Long-Term Follow-Up of Single-Lead VDD Pacing System

Abstract

Introduction: Single-lead VDD system is an alternative mode of cardiac pacing in patients with atrioventricular (AV) block and preserved sinus node function (SN). The aim of this study was to find the predictors of atrial undersensing in long-term VDD-pacing systems. Methods: Ninety-three patients (80.5±9.6-year-old) with normal SN who received single-lead VDD system and 61 patients (78±11-year-old) with normal SN who received dual-lead DDD system were enrolled. Before the pacemaker implantation, we evaluated 13 parameters (age, gender, type of AV block, hypertension, diabetes, heart failure, ischemic heart disease, atrial fibrillation, chronic renal failure, antiarrhythmic agents, digitalis, calcium channel blocker and atrial amplitude of P wave at implantation). We followed up the patients at our outpatient clinic. Results: In VDD group, Mean follow-up duration was 75±41 months (24–173). Atrial undersensing was detected in 17 patients. According to a Kaplan-Meier analysis, heart failure (P=0.0009), P wave 82 years (P=0.0393) were significant predictor of atrial undersensing. A Cox regression analysis showed that the heart failure was an independent predictor (hazard ratio, 4.525; 95% confidence interval, 1.437–14.286, P=0.0032). Re-operation was required in 3 patients. Conclusion: These results indicate that VDD mode is not preferable in the AV block patient who has a history of heart failure even if the SN and atrial amplitude are preserved.