The Development of Pacemaker Programming: Memories From a Bygone Era.

Programmability is a stable, reversible change in the operating parameters of a cardiac implantable electronic device. The era of non-invasive programming began in 1972, with the development of a dedicated hand-held battery-operated device. Prior to this, there had been crude attempts, involving invasive procedures or a magnet, to change the pacemaker operating parameters. A non-invasive programming system requires an implanted pulse generator and an external programmer, communicating via an energy link. This was initially a pulsed magnetic field allowing opening and closing of a reed switch in the pulse generator in synchrony with the pulses. Soon after, radiofrequency communication was introduced and involved transmission of pulsing on-off radiofrequency bursts, which allowed complex encoding, that recognised the implanted hardware, prevented mis-programming, had security features and confirmed successful programming. As programming became more complex and sophisticated, programmers evolved into desktop models with programming wands and printers. By 1978, multiprogrammable programmers with bidirectional telemetry were introduced and became a driving force in the development of new cardiac implantable technologies and devices.

Rate Adaptive Pacing: Memories From a Bygone Era.

With the recognised physiologic value of dual chamber pacing, there was, at the commencement of the 1980s, an intense search for sensors to enable ventricular pacemakers to alter the pulse repetition rate in response to physiologic demand. Manufacturers fell into two main groups; those who chose highly physiologic sensors often requiring special pacing leads and those whose sensors allowed a standard pacing lead. Thirteen (13) sensors for rate adaptive pacing progressed at least to human investigational studies. Eventually the activity sensor, which responded quickly to exercise, but not to emotional stimuli or pyrexia and used a standard lead would predominate, with all manufacturers eventually accepting what was the least physiologic sensor investigated. The activity-based rate response was not dependent on cardiac or pulmonary disease, which could nullify the response with many of the other sensors. Three (3) other sensors survived that period and are still available today; minute ventilation, closed loop stimulation and central venous temperature, with the first two incorporated with activity as dual sensor systems. This review will outline the development of all the sensors used for rate adaptive pacing.

The Cardiac Pacemaker Clinic: Memories From a Bygone Era.

In 1963, soon after the first ventricular pacemakers were implanted at the Royal Melbourne Hospital, attempts were made to identify impending pacing failure, thus preventing sudden death in these very vulnerable patients. By 1970, patient numbers had increased, a formal regular pacemaker clinic was established, and guidelines and protocols developed. The clinic was staffed by a physician, a biomedical engineer and cardiac technicians. The unipolar, asynchronous, non-programmable pulse generators were powered by mercuric oxide/zinc batteries and implanted in the abdomen, using either transvenous or epimyocardial leads. Although, pulse generators were electively replaced at 3 years, most had already been replaced because of power source depletion, electronic failure or lead issues. Testing in all patients involved an electrocardiographic rhythm strip and electronic analysis of the stimulus artefact using a calibrated high-speed storage oscilloscope. Results were compared to previous studies and significant changes were interpreted as impending power source depletion. As a result of this testing, 97% of cases of impending power source depletion were detected prior to failure. These findings allowed testing each 4 months and for pulse generator life to be extended beyond three years. With ventricular triggered pulse generators, new testing procedures were designed. With time, visiting regional centres and clinical evaluation of new products became important functions of the clinic.

Half a century of continuous pacing: a living witness to the evolution of a technology.

To chart the development of pacing technology and its pitfalls we present the experience of a patient who has benefitted from it but also suffered as a result of it from its earliest days. A 53-year-old physician was referred to us with obstruction of the superior and inferior vena cava on a background of more than 50 years of continuous ventricular pacing and 24 previous pacemaker-related interventions. In a single surgical procedure, his existing pacing system and redundant leads were extracted, the superior vena cava was reconstructed, and a new biventricular pacing system with epicardial leads was implanted. Pacemakers can maintain life and preserve the quality of life for many decades. The quality of this therapy has improved due to advances in the technology and in techniques. Maintaining safe pacing in the very long term requires labour, patience, and ingenuity.

