ABSTRACT Coordinated and harmonic (synchronous) ventricular electrical activation is essential for better left ventricular systolic function. Intraventricular conduction abnormalities, such as left bundle branch block due to artificial cardiac pacing, lead to electromechanical “dyssynchronopathy” with deleterious structural and clinical consequences. The aim of this review was to describe and improve the understanding of all the processes connecting the several mechanisms involved in the development of artificially induced ventricular dyssynchrony by cardiac pacing, most known as pacing-induced cardiomyopathy (PiCM). The chronic effect of abnormal impulse conduction and nonphysiological ectopic activation by artificial cardiac pacing is suspected to affect metabolism and myocardial perfusion, triggering regional differences in the activation/contraction processes that cause electrical and structural remodeling due to damage, inflammation, and fibrosis of the cardiac tissue. The effect of artificial cardiac pacing on ventricular function and structure can be multifactorial, and biological factors underlying PiCM could affect the time and probability of developing the condition. PiCM has not been included in the traditional classification of cardiomyopathies, which can hinder detection. This article reviews the available evidence for pacing-induced cardiovascular disease, the current understanding of its pathophysiology, and reinforces the adverse effects of right ventricular pacing, especially right ventricular pacing burden (commonly measured in percentage) and its repercussion on ventricular contraction (reflected by the impact on left ventricular systolic function). These effects might be the main defining criteria and determining mechanisms of the pathophysiology and the clinical repercussion seen on patients. synchronous (synchronous abnormalities dyssynchronopathy “dyssynchronopathy consequences pacinginduced PiCM. . (PiCM) perfusion activationcontraction damage inflammation tissue multifactorial condition cardiomyopathies detection disease commonly percentage reflected function) patients (PiCM

ABSTRACT Coordinated and harmonic (synchronous) ventricular electrical activation is essential for better left ventricular systolic function. Intraventricular conduction abnormalities, such as left bundle branch block due to artificial cardiac pacing, lead to electromechanical “dyssynchronopathy” with deleterious structural and clinical consequences. The aim of this review was to describe and improve the understanding of all the processes connecting the several mechanisms involved in the development of artificially induced ventricular dyssynchrony by cardiac pacing, most known as pacing-induced cardiomyopathy (PiCM). The chronic effect of abnormal impulse conduction and nonphysiological ectopic activation by artificial cardiac pacing is suspected to affect metabolism and myocardial perfusion, triggering regional differences in the activation/contraction processes that cause electrical and structural remodeling due to damage, inflammation, and fibrosis of the cardiac tissue. The effect of artificial cardiac pacing on ventricular function and structure can be multifactorial, and biological factors underlying PiCM could affect the time and probability of developing the condition. PiCM has not been included in the traditional classification of cardiomyopathies, which can hinder detection. This article reviews the available evidence for pacing-induced cardiovascular disease, the current understanding of its pathophysiology, and reinforces the adverse effects of right ventricular pacing, especially right ventricular pacing burden (commonly measured in percentage) and its repercussion on ventricular contraction (reflected by the impact on left ventricular systolic function). These effects might be the main defining criteria and determining mechanisms of the pathophysiology and the clinical repercussion seen on patients.

Resumo A farmacogenômica (FGx) investiga a interação entre genes e medicamentos. Através da análise de regiões específicas do DNA, informações sobre o perfil de metabolização do paciente para um determinado fármaco podem ser descritas, assim como o perfil esperado de resposta ao tratamento. Objetivamente, esse tipo de teste pode ter impacto no tratamento de pacientes que não estão respondendo adequadamente a um determinado medicamento, seja pela ausência dos efeitos esperados ou em virtude do aparecimento de efeitos adversos. Neste cenário, o objetivo desta revisão é o de informar o cardiologista clínico sobre esta importante área do conhecimento e atualizá-lo sobre o tema, procurando preencher as lacunas no que diz respeito à relação custo-benefício da aplicação da FGx nas doenças cardiovasculares, além de fornecer informações para a implementação da terapia guiada pela FGx na prática clínica.