title: Usefulness of echocardiography to predict inappropriate atrial sensing in single-lead VDD pacing.
abstract: Reliable atrial sensing is the prerequisite for restoration of atrioventricular synchrony in patients with single-lead VDD pacing systems. To determine echocardiographic variables associated with inappropriate atrial sensing, 21 consecutive patients with symptomatic second- or third-degree AV block and normal sinus node function were studied. Prior to implantation echocardiographic measurements of end-systolic and end-diastolic dimensions and volumes of the right atrium and right ventricle were performed. All patients underwent implantation of a Medtronic Thera VDD(d) pacemaker with a bipolar Medtronic Capsure electrode. A minimal amplitude of the unfiltered atrial electrocardiogram of > or =0.5 mV was required for permanent lead position and the atrial sensitivity was programmed below the lowest recorded value. Appropriate atrial sensing (atrial triggered ventricular paced complexes/total number of ventricular paced complexes) was assessed during 24-hour Holter monitoring and treadmill exercise testing 3 to 6 weeks after implantation. Inappropriate atrial sensing (<95% correct atrial synchronization during Holter registration and/or <97.5% during exercise testing) was present in nine patients. Right atrial volumes and the right ventricular end-diastolic volume was significantly higher, as compared to patients without inappropriate sensing (12 patients). The right atrial and diastolic volumes had the highest correlation with correct atrial sensing r = 0.83, P<0.0001). Using a postdefined cut-off value of > or =80 mL for the end-diastolic right atrial volume, sensitivity and specificity for inappropriate sensing was 100% and 92%, respectively. These findings show that preimplant echocardiography can identify patients with inappropriate sensing during VDD pacing, in whom DDD pacing should be considered.
authors.affiliation: Department of Cardiology, Free University Hospital, Amsterdam, The Netherlands.
authors.forename: C C
authors.initials: CC
authors.lastname: de Cock
authors.forename: L C
authors.initials: LC
authors.lastname: Van Campen
authors.forename: J
authors.initials: J
authors.lastname: Huygens
authors.forename: O
authors.initials: O
authors.lastname: Kamp
authors.forename: C A
authors.initials: CA
authors.lastname: Visser
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial; D004452:Echocardiography; D015716:Electrocardiography, Ambulatory; D005080:Exercise Test; D005260:Female; D006325:Heart Atria / Q000503:physiopathology; D006327:Heart Block / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000628:therapy*; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D012680:Sensitivity and Specificity