AVALIAÇÃO DA ESTIMULAÇÃO CARDÍACA ARTIFICIAL FISIOLÓGICA VERSUS ESTIMULAÇÃO CONVENCIONAL EM PACIENTES COM DISTÚRBIOS DE CONDUÇÃO CARDÍACA
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Data
2024
Autores
Orientador
Timmers, Luís Fernando Saraiva Macedo
Banca
Alves, Alessandro Menna
Silva, Guilherme Liberato Da
Bartholomay, Eduardo
Título do periódico
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Resumo
A estimulação cardíaca artificial (ECA) consiste em realizar um estímulo elétrico com intuito de capturar o músculo cardíaco, gerando assim uma contração ventricular. Esse estímulo é gerado por um dispositivo chamado de marcapasso (MP) artificial. Composto por cabos e gerador, é um dispositivo implantado cirurgicamente e, por via transvenosa, realiza o contato de uma das extremidades com o miocárdio do paciente, sendo responsável por identificar a atividade elétrica e realizar o estímulo sempre que necessário. Convencionalmente com a sua extremidade distal posicionada no ápice do ventrículo direito, o eletrodo estimula a porção mais distal dessa cavidade, contrariando a ativação fisiológica esperada; gerando assim, uma dessincronia mecânica da contração miocárdica. Essa estimulação cardíaca convencional corrige a disfunção elétrica e hemodinâmica causada pela queda da frequência cardíaca; no entanto, ocasiona um efeito mecânico deletério à função ventricular esquerda e consequentemente, dilatação ventricular e piora do débito cardíaco (DC). Tal mecanismo caracteriza a miocardiopatia associada à estimulação cardíaca artificial (MECA). Recentemente, técnicas para amenizar os efeitos deletérios da estimulação cardíaca foram desenvolvidas. Denominada de estimulação fisiológica, a estimulação com o eletrodo diretamente no sistema nativo de condução ventricular é capaz de mimetizar uma ativação ventricular fisiológica; proporcionando assim, menores disfunções elétricas e mecânicas e reduzindo a incidência de insuficiência cardíaca associada à estimulação artificial. O presente projeto de pesquisa avaliou por meio de um estudo de coorte retrospectivo, baseado em análise de prontuários, exames e funcionamento dos dispositivos, a indicação e o perfil clínico dos pacientes submetidos a implante de MP convencional em hospital de referência em cardiologia do interior do estado do Rio Grande do Sul e pacientes submetidos a implante de MP fisiológico em serviço de referência em ECA de Porto Alegre, no período de 01 de janeiro de 2019 até 28 de fevereiro de 2021. Foram analisadas as idades dos pacientes no momento do implante, o diagnóstico da doença de base, a função ventricular, a duração do 6 QRS, as dimensões e volumes do ventrículo esquerdo e o percentual de estimulação ventricular, todas essas variáveis pré impante e após 1 ano do implante do MP. Os pacientes submetidos ao implante de MP convencional eram mais jovens (p=0,02), apresentaram-se com QRS mais alargado (p=<0,0001) e obtiveram 18% mais chance de obter um QRS alargado (p=0,01) Observou-se que paciente submetidos a implante de MP convencional tiveram mais estimulação ventricular. Contudo, a escolha do tipo de dispositivo implantável que melhor beneficia o paciente depende de algumas características clínicas e eletrocardiográficas, não sendo a técnica ainda indicada como tratamento de eleição a todos os pacientes que necessitem de estimulação artificial.
