The The 1010 Greatest Greatest Advances in Cardiology Advances in Cardiology

in the in the 2020thth century century

Dr. Antoinette CilliersDr. Antoinette CilliersDepartment of Paediatrics and Child Department of Paediatrics and Child HealthHealth

1. Electrocardiogram1. Electrocardiogram

ECGECG

The ECG measures the electrical activity of the heart.

This includes: • the rate and regularity of beats• the size and position of the chambers • any damage to the heart and • effects of drugs or devices to regulate the heart.

Each heartbeat in a normally functioning heart exhibits a similar characteristic pattern consisting of five waves referred to as P, Q, R, S and T.

HistoryHistory

William Einthoven,William Einthoven, observed Waller demonstrating observed Waller demonstrating the use of the capillary electrometer to record an the use of the capillary electrometer to record an “electrograph” of the heart. “electrograph” of the heart.

In In 18951895, he was able to detect recognizable waves, , he was able to detect recognizable waves, which he labelled “P, Q, R, S, and T.” Formulated the which he labelled “P, Q, R, S, and T.” Formulated the concept of “Einthoven's triangle” by mathematically concept of “Einthoven's triangle” by mathematically relating the 3 leads relating the 3 leads (Lead III = Lead II – Lead I).(Lead III = Lead II – Lead I).

He described bigeminy, complete heart block, He described bigeminy, complete heart block, “P mitrale,” right and left and ventricular hypertrophy, “P mitrale,” right and left and ventricular hypertrophy, atrial fibrillation and flutter, the U wave, and examples atrial fibrillation and flutter, the U wave, and examples of various heart diseases of various heart diseases

The “father of electrocardiography” was honoured with The “father of electrocardiography” was honoured with the Nobel Prize in Medicine in the Nobel Prize in Medicine in 19241924. .

• 18561856 - - von Koelliker and Müller first to discover that the von Koelliker and Müller first to discover that the heart generated electricity. heart generated electricity. • 18871887 - Waller published first report of a recording of - Waller published first report of a recording of cardiac electricity on the body's surface; called the cardiac electricity on the body's surface; called the recording a “cardiograph.” recording a “cardiograph.”

2. Echocardiography2. Echocardiography

EchocardiogramEchocardiogram

An echocardiogram is an An echocardiogram is an ultrasound scan of the heart. ultrasound scan of the heart.

Jelly is applied to the chest wall Jelly is applied to the chest wall and an ultrasound probe is and an ultrasound probe is placed on the chest wall to placed on the chest wall to build up a picture of the build up a picture of the function and structure of the function and structure of the heart. heart.

It can measure the It can measure the effectiveness of the pumping effectiveness of the pumping action of the heart and how action of the heart and how efficiently the heart valves are efficiently the heart valves are working.working.

This investigation is done as an This investigation is done as an out patient appointment.out patient appointment.

History of History of EchocardigraphyEchocardigraphy 18801880 - Pierre and Jacques Curie discovered piezoelectricity. - Pierre and Jacques Curie discovered piezoelectricity.

During During World War IIWorld War II, the field of sonar ultrasonography , the field of sonar ultrasonography advanced rapidly because of its use for detecting advanced rapidly because of its use for detecting submarines. submarines.

The pioneers of echocardiography were The pioneers of echocardiography were Inge EdlerInge Edler, a , a Swedish cardiologist and Swedish cardiologist and Hellmuth HertzHellmuth Hertz, a Swedish , a Swedish physicist.physicist.

Edler and Hertz borrowed a sonar device from a local Edler and Hertz borrowed a sonar device from a local shipyard, improved it, and recorded cardiac echoes from shipyard, improved it, and recorded cardiac echoes from Hertz's own heart.Hertz's own heart.

They first reported the continuous recording of movements They first reported the continuous recording of movements of the heart walls in of the heart walls in 19541954 and described the use of the and described the use of the ultrasonic cardiogram for mitral valve diseases in ultrasonic cardiogram for mitral valve diseases in 19561956. .

EchocardiographyEchocardiography

• With the development of With the development of Doppler echocardiography in Doppler echocardiography in the the 1960s1960s, the ink-jet printer , the ink-jet printer (another invention by Hertz) (another invention by Hertz) was useful in the development was useful in the development of the colour Doppler of the colour Doppler technique. technique.

