Long‐Term Stability of P Wave Sensing in Single Lead VDDR Pacing: Clinical Versus Subclinical Atrial Undersensing

Abstract

Optimal function of a single lead P wave synchronous rate adaptive ventricular pacing system (VDDR) requires reliable P wave sensing over time and during daily activities. The stability of P wave sensing and the incidence of sensitivity reprogramming in a single pass lead with a diagonally arranged bipole was assessed in 30 patients with complete atrioventricular block over a follow-up period of 12 +/- 1 months (range 6 months to 3 years). Atrial sensing was assessed during clinic visits, by physical maneuvers (postural changes, breathing, Valsalva maneuver, walking and isometric exercise), maximum treadmill exercise and Holter recordings. P wave amplitude at implantation was 1.21 +/- 0.09 (0.5-3.6) mV, and the atrial sensing threshold remained stable over the entire period of follow-up. Using an atrial sensitivity based on twice the sensing threshold at 1 month, P wave undersensing was found in 2, 4, 3, and 7 patients during clinic visit, physical maneuvers, exercise, and Holter recordings, respectively. Atrial sensitivity reprogramming was performed in three patients based on the correction of undersensing during physical maneuvers. Although eight patients had atrial undersensing on Holter recordings, the number of undersensed P waves was small (total 101 beats or 0.013% +/- 0.001% of total ventricular beats) and no patient was symptomatic. One patient had intermittent atrial undersensing at the highest sensitivity, but the VDDR mode was still functional most of the time. No patient had myopotential interference at the programmed sensitivity. One patient developed chronic atrial fibrillation and was programmed to the VVIR mode. Thus, single lead VDDR pacing is a stable pacing mode in 97% of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

The Impact of the Distance between the Atrial Electrode and the Atrial Wall on Atrial Undersensing in Patients with VDD Pacemakers: Long‐Term Follow‐Up

“…5,[7][8][9] Overall incidence of AUS was 22%. In spite of some methodological differences and vigorousness in the assessment of AUS, our results are comparable to previous reports.…”

VDD pacing in dogs: When, why and how to perform single-lead atrial synchronous, ventricular inhibited (VDD) pacing

“…25 Recommendations in the human literature are to program the atrial sensitivity to 33% of the measured atrial potential to insure tracking through the wide range of P wave amplitudes that will be encountered. 24,26 A second option is to program a very sensitive atrial channel level, i.e. 0.18 mV, and extend the atrial refractory period to avoid oversensing of far-field QRS complexes or ventriculoatrial conduction.…”

“…The system must also overcome acute reductions in the atrial potential post pacemaker implant 22 and individual variations in the atrial potential during physical maneuvers 23,24 and following administration of cardioactive drugs. 25 Recommendations in the human literature are to program the atrial sensitivity to 33% of the measured atrial potential to insure tracking through the wide range of P wave amplitudes that will be encountered.…”

Behavior of an automatic pacemaker sensing algorithm for single-pass VDD atrial electrograms

“…There are several studies that suggest a highest sensitivity for P-wave sensing to compensate the amplitude variation, while there are contradictory studies that concern possible oversensing problems by the highest sensitivities [5][6][7].…”

“…An optimal sensitivity level can not be determined using amplitude measurements of acute atrial electrograms because of the significant amplitude variations [3][4]. I ndividual patients may experience serious P -wave undersensing that may require sensing sensitivity reprogramming or may cause asynchronous pacing.There are several studies that suggest a highest sensitivity for P-wave sensing to compensate the amplitude variation, while there are contradictory studies that concern possible oversensing problems by the highest sensitivities [5][6][7].In this study, a sensing method that adapts its sensitivity level to previous intrinsic amplitude variations, an automatic sensing algorithm, is implemented and evaluated to validate its benefits in atrial electrograms from SVDD leads. The automatic sensing algorithm had been developed for sensing of automatic implantable cardioverter defibrillator (AICD or ICD), and has been adopted by pacemakers recently [8][9].…”