Far-field R wave sensing causing prolongation of the atrial escape interval of DDD pacemakers with atrial-based lower rate timing.
This report describes the occurrence of prolonged atrial escape intervals (AEI) initiated by sensing of ventricular premature complexes (VPC) without a preceding atrial depolarization or an AV delay in two patients with DDD pacemakers with an atrial-based lower rate response. The prolonged AEIs were due to ventriculoatrial cross-talk so that atrial sensing of the far-field R wave of the VPCs occurred before detection of the R wave by the ventricular channel as a near-field signal. Early atrial sensing of the far-field R wave was promoted by a high atrial sensitivity and/or low ventricular sensitivity and was eliminated by reducing atrial sensitivity and/or increasing ventricular sensitivity. This manifestation of far-field sensing should not be interpreted as malfunction of dual chamber pacemakers with atrial-based lower rate timing.
Barold
S Serge
SS
Tampa General Hospital, Tampa, Florida, USA. ssbarold@aol.com
D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004562:Electrocardiography; D006327:Heart Block / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D012804:Sick Sinus Syndrome / Q000503:physiopathology / Q000628:therapy*