Cardiac pacemakers: a basic review of the history and current technology.

In the 60 years since the first human implant of a cardiac pacemaker, tremendous improvements have been made to devices themselves as well as the lead systems. Improvement in battery materials has allowed for production of smaller devices with greater longevity and a vast array of technologies allowing for communication between the device and the operator. Lead wires, typically to as the weakest part of the pacing system, have also seen a metamorphosis as improvements in conductor materials and hybrid insulation have been shown to improve reliability. With the recent development of leadless pacing systems, the downfalls of implantable leads can be avoided. These improvements have allowed a more widespread use of cardiac pacing in veterinary applications since the first reported canine implant in 1967.

Avaliação do desempenho elétrico de um cabo-eletrodo bipolar endocárdico de fixação ativa estimulação atrial direita / Evaluation of the electrical performance of a bipolar active fixation endocardial lead in right atrial pacing

Introdução:A evolução da tecnologia envolvida no desenvolvimento e na construção dos cabos-eletrodosvisa a melhorar seu desempenho elétrico na prática clínica da estimulação cardíaca artificial, otimizando o usodos sistemas e tornando-os mais duradouros, sem perder a eficácia. Neste estudo, objetivou-se avaliar a efetividadee a segurança de um cabo-eletrodo bipolar endocárdico de fixação ativa St. Jude, modelo Tendril 2088TC®.Método:Foi realizada uma análise prospectiva de 43 pacientes submetidos a implante atrial direito do modelo emquestão, dos quais 26 (60%) eram do sexo feminino. Os valores de limiar de estimulação, sensibilidade da ondaP e impedância foram compilados em quatro momentos da evolução clínica de cada paciente: no implante, naalta hospitalar, 30 dias após o implante e com três meses de evolução. Ao final do período de estudo, 41 pacientescompletaram o seguimento.Resultados:Após análise estatística, os resultados demonstraram desempenhoelétrico favorável, com valores crônicos estáveis.Conclusão:Conclui-se que o referido cabo-eletrodo é eficiente eseguro na rotina do serviço de marcapasso.

Background:The evolution of the technology used for the development and construction of leads,is aimed at improving their electrical performance in the clinical practice of artificial cardiac pacing, optimizingsystems for a longer duration without losing their efficacy. The objective of this study is to evaluate the efficacyand safety of the St. Jude’s bipolar active fixation endocardial lead, model Tendril 2088TC®.Method:Prospectivestudy of 43 patients undergoing right atrial implantation using the model above, of which 26 (60%) were female.The threshold values for stimulation, P-wave sensitivity and impedance were collected at 4 timepoints duringthe clinical follow-up of each patient: at the time of implantation, at hospital discharge, 30 days and 3 monthsafter implantation. At the end of the study period 41 patients concluded the follow-up.Results:After statisticalanalysis, the results demonstrated a favorable electrical performance, with stable chronic values.Conclusion:Thelead above is safe and effective for use in routine pacemaking practice.

Estimulação cardíaca artificial bifocal de segurança: relato de caso e revisão de literatura / Safety bifocal pacing: case report and literature review

Relatam-se dois casos de pacientes portadores de marcapasso definitivo bifocal direito de segurança, totalmente dependentes de estimulação cardíaca artificial. Durante o seguimento, em ambos ocorreu perda da estimulação por um dos cabos-eletrodos ventriculares. A estimulação foi mantida pelo segundo cabo-eletrodo e os pacientes não relataram sintomas. A estimulação cardíaca bifocal deve ser considerada em pacientes altamente dependentes da estimulação artificial ou ainda naqueles submetidos à estimulação cardíaca por via epicárdica...

We describe two cases of patients with right bifocal pacing, totally dependent on cardiac pacing. During follow-up, in both cases occurred exit block of one ventricular lead. The pacing was kept by the other lead and the patients reported no symptoms, showing the value of the bifocal pacing in those patients highly dependent on cardiac pacing or in patients undergoing epicardial pacing...