• In In 19771977, Edler and Hertz , Edler and Hertz were joint recipients of the were joint recipients of the Lasker Prize, which is the Lasker Prize, which is the American equivalent of the American equivalent of the Nobel Prize in Medicine.Nobel Prize in Medicine.

3. Cardiac 3. Cardiac Catheterization and Catheterization and Coronary Angiography Coronary Angiography

AngiogramAngiogram

This is carried out by injecting a dye which can This is carried out by injecting a dye which can be seen on X-ray into the coronary arteries via be seen on X-ray into the coronary arteries via a catheter which is fed into the femoral artery a catheter which is fed into the femoral artery (groin) or brachial artery (arm). (groin) or brachial artery (arm).

The area is first treated with local anaesthetic. The area is first treated with local anaesthetic. A series of x-rays are taken to determine the A series of x-rays are taken to determine the

percentage of narrowing of the three branches percentage of narrowing of the three branches of the coronary artery.of the coronary artery.

This investigation is usually done as a day This investigation is usually done as a day case, but occasionally an overnight stay in case, but occasionally an overnight stay in hospital is necessary.hospital is necessary.

Cardiac Catheterization Cardiac Catheterization and Coronary and Coronary AngiographyAngiography 18441844 - Claude Bernard, a noted French research physiologist, - Claude Bernard, a noted French research physiologist,

used catheters to record intracardiac pressures in animals and used catheters to record intracardiac pressures in animals and coined the term “cardiac catheterization.” coined the term “cardiac catheterization.”

With the discovery of x-rays in With the discovery of x-rays in 18951895 by Wilhelm Roentgen, a by Wilhelm Roentgen, a new approach to the study of cardiac anatomy became new approach to the study of cardiac anatomy became possible.possible.

19071907 - Two German physicians, Friedrich Jamin and Hermann - Two German physicians, Friedrich Jamin and Hermann Merkel, published the 1st roentgenographic atlas of the human Merkel, published the 1st roentgenographic atlas of the human coronary arteries in. Study of 29 hearts in which the coronary coronary arteries in. Study of 29 hearts in which the coronary arteries were injected with a suspension of red lead in gelatin. arteries were injected with a suspension of red lead in gelatin.

1929 -1929 - a young surgical resident, Werner Forssmann, a young surgical resident, Werner Forssmann, performed the 1st documented human cardiac catheterization performed the 1st documented human cardiac catheterization on himself in Germany. He anaesthetized his left elbow, on himself in Germany. He anaesthetized his left elbow, inserted a catheter into his antecubital vein, and confirmed inserted a catheter into his antecubital vein, and confirmed the position of the catheter tip in the right atrium by use of the position of the catheter tip in the right atrium by use of radiography. His goal was to find a safe and effective way to radiography. His goal was to find a safe and effective way to inject drugs for cardiac resuscitation. inject drugs for cardiac resuscitation.

Cardiac Catheterization Cardiac Catheterization and Coronary and Coronary AngiographyAngiography Forssmann next injected contrast material through a Forssmann next injected contrast material through a

catheter placed in the right atrium. His contributions, along catheter placed in the right atrium. His contributions, along with the development of nontoxic contrast media and the with the development of nontoxic contrast media and the steady advances in radiological techniques, prepared the steady advances in radiological techniques, prepared the way for the development of coronary angiography. way for the development of coronary angiography.

19411941 - Cournand and Richards used cardiac catheter as a - Cournand and Richards used cardiac catheter as a diagnostic tool for the 1st time, applying catheterization diagnostic tool for the 1st time, applying catheterization techniques to measure right-heart pressures and cardiac techniques to measure right-heart pressures and cardiac output. output.

For their landmark work, they shared a Nobel Prize in For their landmark work, they shared a Nobel Prize in Medicine with Forssmann in Medicine with Forssmann in 19561956..

19581958 - Mason Sones performed selective coronary - Mason Sones performed selective coronary arteriography in a series of more than 1,000 patients. This arteriography in a series of more than 1,000 patients. This development initiated a period of rapid growth in coronary development initiated a period of rapid growth in coronary arteriography during the arteriography during the mid 1960smid 1960s..

