Marc W. Deyell, MD, FRCPC, Stanley Tung, MD, FRCPC, Andrew Ignaszewski, MD, FRCPC The implantable cardioverter- defibrillator: From Mirowski to its current use Sudden cardiac death can be prevented in two broad categories of patients—those who have survived a life-threatening ventricular arrhythmia or who have sustained ventricular tachycardia, and those who have not experienced sudden cardiac arrest but are known to be at increased risk. ABSTRACT: Sudden cardiac death y the mid-20th century it Michel Mirowski is the initial presentation for many was well known that ven- Mieczyslaw (Michel) Mirowski was patients with cardiac disease. Dr tricular arrhythmias were born 14 October 1924 in Warsaw, Michel Mirowski was a pioneering Bthe mechanism of death in a Poland.4 The story of his early life is cardiologist who recognized the large proportion of patients with car- nothing short of incredible. He grew public health importance of this diac disease. The 1960s brought with up in a middle-class family among the fact. In the 1970s his efforts led to them the advent of electronic moni- large Jewish population of Warsaw at the development of the implantable toring, cardiopulmonary resuscita- that time, but his relatively comfort- cardioverter-defibrillator that has tion, and synchronized cardiover- able life changed dramatically with revolutionized the ability to prevent sion.1-3 Once clinicians had tools at the outbreak of the Second World War. and treat sudden cardiac arrest. their disposal for the treatment of ven- With the invasion of Poland by the However, in the first decade of the tricular arrhythmias, it was not sur- Nazis in 1939, Michel knew he could 2000s these devices remain under- prising to see the first coronary care not stay in Poland, but he was deter- utilized in British Columbia and units opened in 1962.2 mined to continue his education. There- Canada. Increased physician aware- While considerable attention was fore, at the age of 15, he made the deci- ness is needed regarding which being paid to the treatment of arrhyth- sion to leave his family and flee to patients are at high risk of sudden mias among hospitalized patients, lit- Russia along with a friend. He would cardiac death and would benefit from tle attention was being paid to the be the only member of his family to this potentially lifesaving therapy. major public health problem of sud- survive the Second World War. den cardiac death (SCD) outside the Mirowski spent the following 5 coronary care unit.4 SCD is the initial years of the war in the Soviet Union, presentation of cardiac disease in 15% fleeing the advancing Germans. Des - of patients5 and more than 50% of all pite long odds, he continually evaded such deaths occur out of hospital.6 Michel Mirowski was one of the few Dr Deyell is an electrophysiology fellow at clinicians in the 1960s to recognize the University of British Columbia and is the scope of the problem of SCD. It based at St. Paul’s Hospital. Dr Tung is an was his perseverance that ultimately electrophysiologist at St. Paul’s Hospital led to the development of the first suc- and a clinical assistant professor at UBC. cessful therapy for out-of-hospital Dr Ignaszewski is a clinical professor of cardiac arrest—the implantable car- medicine and head of the UBC Division of dioverter-defibrillator (ICD). Cardiology. 248 BC MEDICAL JOURNAL VOL. 52 NO. 5, JUNE 2010 www.bcmj.org The implantable cardioverter-defibrillator: From Mirowski to its current use Russian authorities who were intent nal defibrillator paddle, on a dog.9 Mower were involved in many of the on sending refugees to labor camps in The paper describing their work was early refinements, including the devel- Siberia. Somehow, he always man- eventually published after initial opment of the capacity of synchro- aged to find enough work to feed him- rejections,10 but there remained con- nized cardioversion for ventricular self and to stave off the malnutrition siderable antagonism in the cardiolo- tachycardia.9 True to Mirowski’s orig- and disease that was rampant in the gy community toward the concept of inal vision, a catheter-electrode-based Soviet Union at that time. the ICD. The antagonism also meant model developed in the late 1980s After the war ended, Mirowski that they faced significant difficulty in could be implanted without a thoraco- briefly returned to Poland and began securing funding for their research. tomy, in a similar manner to the stan- medical school in Gdansk before leav- Mirowski and Mower eventually dard pacemaker. ing to pursue his medical education in obtained support from a major pace- In the late 1980s Mirowski was Western Europe. He eventually enter - maker company in 1970 to further diagnosed with multiple myeloma and ed medical school in Lyon, France, in develop the ICD, but after 2 years the he succumbed to the disease in 1990. 