Evoluçãode crianças com idade inferior a 2 anos submetidas a implante de marcapasso cardíaco permanente / late results with permanent cardiac pacing in children less than two years of age

A estimulação epicárdica predomina no implante de marcapasso em crianças pequenas. Objetivo: revisar a evolução de pacientes menores de dois anos submetidos a estimulação epimiocárdica após a alta hospitalar e até uma década. Método: Estudo de coorte histórica entre 1997 e 2010 que incluiu 34 pacientes, 22 (64,7%) do sexo feminino e 12 (35,3%) do masculino, com idades variando de 1 dia a 22 meses, submetidos a implante de marcapasso utilizando cabo-eletrodo epimiocárdico sem sutura e gerador unicameral (VVI). A arritmia pre dominante foi o bloqueio atrioventricular (n=30; 88,2%); 29 (85,3%) tinham cardiopatia estrutural e 22 (67,4%) haviam sido previamente submetidos a cirurgia cardíaca. Acompanhados durante um tempo médio de 60,5 meses, tiveram registrados os eventos adversos e calculada a probabilidade de sobrevida conforme Kaplan-Meyer. Resultados: Ocorreram três óbitos (8,8%) por infecção, cirurgia cardíaca ou mal súbito. A mortalidade foi superior naqueles sem cirurgia cardíaca prévia (16,7% versus 4,5%). Ao longo do acompanhamento, cinco pacientes (14,7%) necessitaram de nova intervenção, dois por infecção e três para reimplante de cabo-eletrodo. Um dos pacientes submetidos a nova intervenção por infecção evoluiu para óbito. A probabilidade de sobrevida foi de 93,8% no primeiro ano e 90,3% até 10º ano. A sobrevida livre de eventos adversos foi de 90,8% no primeiro ano, 79,8% do 5º ao 9º e 66,5% no 10º ano. Conclusão: Os resultados evidenciam sobrevida satisfatória das crianças após o implante epicárdico, especialmente aquelas com cirurgia cardíaca prévia. O implante de cabo-eletrodo epimiocárdico merece cuidados adicionais em pacientes com estatura reduzida, malformações cardíacas específicas, acesso dificultado à veia cava superior ou com procedimento cirúrgico associado...

Objective: Epicardial stimulation remains the technique of choice for pacing in small children. Our objective is to review the results of epicardial pacemaker implantation in patients with less than 2 years of age and after hospital discharge. Methods: Historical cohort study including 34 patients with age ranging from one day to 22 months with hospital discharge after permanent pacemaker implantation with a sutureless epimyocardial electrode and single chamber generator (VVI mode) between 1997 and 2010. Twenty-two patients were female and 12 male. Predominant arrhythmia was atrioventricular block (30 patients; 88.2%). Twenty-nine patients (85.3%) had structural heart disease and 22 (67.4%) had been submitted to a previous heart surgery. Patients were followed-up for a mean time of 60.5 months. Recorded events were analyzed and probability of survival was estimated according to Kaplan-Meyer analysis. Results: There were 3 (8.8%) deaths, due to infection, heart surgery or sudden death. Increased mortality was observed for patients without previous heart surgery (16.7% versus 4.5%). Five patients (14.7%) required pacemaker reintervention during the follow-up, 2 due to infection and 3 to re-implant the electrode. One of the patients who had a reintervention due to infection died. Probability of survival was 93.8% in the first year and 90.3% subsequently up to the 10 years of follow-up. Event-free survival was 90.8% in the first year, 79.8% from year 5 to 9, 66.5% after 10 years. Conclusion: This study demonstrates the probability of satisfactory survival after epicardial pacemaker implantation, especially in patients with previous heart surgery. Epimyocardial electrode implantation deserves consideration in patients with small physical structure, those with specific cardiac malformations, and difficult access to superior vena cava or those who need to have an associated surgical procedure...

A short history on pacemakers.