Melvin Judkins, a radiologist who had studied coronary Melvin Judkins, a radiologist who had studied coronary angiography with Sones, created his own system of angiography with Sones, created his own system of coronary imaging in coronary imaging in 19671967, introducing a series of , introducing a series of specialized catheters and perfecting the transfemoral specialized catheters and perfecting the transfemoral approach.approach.

4. Framingham heart 4. Framingham heart studystudy

Framingham studyFramingham study

The Framingham Study is one of the most impressive medical The Framingham Study is one of the most impressive medical works in the 20th century. During the 1st half of the century, works in the 20th century. During the 1st half of the century, there was a steady increase in deaths attributed to heart disease. there was a steady increase in deaths attributed to heart disease. However, the causes of coronary heart disease were speculative.However, the causes of coronary heart disease were speculative.

With support from the newly created National Heart Institute (now With support from the newly created National Heart Institute (now National Heart, Lung, and Blood Institute [NHLBI]), the 1st National Heart, Lung, and Blood Institute [NHLBI]), the 1st collection of information from a community cohort was gathered. collection of information from a community cohort was gathered.

Between Between 1948 and 19511948 and 1951, 1980 men and 2421 women were , 1980 men and 2421 women were enrolled in an observational study in Framingham, Massachusetts.enrolled in an observational study in Framingham, Massachusetts.

The 1st report of this long-term study, “Factors of risk in the The 1st report of this long-term study, “Factors of risk in the development of coronary heart disease - six-year follow-up development of coronary heart disease - six-year follow-up experience”; was published in experience”; was published in 19611961. .

The study showed that high blood pressure, smoking, and high The study showed that high blood pressure, smoking, and high cholesterol levels were major factors in heart disease. From this cholesterol levels were major factors in heart disease. From this report, the concept of risk factors emerged.report, the concept of risk factors emerged.

Framingham studyFramingham study

The Framingham Study provided information crucial to the The Framingham Study provided information crucial to the recognition and management of atherosclerosis, its causes, and recognition and management of atherosclerosis, its causes, and its complications. its complications.

Fifty years' worth of data collected from the residents of Fifty years' worth of data collected from the residents of Framingham has Framingham has – produced over 1,000 scientific papers; produced over 1,000 scientific papers; – introduced the concepts of biologic, environmental, and introduced the concepts of biologic, environmental, and

behavioral risk factors;behavioral risk factors;– identified major risk factors associated with heart disease, identified major risk factors associated with heart disease,

stroke, and other diseases; stroke, and other diseases; – created a revolution in preventive medicine; and created a revolution in preventive medicine; and – forever changed the ways in which the medical community forever changed the ways in which the medical community

and the general population view the genesis of disease. and the general population view the genesis of disease.

First cardiovascular study that included women participants. First cardiovascular study that included women participants. Has served as the model for many other longitudinal cohort Has served as the model for many other longitudinal cohort

studies. studies.

5. “Lipid Hypotheses” 5. “Lipid Hypotheses” and Atherosclerosis and Atherosclerosis

Lipids and Lipids and atherosclerosis atherosclerosis During the During the 19th century-19th century- arteriosclerosis well recognized, but arteriosclerosis well recognized, but

its etiologic and pathologic significance not established.its etiologic and pathologic significance not established. Hypotheses – e.g. disturbed arterial metabolism, Hypotheses – e.g. disturbed arterial metabolism,

adherent blood clots that gradually changed into adherent blood clots that gradually changed into arteriosclerotic plaques.arteriosclerotic plaques.

19041904 - Felix Marchand introduced the term atherosclerosis; - Felix Marchand introduced the term atherosclerosis; suggested atherosclerosis was responsible for nearly all suggested atherosclerosis was responsible for nearly all obstructive processes in arteries.obstructive processes in arteries.

19081908 – a Russian, Ignatowski, observed possible relation – a Russian, Ignatowski, observed possible relation between cholesterol-rich foods and experimental between cholesterol-rich foods and experimental atherosclerosis. atherosclerosis.

19101910 - Adolf Windaus showed that atheromatous lesions - Adolf Windaus showed that atheromatous lesions contained 6 times as much free cholesterol as a normal contained 6 times as much free cholesterol as a normal arterial wall and 20 times more esterified cholesterol. arterial wall and 20 times more esterified cholesterol.

