Efecto de la localización del electrodo ventricular izquierdo sobre los parámetros ecocardiográficos de asincronía en pacientes sometidos a terapia de resincronización cardíaca

摘要

Introduction and objectives. Cardiac resynchronizationtherapy has been shown to be an option in the treatmentof patients with congestive heart failure. The currentindication for this treatment is based on clinical and electrocardiographiccriteria, although echocardiography hasalso been shown to be a useful tool for the diagnosis ofventricular dyssynchrony. The aim of this study was to assessleft ventricular dyssynchrony by echocardiographyand to evaluate the effect of the stimulation site on themagnitude of resynchronization.Patients and method. We studied 25 patients with biventricularstimulation (left ventricular lead located in a lateralposition in 13 patients, and in an anterior position in12). A complete echo-Doppler evaluation, including leftventricular ejection fraction, ventricular diameters and parametersof inter- and intraventricular dyssynchrony, wasperformed before implantation and 3 months after theprocedure, with the device connected and disconnected.Results. Left ventricular ejection fraction increased significantlyfrom 23.7 (6.5) to 27.8 (5.5) (P=.007) at 3months. In the group as a whole, biventricular pacing wasassociated with a significant decrease in all intraventriculardyssynchrony parameters (septal-to-lateral wall motiondelay and septal-to-posterior wall motion delay). This decreasein septal-to-posterior wall motion delay and septalto-lateral wall motion delay was significantly greater in patientswith the electrode implanted in the lateral position(58.1 ms vs 118 ms; P=.02) than with the lead in the anteriorposition (39.5 ms vs 86.5 ms; P=.04). Three patients,all with the electrode in an anterior location, were considerednon-responders.Conclusions. Left lateral free wall stimulation providedsignificantly better intraventricular resynchronization comparedto stimulation at an anterior site. Echocardiographyis a useful tool to evaluate changes in intra- and interventricularsynchrony related to the pacing site.