Cardiac pacing, or artificial cardiac stimulation (ACS), involves delivering an electrical stimulus to capture the cardiac muscle, thereby generating a ventricular contraction. This stimulus is generated by a device known as an artificial pacemaker (AP). Comprising cables and a generator, it is a surgically implanted device that, via transvenous means, makes contact with the patient's myocardium, responsible for identifying electrical activity and delivering the stimulus when needed. Conventionally, with its distal end positioned at the apex of the right ventricle, the electrode stimulates the most distal portion of this cavity, contradicting the expected physiological activation and resulting in mechanical desynchronization of myocardial contraction. While conventional cardiac stimulation corrects the electrical and hemodynamic dysfunction caused by a drop in heart rate, it has a deleterious mechanical effect on left ventricular function, leading to ventricular dilation and worsening of cardiac output. This mechanism characterizes myocardiopathy associated with artificial cardiac stimulation (MAACS). Recently, techniques to mitigate the deleterious effects of cardiac stimulation have been developed. Termed physiological stimulation, the stimulation with the electrode directly in the native ventricular conduction system is capable of mimicking physiological ventricular activation, thereby causing fewer electrical and mechanical dysfunctions and reducing the incidence of heart failure associated with artificial stimulation. The present research project evaluated, through a retrospective cohort study based on chart analysis, examinations, and device functionality, the indications and clinical profiles of patients undergoing conventional AP implantation at a cardiology reference hospital in the interior of Rio Grande do Sul and patients undergoing physiological AP implantation at a cardiac stimulation reference service in Porto Alegre, from January 1, 2019, to February 28, 2021. Patient ages at the time of implantation, underlying disease diagnosis, ventricular function, QRS duration, left ventricular dimensions and volumes, and the percentage of ventricular stimulation were analyzed, both pre-implantation and one year post-implantation. 8 Patients undergoing conventional AP implantation were younger (p=0.02), had a wider QRS complex (p=<0.0001), and were 18% more likely to have a widened QRS complex (p=0.01). It was observed that patients undergoing conventional AP implantation had more ventricular stimulation. However, the choice of the type of implantable device that best benefits the patient depends on certain clinical and electrocardiographic characteristics, and the technique is not yet recommended as the first-line treatment for all patients requiring artificial stimulation.
Cardiac pacing, or artificial cardiac stimulation (ACS), involves delivering an electrical stimulus to capture the cardiac muscle, thereby generating a ventricular contraction. This stimulus is generated by a device known as an artificial pacemaker (AP). Comprising cables and a generator, it is a surgically implanted device that, via transvenous means, makes contact with the patient's myocardium, responsible for identifying electrical activity and delivering the stimulus when needed. Conventionally, with its distal end positioned at the apex of the right ventricle, the electrode stimulates the most distal portion of this cavity, contradicting the expected physiological activation and resulting in mechanical desynchronization of myocardial contraction. While conventional cardiac stimulation corrects the electrical and hemodynamic dysfunction caused by a drop in heart rate, it has a deleterious mechanical effect on left ventricular function, leading to ventricular dilation and worsening of cardiac output. This mechanism characterizes myocardiopathy associated with artificial cardiac stimulation (MAACS). Recently, techniques to mitigate the deleterious effects of cardiac stimulation have been developed. Termed physiological stimulation, the stimulation with the electrode directly in the native ventricular conduction system is capable of mimicking physiological ventricular activation, thereby causing fewer electrical and mechanical dysfunctions and reducing the incidence of heart failure associated with artificial stimulation. The present research project evaluated, through a retrospective cohort study based on chart analysis, examinations, and device functionality, the indications and clinical profiles of patients undergoing conventional AP implantation at a cardiology reference hospital in the interior of Rio Grande do Sul and patients undergoing physiological AP implantation at a cardiac stimulation reference service in Porto Alegre, from January 1, 2019, to February 28, 2021. Patient ages at the time of implantation, underlying disease diagnosis, ventricular function, QRS duration, left ventricular dimensions and volumes, and the percentage of ventricular stimulation were analyzed, both pre-implantation and one year post-implantation. 8 Patients undergoing conventional AP implantation were younger (p=0.02), had a wider QRS complex (p=<0.0001), and were 18% more likely to have a widened QRS complex (p=0.01). It was observed that patients undergoing conventional AP implantation had more ventricular stimulation. However, the choice of the type of implantable device that best benefits the patient depends on certain clinical and electrocardiographic characteristics, and the technique is not yet recommended as the first-line treatment for all patients requiring artificial stimulation.
Descrição
Palavras-chave
bradicardia; marcapasso; estimulação cardíaca fisiológica; insuficiência cardíaca; bradycardia; pacemaker; physiological cardiac stimulation; cardiac insufficiency
Citação
CABRAL, Gustavo Chiari. AVALIAÇÃO DA ESTIMULAÇÃO CARDÍACA ARTIFICIAL FISIOLÓGICA VERSUS ESTIMULAÇÃO CONVENCIONAL EM PACIENTES COM DISTÚRBIOS DE CONDUÇÃO CARDÍACA. 2023. Dissertação (Mestrado) – Curso de Ciências Médicas, Universidade do Vale do Taquari - Univates, Lajeado, 07 jun. 2023. Disponível em: http://hdl.handle.net/10737/4342.