19131913- Using cholesterol-fed rabbits to produce experimental - Using cholesterol-fed rabbits to produce experimental atherosclerosis, Nikolai Anichkov demonstrated that atherosclerosis, Nikolai Anichkov demonstrated that cholesterol alone that caused these atherosclerotic changes in cholesterol alone that caused these atherosclerotic changes in the rabbit intima. Found early lesions, such as fatty streaks, as the rabbit intima. Found early lesions, such as fatty streaks, as well as advanced lesions; and discovered that the amount of well as advanced lesions; and discovered that the amount of cholesterol uptake was directly proportional to the degree of cholesterol uptake was directly proportional to the degree of atherosclerosis severity. atherosclerosis severity.

Lipids and Lipids and atherosclerosisatherosclerosis 19501950 -Gofman identified the low-density lipoprotein (LDL) -Gofman identified the low-density lipoprotein (LDL)

cholesterol and high-density lipoprotein (HDL) cholesterol cholesterol and high-density lipoprotein (HDL) cholesterol using the ultracentrifuge technique. Found that 101 of 104 using the ultracentrifuge technique. Found that 101 of 104 men with myocardial infarction had elevated LDL moleculesmen with myocardial infarction had elevated LDL molecules— similar to their cholesterol-fed atherosclerotic rabbits. — similar to their cholesterol-fed atherosclerotic rabbits. Gofman's group observed an inverse relationship between Gofman's group observed an inverse relationship between HDLs and risk of coronary artery disease. HDLs and risk of coronary artery disease.

19521952 - Kinsell - ingestion of plant foods and avoidance of - Kinsell - ingestion of plant foods and avoidance of animal fats decreased the blood level of cholesterol. animal fats decreased the blood level of cholesterol.

Framingham Study - showed that the risk of developing Framingham Study - showed that the risk of developing clinically significant coronary artery disease was a clinically significant coronary artery disease was a continuous curvilinear function of blood cholesterol levels.continuous curvilinear function of blood cholesterol levels.

During the During the 1950s and 1960s-1950s and 1960s- many cholesterol-lowering many cholesterol-lowering agents were introduced into clinical use, including nicotinic agents were introduced into clinical use, including nicotinic acid, cholestyramine, clofibrate, and plant sterols.acid, cholestyramine, clofibrate, and plant sterols.

19611961- the American Heart Association began encouraging - the American Heart Association began encouraging people to follow a “prudent diet”people to follow a “prudent diet”

Lipids and Lipids and atherosclerosisatherosclerosis 19641964 - Bloch and Lynen received the Nobel Prize in - Bloch and Lynen received the Nobel Prize in

Medicine for their work on the metabolism of cholesterol Medicine for their work on the metabolism of cholesterol and fatty acids.and fatty acids.

1970s 1970s - Brown and Goldstein identified the LDL receptor - Brown and Goldstein identified the LDL receptor and the LDL pathway and shared the 1985 Nobel Prize in and the LDL pathway and shared the 1985 Nobel Prize in Medicine.Medicine.

Major breakthrough in the pharmacologic management of Major breakthrough in the pharmacologic management of hypercholesterolemia was the discovery of the statins (3-hypercholesterolemia was the discovery of the statins (3-hydroxy-3-methylglutaryl coenzyme A reductase hydroxy-3-methylglutaryl coenzyme A reductase inhibitors). Akira Endo in Japan discovered the earliest inhibitors). Akira Endo in Japan discovered the earliest statin, compactin, in statin, compactin, in 19761976. .

19851985 - the NHLBI established the National Cholesterol - the NHLBI established the National Cholesterol Education Program to educate both physicians and patients Education Program to educate both physicians and patients about the importance of treating hypercholesterolemia, and about the importance of treating hypercholesterolemia, and the 1st guidelines were published in the 1st guidelines were published in 19881988..

6. Coronary Care Units 6. Coronary Care Units

Coronary care unitsCoronary care units

Early Early 1960s1960s - technique of closed-chest cardiopulmonary - technique of closed-chest cardiopulmonary resuscitation and continuous telemetry monitoring with an alarm resuscitation and continuous telemetry monitoring with an alarm system laid the groundwork for coronary care units (CCUs)—system laid the groundwork for coronary care units (CCUs)—specialized intensive care units for patients with acute myocardial specialized intensive care units for patients with acute myocardial infarctions (MIs).infarctions (MIs).

