Relationship of Electromechanical Dyssynchrony in Patients Submitted to CRT With LV Lead Implantation Guided by Gated Myocardial Perfusion Spect

Abstract

BackgroundHeart failure (HF) affects more than 5 million individuals in the United States, with more than 1 million hospital admissions per year. Cardiac resynchronization therapy (CRT) can benefit patients with advanced HF and prolonged QRS. A significant percentage of patients, however, does not respond to CRT. Electrical dyssynchrony isolated might not be a good predictor of response, and the last left ventricular (LV) segment to contract can influence the response.ObjectivesTo assess electromechanical dyssynchrony in CRT with LV lead implantation guided by GATED SPECT.MethodsThis study included 15 patients with functional class II-IV HF and clinically optimized, ejection fraction of 35%, sinus rhythm, left bundle-branch block, and QRS ≥ 120 ms. The patients underwent electrocardiography, answered the Minnesota Living with Heart Failure Questionnaire (MLHFQ), and underwent gated myocardial perfusion SPECT up to 4 weeks before CRT, being reassessed 6 months later. The primary analysis aimed at determining the proportion of patients with a reduction in QRS duration and favorable response to CRT, depending on concordance of the LV lead position, using chi-square test. The pre- and post-CRT variables were analyzed by use of Student t test, adopting the significance level of 5%.ResultsWe implanted 15 CRT devices, and 2 patients died during follow-up. The durations of the QRS (212 ms vs 136 ms) and the PR interval (179 ms vs 126 ms) were significantly reduced (p < 0.001). In 54% of the patients, the lead position was concordant with the maximal delay site. In the responder group, the lateral position was prevalent. The MLHFQ showed a significant improvement in quality of life (p < 0.0002).ConclusionCRT determines improvement in the quality of life and in electrical synchronism. Electromechanical synchronism relates to response to CRT. Positioning the LV lead in the maximal delay site has limitations.

Viabilidade do Implante de Eletrodo Ventricular Esquerdo na Terapia de Ressincronização Cardíaca Guiada por Gated SPECT e Remodelamento Ventricular

“…demonstraram melhora da qualidade de vida e relação entre sincronismo eletromecânico e resposta à TRC na posição do eletrodo do VE guiado por gated SPECT. 29 Os nossos achados estão de acordo com os dados de He et al, 30 onde os parâmetros da geometria do VE obtidos pelo gated SPECT foram capazes de predizer a super-resposta à TRC associada à orientação da colocação do eletrodo do VE pelo gated SPECT, no qual observamos uma alteração significativa da variável de excentricidade do VE tanto na sístole quanto na diástole do VE, denotando o remodelamento reverso após a TRC guiada por gated SPECT. Um achado significativo em nossos dados é que, na posição discordante do eletrodo do VE em 2 pacientes, a variável de excentricidade comportouse de forma diferente das demais posições, não levando ao remodelamento reverso, com piora da geometria do VE.…”

Cardiologia Nuclear na Otimização da Terapia de Ressincronização: Quo Vadis?

“…8 Another factor that should be considered in the analysis of these studies is the difficulty in correctly positioning the electrode. Nascimento et al, 9 evaluating a small group of patients, demonstrated DOI: https://doi.org/10.36660/abc.20230136…”

“…This is an open-access article distributed under the terms of the Creative Commons Attribution License that properly positioning the electrode in the last segment contracting was possible in only 54% of patients. 9 In the Arquivos Brasileiros de Cardiologia, Nascimento et al 10 evaluated the feasibility of implantation LV lead guided by phase analysis and its relationship to ventricular remodeling. In a small sample, 18 patients with an indication for CRT performed myocardial scintigraphy for implant orientation, and eccentricity and ventricular shape parameters were evaluated.…”

“… 8 Outro fator que deve ser considerado na análise desses estudos é a dificuldade em posicionar corretamente o eletrodo. Nascimento et al, 9 avaliando um pequeno grupo de pacientes, demonstraram que o posicionamento adequado do eletrodo na contração do último segmento foi possível em apenas 54% dos pacientes. 9 …”

“…Nascimento et al, 9 avaliando um pequeno grupo de pacientes, demonstraram que o posicionamento adequado do eletrodo na contração do último segmento foi possível em apenas 54% dos pacientes. 9 …”