven Einthoven W. ''Über die Form des menschlichen Electrocardiogramms''. Pfügers Archiv march 1895, p 101-123 | ||
#Marey Marey EJ. ''Des variations electriques des muscles et du couer en particulier etudies au moyen de l'electrometre de M Lippman.'' Compres Rendus Hebdomadaires des Seances de l'Acadamie des sciences 1876;82:975-977 | #Einthoven3 Einthoven W. ''Un nouveau galvanometre.'' Arch Neerl Sc Ex Nat 1901;6:625-633 | ||
#Prinzmetal pmid=14434946 | |||
#Marey Marey EJ. ''Des variations electriques des muscles et du couer en particulier etudies au moyen de l'electrometre de M | |||
Lippman.'' Compres Rendus Hebdomadaires des Seances de l'Acadamie des sciences 1876;82:975-977 | |||
#Gouaux Gouaux JL, Ashman R. ''Auricular fibrillation with aberration simulating ventricular paroxysmal tachycardia.'' Am Heart J 1947;34:366-73. | |||
#Marquez pmid=12177632 | #Marquez pmid=12177632 | ||
#Hurst pmid=9799216 | #Hurst pmid=9799216 | ||