These developments were combined with 2 simple strategies:These developments were combined with 2 simple strategies:– 1) the clustering of patients with MIs on a single hospital unit, where 1) the clustering of patients with MIs on a single hospital unit, where

necessary equipment and drugs were readily available and where necessary equipment and drugs were readily available and where trained personnel could be in continuous attendance; and trained personnel could be in continuous attendance; and

– 2) the training of specialized nurses to recognize and treat 2) the training of specialized nurses to recognize and treat arrhythmias rapidly in the absence of a physician. arrhythmias rapidly in the absence of a physician.

Major objective was to reduce the number of deaths caused by Major objective was to reduce the number of deaths caused by arrhythmias.arrhythmias.

However, no measures were available to manage overwhelming However, no measures were available to manage overwhelming shock or refractory pulmonary oedema resulting from pump shock or refractory pulmonary oedema resulting from pump failure. failure.

Coronary care unitsCoronary care units

Desmond Julian presented the 1st description of the Desmond Julian presented the 1st description of the CCU to the British Thoracic Society in CCU to the British Thoracic Society in 19611961. .

19621962- Bauer and White started a CCU in a Sydney - Bauer and White started a CCU in a Sydney hospital. hospital.

19671967 - Killip and Kimball published their experience - Killip and Kimball published their experience consisting of 250 patients with MIs who had been consisting of 250 patients with MIs who had been treated in the CCU. Compared with other patients who treated in the CCU. Compared with other patients who had experienced MIs, those treated in the CCU had had experienced MIs, those treated in the CCU had better survival rates in the absence of cardiogenic better survival rates in the absence of cardiogenic shock.shock.

From experience in early CCUs, it soon became From experience in early CCUs, it soon became apparent that arrhythmias were much more common apparent that arrhythmias were much more common than had previously been suspected. Ventricular than had previously been suspected. Ventricular extrasystoles were found to be almost universal and extrasystoles were found to be almost universal and generated a lot of interest as “warning” arrhythmias. generated a lot of interest as “warning” arrhythmias.

Coronary care unitsCoronary care units

Bernard Lown and colleagues reported that they found no Bernard Lown and colleagues reported that they found no occurrence of ventricular fibrillation when patients who occurrence of ventricular fibrillation when patients who experienced warning arrhythmias were treated with experienced warning arrhythmias were treated with lidocaine. lidocaine.

19671967 - The development of CCUs coincided with a rapid - The development of CCUs coincided with a rapid expansion in the use of transvenous pacing, which was expansion in the use of transvenous pacing, which was performed in 35% of patients with MIs in one centre in New performed in 35% of patients with MIs in one centre in New YorkYork

Early success in CCUs with resuscitation and with the Early success in CCUs with resuscitation and with the detection and treatment of arrhythmias focused detection and treatment of arrhythmias focused researchers' attention on left ventricular failure and researchers' attention on left ventricular failure and cardiogenic shock. cardiogenic shock.

The Myocardial Infarction Research Units were created in The Myocardial Infarction Research Units were created in the United States by the NHLBI, and a large program of the United States by the NHLBI, and a large program of research was initiated for the investigation of the research was initiated for the investigation of the hemodynamic effects of myocardial infarction. hemodynamic effects of myocardial infarction.

The Swan-Ganz flow-guided catheter was introduced, and The Swan-Ganz flow-guided catheter was introduced, and its use for invasive monitoring of cardiac hemodynamics its use for invasive monitoring of cardiac hemodynamics became routine in some centres. became routine in some centres.

7. Thrombolytic 7. Thrombolytic Therapy Therapy

Thrombolytic TherapyThrombolytic Therapy 19331933 - Tillet and Garner discovered that Group A β-haemolytic - Tillet and Garner discovered that Group A β-haemolytic

streptococci produced a fibrinolytic substance (streptococcal streptococci produced a fibrinolytic substance (streptococcal fibrinolysin). fibrinolysin).