1947, despite knowing almost no company decided there was no mar- While his invention of the ICD was an French or English. It was in Lyon ket for the device. In 1972 Mirowski enormous advance for cardiac medi- where Mirowski was first attracted to was introduced to Stephen Heilman, cine, perhaps his greatest legacy was cardiology and also where he met and a physician and engineer who had the attention he drew to the problem fell in love with his wife, Anna. formed a small medical equipment of SCD as a whole. Upon graduation from medical company called Medrad. Heilman was school in 1954, he worked initially in excited by the concept of the ICD and ICDs in 2010 Tel Aviv, Israel, as a registrar and then immediately put the company’s engi- Unlike the early prototypes, modern pursued further training in Mexico neers at Mirowski and Mower’s dis- devices are much smaller, with the City, Baltimore, and Staten Island. He posal. The partnership was fruitful and newest models weighing as little as return ed to Israel in 1963 to set up a resulted in the production of the first 90 g and measuring less than a cen- private practice in a small community ICD prototype small enough to be timetre thick. In addition to having hospital. His new boss, Professor completely implanted in a dog in full pacemaker capabilities, all mod- Harry Heller, unwittingly became the 1975. A film of the first successful ern ICDs are capable of overdrive pac- inspiration for Mirowski’s research. defibrillation of a dog implanted with ing (antitachycardia pacing), which In 1966 Heller began having episodes the prototype ICD was released and can often terminate ventricular tachy- of ventricular tachycardia and died the now-famous footage catapulted cardia without resorting to shock soon after. It was with Heller’s death the ICD from relative obscurity to the therapy. ICDs are also available with that Mirowski first conceived the idea forefront of cardiac research overnight. biventri cular pacing (cardiac resyn- of an implantable defibrillator. Mirowski and the group at Medrad chronization therapy) to improve symp- further refined the prototype to make toms in selected patients with ad - Development of the ICD it suitable for human implantation and vanced heart failure. In 1968 Mirowski was recruited to the eventually received approval for such The use of ICDs in Canada and Sinai Hospital in Baltimore, where he an implant from the FDA. After Mirow - around the world has grown consider- became the director of the hospital’s ski and Mower enlisted the aid of col- ably since 1980. In 2008, 593 ICDs new coronary care unit and was given leagues at Johns Hopkins Hospital, were implanted in British Columbia protected time for research. Fortu- cardiac surgeon Myron Weisfeldt and and 5811 were implanted across Cana- nately for this research, the hospital electrophysiologist Philip Reed, the da. Although these numbers are ex - had a division of biomedical engi- first successful human implant of an pected to rise in the years to come, neering and an animal laboratory.7 At ICD was performed in February 1980.11 ICDs currently remain underutilized the Sinai, Mirowski joined with Mor- Though the first ICD model was a in Canada, even among survivors of ton Mower, a junior cardiologist on success, it weighed 225 g, required a cardiac arrest.12 staff with extensive animal research thoracotomy for implantation of the experience, to begin work on an ICD electrode patches, and was only capa- Patient selection in July 1969.8 Only a month later they ble of defibrillation. In the years that Whether to implant an ICD in a par- successfully tested their first crude followed, numerous advances in ICD ticular patient is a complex decision prototype, made from a broken exter- design have been made. Mirowski and and involves careful discussion among www.bcmj.org VOL. 52 NO. 5, JUNE 2010 BC MEDICAL JOURNAL 249 The implantable cardioverter-defibrillator: From Mirowski to its current use the health care providers and the pa - vs 16% for ICD vs placebo). The num- complex. Implantation is not without tient. The ultimate decision to implant ber needed to treat to prevent one risk, including inappropriate shocks, an ICD rests with the cardiac electro- death over 2 years was 12 patients and device recall or malfunction, and in - physiologist, who will be responsible the cost per life-year saved by an ICD creased hospitalization. Devices also for appropriate programming and was estimated at US$66 677 in 2002.16 remain expensive and require long- long-term follow-up of the device. It Based on these trials, the 2005 Cana- term follow-up at specialized centres is important for the other treating dian Cardiovascular Society/Canadian experienced in their management.