Provoked and spontaneous high-frequency, low-amplitude, respriophasic noise transients in patients with implantable cardioverter defibrillators

Introduction: Ventricular oversensing (OS) of respirophasic noise transient s may cause spurious detections and therapies and pacing inhibition among p atients with implantable cardioverter defibrillators (ICDs), The incidence of OS and its relationship to clinical variables and ICD system design are unknown, Methods and Results: Three hundred twenty-nine patients performed provocati ve respiratory maneuvers at rest during intrinsic rhythm and continuous ven tricular pacing, OS resulting in spurious ventricular detections was provok ed in 3 (0.9%) of 329 patients during intrinsic rhythm and 34 (10.3%) of 32 9 during pacing. Noise transients not recognized and marked as sensed event s, but visually evident on the local endocardial ventricular electrogram, w ere provoked in an additional 23 (7.0%) of 329 patients. Multivariate logis tic regression identified history of spontaneous OS (P < 0.0005, odds ratio 9.7, 95% confidence interval [CI] 1.9 to 50.0). automatic gain control dev ice (P < 0.0005, odds ratio 5.3, 95% CI 2.6 to 10.8) or integrated bipolar lead (P = 0.05, odds ratio 2.6, 95% CI 1.0 to 7.25), and male gender (P = 0 .008, odds ratio 3.7, 95% CI 1.2 to 11.1) as predictive of provocable OS. S pontaneous OS resulting in spurious ventricular detections and therapies oc curred in 12 (3.6%) patients during follow-up. Eleven of 12 spontaneous epi sodes occurred in male patients during ventricular pacing; 11 of 12 patient s had automatic gain control devices and integrated bipolar leads, Conclusion: OS is commonly provoked in ICD patients during ventricular paci ng and may occur spontaneously, causing spurious tachyarrhythmia therapies and pacing inhibition, Differences in the incidence of spontaneous and prov oked OS between ICD systems can be explained on the basis of unique feature s of automatic sensing systems and sensing lead design.