Cyclic pseudo-fusion in a dual chamber pacemaker / Repetidos batimentos de pseudo-fusão em marcapasso de dupla câmara

Studies have shown that avoidance of right ventricular pacing results in a decrease in the incidence of atrial fibrillation and congestive heart failure. Newer algorithms which promote intrinsic conduction and decrease the frequency of ventricular pacing have been developed. However some of these new pacing algorithms are complex and can create potential pitfalls for the clinician. Additionally, these features may not be applicable to a reasonable amount of patients. We describe an example of a pacemaker pseudo-malfunction caused by one of these new algorithms.

Estudos mostram que reduzir o uso de estimulaГЦo ventricular direita em pacientes com marcapasso estА relacionado com menor incidЙncia de fibrilaГЦo atrial e insuficiЙncia cardМaca congestiva. Diante desse novo paradigma, as empresas fabricantes vЙm desenvolvendo novas estratИgias de programaГЦo com objetivo de minimizar a taxa de estimulaГЦo ventricular direita. Entretanto, esses novos modos de programaГЦo sЦo muitas vezes complexos, acarretando dЗvidas sobre o correto funcionamento desses dispositivos. AlИm disso, muitos dos novos modos de programaГЦo podem nЦo ser aplicАveis a uma parcela significativa dos pacientes. Apresentamos um exemplo de programaГЦo de marcapasso visando minimizar a estimulaГЦo ventricular direita, cujo resultado prАtico simula mau funcionamento do dispositivo.

Electrogramas intracardíacos en tiempo real en el diagnóstico de fallas de marcapasos / Real time intracardiac electrograms for the diagnosis of pacemaker malfunction

El desplazamiento crónico del catéter ventricular es una complicación infrecuente del implante de marcapasos. Es infrecuente que un catéter desplazado sense y capture en una cámara donde no fue implantado originalmente. Se presenta el caso de un paciente con marcapasos doble cámara en el que el catéter ventricular se desplazó hacia la aurícula derecha. El catéter desplazado permite sensar y capturar la aurícula. El diagnóstico inicial se realizó mediante el análisis deductivo conjunto de los electrogramas en tiempo real y los eventos en los canales de registro ("marker channel"). La radiografía de tórax confirmó el diagnóstico presuntivo.

Chronic ventricular lead dislodgement is an infrequent complication of pacemaker implantation. Occasionally, the dislodged lead may sense and capture a chamber in which the lead was not originally positioned. Intracardiac real time electrograms and channel markers are useful tools for the diagnosis of pacemaker malfunction. We present the case of a patient with a ventricular lead dislodgement into the atrium. The ventricular lead was able to sense and capture the atrium. Initial diagnosis was performed based on the deductive analysis of intracardiac real time electrograms and channel markers and confirmed by chest X-ray.