IHospital Universitario Francisca Mendes (HUFM), Manaus, AM - Brasil
IIUniversidade Federal do Amazonas (UFAM), Manaus, AM - Brasil
A terapia de ressincronização cardíaca (TRC) é uma modalidade da estimulação cardíaca artificial (ECA) que tem como finalidade corrigir as alterações eletromecânicas em pacientes com insuficiência cardíaca (IC) avançada1. O objetivo maior da TRC é o remodelamento reverso do ventrículo esquerdo (VE)2, com suas diretas implicações, como redução da insuficiência mitral, diminuição do volume sistólico final e volume diastólico final de VE, melhora da fração de ejeção (FE) e débito cardíaco (DC). Consequentemente, a TRC melhora a qualidade de vida, diminui o número de internações hospitalares e aumenta a sobrevida dos pacientes com IC3,4. A ressincronização cardíaca (RC) é realizada preferencialmente através do implante de um eletrodo via seio coronariano (SC) para estimulação do VE, o qual é passível de deslocamento, sendo este um dos problemas desta modalidade de ECA. Relatamos a nossa experiência em tal situação.
Paciente feminino, 32 anos, diagnóstico de miocardiopatia dilatada periparto, IC refratária, fração de ejeção de VE (FEVE) de 19%, com dessincronismo interatrial e interventricular. Implantado um RC tetracâmara, sendo colocado um bifurcador para ressincronização biatrial na saída do canal atrial; a estimulação de câmaras esquerdas foi através do SC. Houve melhora da classe funcional (CF) e na qualidade de vida (QdV). Três meses após implante, apresentou piora significativa da IC e teve uma parada cardiorrespiratória (PCR) recuperada. Constatou-se, através da análise do eletrocardiograma (ECG) e telemetria, perda de comando dos eletrodos de SC e, na radiografia de tórax (RxTx), deslocamento dos eletrodos de SC. Após a estabilização do quadro clínico, foi realizado um reposicionamento dos eletrodos de SC, com subsequente implante de
Paciente feminino 54 anos, diagnóstico de miocardiopatia dilatada idiopática, portadora de marca-passo monocâmara (VVI) por fibrilação atrial (FA) de baixa resposta ventricular. ECG: QRS estimulado de 220 ms; FEVE de 31%. Em CF III-IV com terapia otimizada, foi realizado
Paciente feminino, 31 anos, diagnóstico de miocardiopatia periparto em evolução há mais de 8 meses, com IC descompensada. ECG: Ritmo sinusal com bloqueio atrioventricular de 1º grau e bloqueio de ramo esquerdo (BRE); FEVE de 16%. Durante internação, apresentou PCR sendo reanimada precocemente. Foi implantado um RC associado ao CDI. O controle pós-operatório evidenciava ao RxTx o deslocamento dos eletrodos de átrio direito e SC, sendo necessário seu reposicionamento. Devido à instabilidade do eletrodo de SC, optou-se pela colocação de um
Paciente masculino, 56 anos, com diagnóstico de miocardiopatia dilatada, com FEVE de 31%, ECG com ritmo de FA associado a BRE. Foi indicada a TRC devido à IC refratária a tratamento farmacológico. Durante o implante do eletrodo de SC, tivemos deslocamento do mesmo em repetidas oportunidades; esta instabilidade do eletrodo nos levou a implantar um
Paciente masculino, 65 anos, com antecedentes de IC de etiologia isquêmica, FEVE de 25%, refratária à terapia farmacológica; ECG: ritmo sinusal com BRE, sendo realizada a TRC. Durante o implante do ressincronizador, houve deslocamento do eletrodo de SC repetidas vezes, sendo necessária também a utilização do
A TRC atualmente faz parte do arsenal terapêutico da IC, indicada em pacientes (ptes) com disfunção ventricular grave, refratários à terapia farmacológica e com dessincronismo ventricular1.
O procedimento é realizado com implante de cabo-eletrodo na parede posterolateral do VE, adicional à técnica convencional utilizada para marca-passo atrioventricular (câmaras direitas)1. A via utilizada para estimulação de VE é, preferencialmente, a transvenosa através do SC. O deslocamento do eletrodo de SC durante ou após implante (deslocamento precoce ou tardio) é um dos limitadores do sucesso da TRC, alcançando 5-10% dos casos; provavelmente, isto é devido ao fato de que o eletrodo de SC é posicionado e mantido na veia cardíaca epicárdica de uma forma "passiva", o que facilita o deslocamento e torna necessária uma reintervenção. Galvão e cols.5 descreveram o implante de um "eletrodo âncora" cujo intuito era manter o eletrodo dentro do SC.
Na nossa casuística de cinco pacientes, dois apresentaram deslocamento tardio do eletrodo de SC; um, com deslocamento precoce, e dois, no intraoperatório, com falta de sustentação do eletrodo de SC. Em todos os cinco casos, foram implantados um
A utilização do "
Nossos resultados foram semelhantes aos da literatura; o
Declaro não haver conflito de interesses pertinentes.
O presente estudo não teve fontes de financiamento externas.
Não há vinculação deste estudo a programas de pós-graduação.
Correspondência: Jaime Giovany Arnez Maldonado Rua O, 133, Apto 702, Torre INKA, Cond. Eldorado Park, Parque 10 CEP 69050-290, Manaus, AM – Brasil E-mail:
Artigo recebido em 30/10/11; revisado recebido em 03/11/11; aceito em 07/03/12.