Artificial pacemakers have taken part or possibly driven many developments in cardiac science and medicine and are therefore a very important story to remember. This 300-year journey of discovery has been contributed to by experts from across the Globe. The essential foundation of knowledge such as basic electrophysiology and applied electrotherapy was built in the 18th century and is now academically and socially accepted. This line of inventions and research has seen: early use of meta-analyses, the initial coming together of medical or bioengineering and the concept of cardiac monitoring--now a mainstay in the hospital care of a patient. In the 21st century pacemaker developments are no longer solely about reducing mortality but improving morbidity. Design developments reduce: discomfort, additional surgeries and invasive procedures. New energy sources have become lighter, smaller and with a longer life span.

Estimulação elétrica: marca-passo e ressincronizadores / Electrical stimulation: pacemakers and resynchronizers

Desde o advento do primeiro marca-passo artificial implantável em outubro de 1958, na cidade de Estocolmo-Suécia, a estimulação cardíaca artirficial apresentou uma evolução fantástica. Os marca-passos sofreram miniaturização, diminuindo importantemente suas dimensões, aumentaram espetacularmente a longevidade e performance, passando a ser implantados por via endocavitária através de procedimento minimamente invasivo. Hoje os marca-passos cardíaco, além da função terapêutica, restabelecendo a frequência cardíaca normal e adequando-a às necessidades metabólicas a que se encontra o paciente, apresentam tabém função diagnóstica, monitorando constantemente o ritmo cardíaco, podndo armazenar arritmias cardíacas definidas por programação e evidencia-las quando da interrogação do dispositivo. Essas informações pdoem também ser acessadas pela clínica (serviço) ou pelo médico por meio do monitoramento rmoto, disponível atualmente em todos os marca-passos. O monitoramento também propicia mensagens de alertas, no caso de ser identificada uma arritmia grave ou problemas relevantes com o sistema, que podem ser enviadas diretamente ao médico até mesmo por SMS via celulas. Os marca-passoa atuais apresentam excelente performance e persistirão evoluindo, já que não existe limite para o desenvolvimento tecnológico. Em emados da década de 90 do século passado, Baker e Caseau iniciaram uma das funções mais importantes da estimulação cardíaca artificial moderna, a ressincronização cardíaca. A estimulação tripla-câmara biventricular mostrou-se muito eficaz em corrigir a disfunção sistólica causada pela dissincronia ventricular, tratando de maneira eficaz a insuficiência cardíaca refratária à terapêutica medicamentosa otimizada. Necessitando inicialmente de toracotomia para implante do eletrodo do VE, o desenvolvimento da técnica via seio coronariana...

Since the advent of the first implantable artificial pacemaker in October 1958 in Stockholm, Sweden, cardiac pacing artirficial showed a fantastic evolution. Pacemakers suffered miniaturization, important reducing their dimensions, dramatically increased longevity and performance, starting to be deployed via endocavitary through minimally invasive procedure. Today, cardiac pacemakers, besides the therapeutic function, restoring normal heart rate and adjusting it to the patient’s metabolic needs, also having diagnostic function, constantly monitoring the heart rate, and being able to store definite cardiac arrhythmias by programming and highlighting them when the device is questioned. This information can also be accessed by clinical service or by the physician through remote monitoring, currently available in all pacemakers. Remote monitoring also provides alert messages in case of a severe arrhythmia is identified or major problems with the system, which can be sent directly to the doctor even via cell phone by SMS. The current pacemaker have all excellent performance and evolvement, since there is no limit to the technological development. In the mid- 90s of last century, Baker and Caseau began one of the most important functions of modern cardiac pacing, the cardiac resynchronization . Thebi- biventricular triple-chamber pacing proved to be very effective in correcting the systolic dysfunction caused by ventricular dyssynchrony, effectively treating heart failure refractory tooptimized drug therapy. Needing initially thoracotomy to implant the LV, electrode, the development of the technique via coronarysinus ...