Bi-ventricular pacing in congestive cardiac failure - Current experience and future directions

Bi-ventricular pacing strategies for heart failure are currently limited or investigational. The aim of biventricular pacing in ventricular failure is to optimize any atrio-ventricular, inter-ventricular or intraventricular electrical asynchrony that accompanies and contributes to the mechanical dysfunction of ventricular disease. Preliminary clinical reports and acute haemodynamic studies have confirmed the potential benefits of biventricular pacing. However, these were confounded by the need for thoracoscopic placement of the left ventricular pacing lead. With the subsequent development of a fully transvenous left ventricular pacing system, the accessibility and safety of biventricular pacing increased markedly allowing the InSync safety and efficacy study to be undertaken. The results of blinded randomized studies investigating this treatment modality are awaited. Furthermore the results with lone left ventricular pacing or more highly selected left ventricular lead positions are required. If these studies confirm functional improvement with biventricular pacing the results of long-term mortality and economic benefit studies will be required before the technique can achieve widespread acceptance. The contribution of combined biventricular ICDs and enhanced lead technology is also awaited.