IHospital Universitario Francisca Mendes (HUFM), Manaus, AM - Brazil
IIUniversidade Federal do Amazonas (UFAM), Manaus, AM - Brazil
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Cardiac resynchronization therapy (CRT) is a modality of artificial cardiac stimulation (ACS), whose finality is to correct electromechanical changes in patients with advanced heart failure (HF)1. The major objective of CRT is the reverse remodeling of the left ventricle (LV)2, with its direct implications, such as the reduction in mitral insufficiency, the decrease in LV end-systolic and end-diastolic volumes, and the improvement in ejection fraction (EF) and cardiac output (CO). Consequently, CRT improves quality of life (QoL), decreases the number of hospitalizations and increases the survival of patients with HF3,4. Cardiac resynchronization therapy is preferentially performed with the implantation of an electrode via the coronary sinus (CS) to stimulate the LV; however, that electrode can be dislodged, which is one of the problems of that ACS modality. We report our experience with that situation.
The patient is a 32-year-old female, diagnosed with peripartum dilated cardiomyopathy, refractory HF, LV ejection fraction (LVEF) of 19%, and interatrial and ventricular desynchronization. A four-chamber cardiac resynchronizer (CR) was implanted, and a bifurcador for biatrial resynchronization was placed at the exit of the atrial channel; stimulation of the left chambers was performed through the CS. Both functional class (FC) and QoL improved. Three months after implantation, her HF significantly worsened, and cardiorespiratory arrest (CRA) occurred, but the patient recovered. By use of electrocardiography (ECG) and telemetry, loss of command of the CS electrodes was observed, and, on chest radiography (X-ray), displacement of the CS electrodes was evidenced. After clinical stabilization, the CS electrodes were repositioned, and subsequent supporting stent was implanted on the CS electrode that stimulates the LV. An upgrade of the prosthesis was also performed, and a CR was placed associated with an implantable cardiac defibrillator (ICD). Death occurred after six months of follow-up due to non-cardiovascular problems.
The patient is a 54-year-old female, diagnosed with idiopathic dilated cardiomyopathy, with a single-chamber pacemaker (VVI) because of atrial fibrillation (AF) with slow ventricular response. The ECG showed stimulated QRS of 220 ms. Her LVEF was 31%. The patient was in FC III-IV with optimized therapy, and upgrade to CRT was performed uneventfully, with improvement of the FC and QoL. After five months, her HF worsened, and CRA occurred, but she recovered. Displacement of the CS electrode was also evidenced. A new upgrade to CRT+ICD was performed with repositioning of the CS electrode. After five years, on chest X-ray, an increase in the command threshold of the CS electrode was observed associated with a discrete and late displacement. The LV command was corrected through programing, when elective replacement of the generator was indicated, and, on the same occasion, the SC electrode was also replaced. However, due to repetitive displacements, a supporting stent was implanted to maintain the electrode fixed in the cardiac vein (
The patient is a 31-year-old female, diagnosed with peripartum cardiomyopathy for more than eight months, and decompensated HF. The ECG showed sinus rhythm with first-degree atrioventricular block and left bundle-branch block (LBBB). Her LVEF was 16%. During hospitalization, she had CRA, being reanimated. A CR was implanted associated with an ICD. Post-operative control evidenced, on chest X-ray, displacement of the right atrial and CS electrodes, requiring their repositioning. Due to instability of the CS electrode, a stent was placed in the CS to its stabilization and support. Follow-up of 36 months.
The patient is a 56-year-old male, diagnosed with dilated cardiomyopathy. His LVEF was 31%, and ECG showed AF rhythm associated with LBBB. Because of HF refractory to pharmacological treatment, CRT was indicated. During its implantation, the CS electrode was displaced repeatedly. That instability led to the implantation of a supporting stent to maintain the electrode in the desired position. Follow-up of 18 months.
The patient is a 65-year-old male, with history of ischemic HF (LVEF of 25%) refractory to pharmacological therapy. The ECG showed sinus rhythm with LBBB, and CRT was performed. During implantation of the resynchronizer, repetitive displacement of the CS electrode was observed, requiring implantation of a supporting stent to maintain the electrode inside the cardiac vein. Follow-up of 13 months.
Currently, CRT is part of the therapeutic armamentarium for HF, being indicated in patients with severe ventricular dysfunction refractory to pharmacological therapy and with ventricular desynchronization1.
The procedure is performed with implantation of a lead in the posterolateral LV wall, in addition to the conventional technique used for the atrioventricular pacemaker (right chambers)1. The LV is preferentially stimulated through the transvenous route, via the CS. Displacement of the CS electrode during or after implantation (early or late displacement) is one of the limitations to successful CRT, present in 5%-10% of the cases. That is likely due to the fact that the CS electrode is positioned and maintained in the epicardial cardiac vein passively, making its displacement easy and requiring reintervention. Galvão et als.5 have described the implantation of an anchor electrode aimed at maintaining the electrode inside the CS.
In our five patients, CS electrode displacement was as follows: late, in two; early, in one; and intraoperatively, in two, with lack of CS electrode support. All five patients underwent support stent implantation to fixate the electrode and maintain it in place. All stent implantations were uneventful. Three of our patients required, in addition to resynchronization, an ICD to prevent sudden death, and, in two of them, upgrade to CRT+ICD was performed. This can be due to the difficulty in better stratifying high-risk patients for primary prevention of sudden death6,7.
The use of supporting stent has been shown in case reports and studies with a small number of patients, with satisfactory short- and long-term results and no complications related to the procedure8,9. Nevertheless, it is worth noting the possibility of damage to the electrode's integrity, CS dissection and obstruction, in addition to limitation in electrode removal in cases of diaphragmatic stimulation or infection, requiring surgery10.
Our results were similar to those of the literature. Implantation of supporting stent to prevent displacement of the CS electrode is a safe procedure in the short and long run, once its integrity and position are maintained, thus preserving the basic objective of CRT.
No potential conflict of interest relevant to this article was reported.
There were no external funding sources for this study.
This study is not associated with any post-graduation program.