Inhibition of biventricular pacing by far-field left atrial activity sensing: case report.

This case report describes a patient with biventricular pacemaker in whom a far-field sensing of left atrial activity by the pacemaker's ventricular channel resulted in ventricular pacing inhibition. Placing of the left ventricular pacing electrode in the proximal part of the coronary sinus tributary resulted in this far-field sensing problem, which was resolved following decreasing the ventricular sensitivity. The authors suggest that the far-field sensing of the left atrial activity should be kept in mind for troubleshooting of an atrio-biventricular pacing system.