19411941 - Milstone suggested that a plasma factor, which he called - Milstone suggested that a plasma factor, which he called a “plasma lysing factor,” was necessary for streptococcal-a “plasma lysing factor,” was necessary for streptococcal-mediated fibrinolysis. mediated fibrinolysis.

19451945 - Christensen, a microbiologist, was able to describe the - Christensen, a microbiologist, was able to describe the entire mechanism of streptococcal fibrinolysis. Showed human entire mechanism of streptococcal fibrinolysis. Showed human plasma contained the precursor of an enzyme system, which he plasma contained the precursor of an enzyme system, which he called plasminogen, and that the streptococcal fibrinolysin, called plasminogen, and that the streptococcal fibrinolysin, which he named streptokinase, was an activator that could which he named streptokinase, was an activator that could convert plasminogen to the proteolytic and fibrinolytic enzyme convert plasminogen to the proteolytic and fibrinolytic enzyme plasmin. plasmin.

19471947- Christensen made available to Tillet a crudely purified - Christensen made available to Tillet a crudely purified preparation of streptokinase. Animal experiments with preparation of streptokinase. Animal experiments with streptokinase in order to determine its efficacy in the treatment streptokinase in order to determine its efficacy in the treatment of acute coronary thrombosis. of acute coronary thrombosis.

19521952 - Tillet and Johnson reported lysis of experimental thrombi - Tillet and Johnson reported lysis of experimental thrombi in rabbits' ears with intravenous streptokinase administered in rabbits' ears with intravenous streptokinase administered through a peripheral vein. through a peripheral vein.

Thrombolytic TherapyThrombolytic Therapy

19571957 - Sherry reported a rational approach to - Sherry reported a rational approach to thrombolysis using a loading dose and a sustained thrombolysis using a loading dose and a sustained infusion of streptokinase sufficient to increase the infusion of streptokinase sufficient to increase the clot-dissolving activity of plasma by several hundred-clot-dissolving activity of plasma by several hundred-fold. fold.

19581958 - 1st study of intravenously administered - 1st study of intravenously administered streptokinase performed in patients who had MIs.streptokinase performed in patients who had MIs.

DeWood provided angiographic evidence of a very DeWood provided angiographic evidence of a very high incidence of total occlusion of infarct-related high incidence of total occlusion of infarct-related arteries during the early period of infarction, and arteries during the early period of infarction, and

Rentrop demonstrated rapid recanalization after local Rentrop demonstrated rapid recanalization after local administration of streptokinase directly into an infarct-administration of streptokinase directly into an infarct-related artery. related artery.

Thereafter, the Netherlands trial, the Western Thereafter, the Netherlands trial, the Western Washington trials, and ISIS-2 demonstrated both Washington trials, and ISIS-2 demonstrated both short- and long-term benefits of thrombolytic therapy. short- and long-term benefits of thrombolytic therapy.

8. Open-Heart Surgery 8. Open-Heart Surgery

Open-Heart SurgeryOpen-Heart Surgery

18491849- Wilfred Bigelow and his team performed open-- Wilfred Bigelow and his team performed open-heart procedures in animals with the use of heart procedures in animals with the use of hypothermia hypothermia

19531953 - John Lewis performed the 1st successful closure - John Lewis performed the 1st successful closure of an atrial septal defect in a 5-year-old girl, using the of an atrial septal defect in a 5-year-old girl, using the open-heart hypothermic technique that Bigelow's group open-heart hypothermic technique that Bigelow's group had developed. had developed.

19531953 - The heart-lung machine, which offered additional - The heart-lung machine, which offered additional protection to vital organs, used by John Gibbon during protection to vital organs, used by John Gibbon during the repair of an atrial septal defect.the repair of an atrial septal defect.

1956 -1956 - Walton Lillehei and his team corrected pure Walton Lillehei and his team corrected pure mitral regurgitation with suture plication of the mitral regurgitation with suture plication of the commissures under direct vision. commissures under direct vision.

After that time, many surgeons around the world After that time, many surgeons around the world became involved in direct vision repair, and prosthetic became involved in direct vision repair, and prosthetic valves were introduced for cardiac valve replacement.valves were introduced for cardiac valve replacement.

Open-Heart SurgeryOpen-Heart Surgery

19351935 - Claude Beck published his classic paper, “The - Claude Beck published his classic paper, “The development of a new blood supply to the heart by operation,” development of a new blood supply to the heart by operation,” which described his technique of grafting a flap of the pectoralis which described his technique of grafting a flap of the pectoralis muscle over the exposed epicardium to create a new blood muscle over the exposed epicardium to create a new blood supply. supply.

19461946 - Vineberg used the internal mammary artery to provide a - Vineberg used the internal mammary artery to provide a new source of blood to the myocardium. Technique became very new source of blood to the myocardium. Technique became very popular; about 5,000 such operations performed between 1950 popular; about 5,000 such operations performed between 1950 and 1970. and 1970.

19641964 - Vasilii Kolessov, a Russian cardiac surgeon, performed - Vasilii Kolessov, a Russian cardiac surgeon, performed the 1st internal mammary artery–coronary artery anastomosis. the 1st internal mammary artery–coronary artery anastomosis.

19671967 - René Favaloro achieved a physiologic approach in the - René Favaloro achieved a physiologic approach in the surgical management of coronary artery disease—the bypass surgical management of coronary artery disease—the bypass grafting procedure. Used a saphenous vein autograft to replace grafting procedure. Used a saphenous vein autograft to replace a stenotic segment of the right coronary artery. Began to use a stenotic segment of the right coronary artery. Began to use the saphenous vein as a bypassing channel. Soon Dudley the saphenous vein as a bypassing channel. Soon Dudley Johnson extended the bypass procedure to include the left Johnson extended the bypass procedure to include the left coronary arterial systems. coronary arterial systems.

19681968 – Use of the internal mammary artery instead of the – Use of the internal mammary artery instead of the saphenous vein for bypass grafting. saphenous vein for bypass grafting.

TodayToday, coronary artery bypass grafting has become one of the , coronary artery bypass grafting has become one of the most common operations and is performed all over the world.most common operations and is performed all over the world.

9. Automatic 9. Automatic Implantable Cardiac Implantable Cardiac Defibrillators Defibrillators

Automatic Implantable Automatic Implantable Cardiac DefibrillatorsCardiac Defibrillators 17751775 - 1st successful attempt at electrical defibrillation. - 1st successful attempt at electrical defibrillation.

Peter Abildgaard, a Danish veterinarian, evaluated the Peter Abildgaard, a Danish veterinarian, evaluated the effects of electrical shock and countershock on chickens. effects of electrical shock and countershock on chickens.

18991899 - Prevost and Batelli noted that if shock was - Prevost and Batelli noted that if shock was applied within seconds of the onset of fibrillation, the applied within seconds of the onset of fibrillation, the result was defibrillation, which successfully restored result was defibrillation, which successfully restored sinus rhythm. sinus rhythm.

19321932 - Original concept of the artificial pacemaker is - Original concept of the artificial pacemaker is attributed to Albert Hymanattributed to Albert Hyman

19471947 - Beck first to apply electrical defibrillation to a - Beck first to apply electrical defibrillation to a human heart in the operating room.human heart in the operating room.

19501950- Bigelow, Callaghan and Hopps developed a - Bigelow, Callaghan and Hopps developed a technique of transvenous pacing.technique of transvenous pacing.

Smith and Stone Ltd. built the 1st commercial Smith and Stone Ltd. built the 1st commercial pacemaker to their design. pacemaker to their design.

19561956 - Zoll and co-workers performed the 1st successful - Zoll and co-workers performed the 1st successful external defibrillation in a human subject.external defibrillation in a human subject.

Automatic Implantable Automatic Implantable Cardiac DefibrillatorsCardiac Defibrillators

19581958 - In Sweden, Senning and Elmqvist designed a - In Sweden, Senning and Elmqvist designed a miniature pulse generator, which was implanted after a miniature pulse generator, which was implanted after a thoracotomy. thoracotomy.

Greatbatch, in the United States, devised an implantable Greatbatch, in the United States, devised an implantable pacemaker powered by a mercury-zinc battery. pacemaker powered by a mercury-zinc battery.

19621962 - The early devices were all asynchronous; the 1st - The early devices were all asynchronous; the 1st atrioventricular (AV) synchronous pacemaker, which atrioventricular (AV) synchronous pacemaker, which simulated a true physiologic state, was implanted. simulated a true physiologic state, was implanted.

These achievements and the expanding knowledge of clinical These achievements and the expanding knowledge of clinical electrophysiology led to the invention of the automatic electrophysiology led to the invention of the automatic implantable cardiac defibrillator (AICD). implantable cardiac defibrillator (AICD).

This device was meant to abort ventricular fibrillation at its This device was meant to abort ventricular fibrillation at its onset, thus averting the inevitably fatal outcome.onset, thus averting the inevitably fatal outcome.

Automatic Implantable Automatic Implantable Cardiac DefibrillatorsCardiac Defibrillators Mirowski, Mower, and Staewen at Sinai Hospital of Baltimore Mirowski, Mower, and Staewen at Sinai Hospital of Baltimore

collaborated on the AICD in collaborated on the AICD in 19691969. The concept of the AICD . The concept of the AICD generated a lot of criticism, but the Baltimore group generated a lot of criticism, but the Baltimore group continued to pursue their research. continued to pursue their research.

Heilman joined that group in Heilman joined that group in 19721972. He helped make sensing . He helped make sensing circuits that could identify ventricular fibrillation on the basis circuits that could identify ventricular fibrillation on the basis of a mathematical formula called the probability density of a mathematical formula called the probability density function. function.

19801980 - after extensive animal research, Mirowski's team - after extensive animal research, Mirowski's team successfully treated their 1st human patient with an AICD. In successfully treated their 1st human patient with an AICD. In their first 50 patients, the mortality rate was less than 10%. their first 50 patients, the mortality rate was less than 10%.

Soon the AICD became the treatment of choice for patients Soon the AICD became the treatment of choice for patients with life-threatening ventricular tachyarrhythmias by with life-threatening ventricular tachyarrhythmias by consistently outperforming the best medications available consistently outperforming the best medications available for these patients.for these patients.

10. Coronary 10. Coronary Angioplasty Angioplasty

Coronary AngioplastyCoronary Angioplasty

1964 -1964 - Charles Dotter and Melvin Judkins described a Charles Dotter and Melvin Judkins described a new technique for relieving stenosis of the iliofemoral new technique for relieving stenosis of the iliofemoral arteries with rigid dilators. arteries with rigid dilators.

The procedure was largely ignored in the US because The procedure was largely ignored in the US because of technical difficulties and complications but used to of technical difficulties and complications but used to treat large numbers of patients in Europe.treat large numbers of patients in Europe.

1974 1974 - In Zurich, Andreas Gruentzig substituted a - In Zurich, Andreas Gruentzig substituted a balloon-tipped catheter for the rigid dilator and balloon-tipped catheter for the rigid dilator and performed the 1st peripheral balloon angioplasty in a performed the 1st peripheral balloon angioplasty in a human being. human being.

After achieving success with coronary angioplasty in After achieving success with coronary angioplasty in animals, Gruentzig and his colleagues performed the animals, Gruentzig and his colleagues performed the 1st intraoperative balloon angioplasty on the human 1st intraoperative balloon angioplasty on the human heart. Soon, Gruentzig accomplished the 1st coronary heart. Soon, Gruentzig accomplished the 1st coronary angioplasty in a patient who was awake.angioplasty in a patient who was awake.

Coronary AngioplastyCoronary Angioplasty

19771977 - Gruentzig performed balloon angioplasty on an - Gruentzig performed balloon angioplasty on an isolated stenosis of the proximal left anterior isolated stenosis of the proximal left anterior descending coronary artery. The Gruentzig technique descending coronary artery. The Gruentzig technique took the cardiology community by storm, and the era took the cardiology community by storm, and the era of interventional cardiology was born. of interventional cardiology was born.

An international registry of PTCA was established to An international registry of PTCA was established to provide a method for systematic evaluation of this provide a method for systematic evaluation of this new procedure.new procedure.

Even after Gruentzig's death in Even after Gruentzig's death in 19851985, his technique , his technique continued to evolve and subsequently led to continued to evolve and subsequently led to applications such as coronary atherectomy (applications such as coronary atherectomy (19861986) and ) and coronary stenting (coronary stenting (19871987). ).

By By 19971997, angioplasty had become one of the most , angioplasty had become one of the most common medical interventions in the world. common medical interventions in the world.